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ForewordThe Occupational Safety and Health Act 1984 established the Commission for OccupationalSafety and Health which comprises representatives of employers, unions, government andexperts. The Commission has the function of developing the legislation and supportingguidance material and making recommendations to the Minister for implementation. To fulfilits functions the Commission is empowered to establish advisory committees, hold publicenquiries and publish and disseminate information.

The Commission’s objective is to promote comprehensive and practical preventativestrategies that improve the working environment of Western Australians.

This code of practice has been developed through this tripartite consultative process andthe views of employers and unions along with those of government have been considered.

The following information should be read as background for understanding this code of practice.

The ActThe Occupational Safety and Health Act 1984 provides for the promotion, co-ordination, administration and enforcement of occupational safety and health in Western Australia.

With the objective of preventing occupational injuries and diseases, the Act places certain duties on employers,employees, self-employed persons, manufacturers, designers, importers and suppliers.

In addition to the broad duties established by the Act, it is supported by a further tier of statute, the regulations, together with lower tiers of non-statutory codes of practice and guidance notes.

RegulationsRegulations have the effect of spelling out the specific requirements of the legislation.

Regulations may prescribe minimum standards. They may have a general application or they may define specific requirements related to a particular hazard or a particular type of work.

Regulations may also be for the licensing or granting of approvals, certificates, etc.

Codes of practiceA code of practice is defined in the Act as a document prepared for the purpose of providing practicalguidance on acceptable ways of achieving compliance with statutory duties and regulatory requirements.

Codes of practice:• should be followed, unless there is another solution which achieves the same or better result; and • can be used to support prosecution for non-compliance.

Guidance notesA guidance note is an explanatory document issued by the Commission providing detailed informationon the requirements of legislation, regulations, standards or matters relating to occupational safety and health.

DefinitionsAppendix A defines the terms used in this code of practice.

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AUTHORITYThis code of practice was approved by the Minister for Consumer and EmploymentProtection pursuant to Section 57 of the Occupational Safety and Health Act 1984on 10 November 2004.

SCOPEThis code of practice applies to all workplaces in Western Australia covered by theOccupational Safety and Health Act 1984 where concrete wall panels, whether precast on or off-site, or other precast concrete elements are used in the building and constructionindustry.

It covers the areas of tilt-up and precast concrete construction where safety is a concernincluding casting of panels and other precast elements, handling, storage, transportation,lifting by crane, rigging systems and bracing and securing of panels.

WHO SHOULD USE THIS CODE OF PRACTICE?This code should be used by designers, employers, contractors, self-employed persons,managers, supervisors, persons in control of workplaces, employees and safety and healthrepresentatives to assist them to comply with the Occupational Safety and Health Act 1984and regulations where the tilt-up method of construction and precast concrete elements areused on building and construction sites.

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INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

PART 1: GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91.3 Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.3.1 Notification to WorkSafe Western Australia Commissioner . 91.3.2 Documents on site . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.3.3 Workplan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1.4 Relationship to Australian Standards . . . . . . . . . . . . . . . . . . . 10

1.5 Referenced documents and further reading . . . . . . . . . . . . . . . 10

PART 2: TRAINING, SUPERVISION AND HAZARD MANAGEMENT . . . . . . . . 11

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122.2 Training and supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.3 Safety and health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.4 Hazard management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

PART 3: MATERIALS, COMPONENTS AND EQUIPMENT . . . . . . . . . . . . . . 15

3.1 General – compatibility of components . . . . . . . . . . . . . . . . . . 163.2 Concrete and reinforcement specifications . . . . . . . . . . . . . . . . 163.3 Curing compounds and release agents . . . . . . . . . . . . . . . . . . 163.4 Lifting, bracing and fixing inserts . . . . . . . . . . . . . . . . . . . . . . 17

3.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.4.2 Lifting inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.4.3 Bracing inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.4.4 Fixing inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.4.5 Anchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.5 Re-usable lifting equipment . . . . . . . . . . . . . . . . . . . . . . . . . 183.5.1 Strongbacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183.5.2 Lifting clutches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.6 Braces and props . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193.7 Levelling pads and shims . . . . . . . . . . . . . . . . . . . . . . . . . . . 193.8 Crane and rigging equipment . . . . . . . . . . . . . . . . . . . . . . . . 193.9 Proprietary documentation . . . . . . . . . . . . . . . . . . . . . . . . . . 20

PART 4: DESIGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224.2 Preplanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224.3 Design loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224.3.2 Suction loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234.3.3 Impact loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234.3.4 Wind loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234.3.5 Erection loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4.4 Building stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table of contents

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4.5 Structural design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244.5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244.5.2 Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244.5.3 Design tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.6 Specification of concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . 254.7 Design for manufacture and erection . . . . . . . . . . . . . . . . . . . 26

4.7.1 Design and manufacture . . . . . . . . . . . . . . . . . . . . . . 264.7.2 Additional reinforcement . . . . . . . . . . . . . . . . . . . . . . 264.7.3 Design for erection . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.8 Panel thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294.9 Slenderness effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.9.1 Panel height to thickness ratio . . . . . . . . . . . . . . . . . . 294.9.2 Dual lift slenderness design . . . . . . . . . . . . . . . . . . . . 29

4.10 Panel supports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294.11 Fixing inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.12 Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.13 Brace footings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.13.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.13.2 Floor slabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.13.3 Concrete blocks (deadman) . . . . . . . . . . . . . . . . . . . . 314.13.4 Other footings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.14 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.14.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.14.2 Panel to panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.14.3 Panel to footing or floor slab . . . . . . . . . . . . . . . . . . . 334.14.4 Panel to structural steel . . . . . . . . . . . . . . . . . . . . . . 33

4.15 Strongbacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

PART 5: DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.1 Structural design drawings . . . . . . . . . . . . . . . . . . . . . . . . . . 365.2 Panel documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.2.1 Marking plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365.2.2 Shop drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365.2.3 Erection documentation . . . . . . . . . . . . . . . . . . . . . . . 37

5.3 Lodgement of shop drawings with local government . . . . . . . . 37

PART 6: CASTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396.2 Preplanning and layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396.3 Casting bed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396.4 Formwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406.5 Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406.6 Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416.7 Manufacturer’s statement and inspection . . . . . . . . . . . . . . . . 416.8 Placement and compaction of concrete . . . . . . . . . . . . . . . . . . 416.9 Curing and release agents . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table of contents (continued)

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6.10 Lifting, bracing and fixing inserts . . . . . . . . . . . . . . . . . . . . . 426.11 Element identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426.12 Stripping and repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

PART 7: HANDLING, STORAGE AND TRANSPORT . . . . . . . . . . . . . . . . . . 43

7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447.2 Handling and storage of site-cast concrete panels . . . . . . . . . . 447.3 Handling and storage of factory manufactured

concrete elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447.4 Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

7.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467.4.2 Preplanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467.4.3 Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467.4.4 Support frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467.4.5 Element protection . . . . . . . . . . . . . . . . . . . . . . . . . . 477.4.6 Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

PART 8: ERECTION TO TEMPORARY BRACED CONDITION . . . . . . . . . . . . 48

8.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498.2 Planning the construction and erection sequence . . . . . . . . . . 498.3 Work method statement . . . . . . . . . . . . . . . . . . . . . . . . . . . 508.4 Exclusion zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518.5 Crane standing area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518.6 Planning cranage requirements . . . . . . . . . . . . . . . . . . . . . . . 518.7 Operating near overhead power lines . . . . . . . . . . . . . . . . . . 538.8 Operating near braces and panels . . . . . . . . . . . . . . . . . . . . . 558.9 Working at height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 568.10 Strongbacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578.11 Erection crew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578.12 Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578.13 Erection of concrete panels . . . . . . . . . . . . . . . . . . . . . . . . . 588.14 Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

PART 9: TEMPORARY BRACED CONDITION . . . . . . . . . . . . . . . . . . . . . . 60

9.1 Installation and inspection of temporary bracing . . . . . . . . . . . 619.2 Superimposed loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 629.3 Levelling pads and shims . . . . . . . . . . . . . . . . . . . . . . . . . . 639.4 Grouting of the base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

PART 10: INCORPORATION INTO FINAL STRUCTURE . . . . . . . . . . . . . . . . 64

10.1 Fixing to final structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6510.2 Inspection prior to and removal of braces . . . . . . . . . . . . . . . 65

APPENDIX A: Definitions of terms used in this code . . . . . . . . . . . . . . . . . 66

APPENDIX B: Sample documents, schedules and shop drawing . . . . . . . . . . 69

APPENDIX C: Referenced documents and further reading . . . . . . . . . . . . . . .77

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FIGURES

3.1 Threaded insert

3.2 Load controlled expansion anchors

4.1 Recommended tolerances

4.2 Shear loads and tension loads in edge-lifted concrete panels

4.3 Preferred concrete panel rigging configurations

4.4 Panel rotation

4.5 Various typical panel connections

4.6 Strongbacks

6.1 Crane lifting radius

7.1 Horizontal stacking of factory manufactured concrete panels

8.1 Clearance for cranes from overhead power lines

8.2 High voltage contact

8.3 Snatch block

9.1 Concrete panel bracing, preferred arrangement

9.2 Corner bracing

9.3 Levelling shims

Illustrations

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Introduction

Tilt-up and precast concrete construction is a method of prefabricating concrete in discreteelements and erecting and incorporating them by crane into their final position in a structure.

This code of practice sets out industry-wide guidelines for establishing and maintaining a safeworking environment wherever tilt-up and precast concrete construction is used.

The tilt-up and precast concrete industry, from design to completion of construction, should beaware of its obligations to protect employees, contractors and members of the public underthe Occupational Safety and Health Act 1984, regulations and codes of practice.

This code provides practical advice about the safe design, manufacture, transport, cranage,storage, erection and stablilisation of concrete wall panels and other precast concreteelements. The emphasis is on ensuring a safe working environment whenever these elementsare used.

Advice can also be found in Australian Standards and other documents referenced in this code.

This code is based on current knowledge and construction methods within the industry and isnot intended to exclude other methods or processes that can be shown to meet therequirements of providing a safe workplace.

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PartGeneral1

C O N T E N T S

PAGE

1.1 Purpose..................................................................... 9

1.2 Scope .........................................................................9

1.3 Regulations ............................................................... 91.3.1 Notification to WorkSafe Western Australia

Commissioner................................................... 91.3.2 Documents on site........................................... 91.3.3 Workplan ........................................................ 10

1.4 Relationship to Australian Standards ..................... 10

1.5 Referenced documents and further reading........... 10

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1.1 Purpose The purpose of this code is to providepractical guidance on the design andconstruction of structures using concrete wallpanels and other precast concrete elements;to ensure, as far as is practicable, a safeworking environment for those in the industry.

1.2 Scope The code covers the safe design,manufacture, transport, cranage, storage,erection and stabilisation of:

• concrete wall panels, whether precast onor off-site, and their use in the buildingand construction industry; and

• other precast concrete elements andtheir use in the building andconstruction industry.

The Definitions of terms used in this codeare contained in Appendix A.

1.3 RegulationsRegulations 3.88 to 3.88J apply to themanufacture of concrete wall panels,including retaining walls, whether precaston site or off-site, and to tilt-up work asdefined.

The regulations do not apply to otherprecast concrete elements.

However, this code of practice offerspractical guidance on complying with therequirements of the regulations as well aspractical guidance on the safe use of otherprecast concrete elements.

1.3.1 Notification to WorkSafe WesternAustralia Commissioner

The Commissioner must be notified ofthe intention to manufacture concretepanels as defined.

No casting of concrete panels or tilt-upwork as defined (other than workrelating to the manufacture of theconcrete panel prior to casting) may becarried out without this notification.

For concrete panels cast on-site it is thebuilder’s responsibility to ensurenotification requirements are met. Forconcrete panels cast off-site thisresponsibility rests with the employer orself employed person who is alsorequired to provide a copy of the noticeto the builder.

The notification is made by completing aform available from WorkSafe andprovided to the Commissioner at least10 working days before casting of theconcrete panels is intended to begin.

The notification must provide theCommissioner with the followinginformation:

• the construction site or otherworkplace where the casting is totake place; and

• the construction site where theconcrete panel is to be installed.

1.3.2 Documents on site

Regulation 3.88G requires the followingdocuments be kept at the site at alltimes when tilt-up work is being carriedout:

• a copy of the notification to theCommissioner referred to in section1.3.1 above;

• a copy of any exemption from therequirements of the regulationsgranted by the Commissioner underRegulation 2.12, in relation to thework;

• a copy of the shop drawings (seesection 5.2.2);

• a current plan setting out details ofthe proposed execution of the worktogether with a copy of any relatedinstructions or diagrams receivedfrom an engineer by the builder (seesection 1.3.3); and

• a copy of the inspection report of theformwork set-up referred to in AS3850 section 4.10 (see section 6.7)for each concrete panel.

General

Regulation 3.88G

Regulation 3.88B

Regulation 3.88A

Regulation 3.88F

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A copy of AS 3850 and this code ofpractice should also be available at the site.

See section 6.7 regarding themanufacturer’s statement and the needfor it to be available on site at the timeof lifting the concrete elements.

A copy of the relevant local governmentbuilding licence should be kept at thesite.

1.3.3 Workplan

Regulation 3.88G requires that an up todate plan that sets out details of theproposed execution of the work be atthe workplace whenever tilt-up work iscarried out.

A copy of the workplan should belodged with the relevant localgovernment authority for filing with therelevant building licence. The Departmentof Local Government and RegionalDevelopment intend to make thislodgement a requirement of the BuildingRegulations 1989. Information containedin the workplan will greatly assist thesafety of any future demolition work.

The workplan should contain thefollowing information:

• proposed sequence of work andproposed work method statement(see sections 8.2 and 8.3 of thiscode). Prior to manufacturing theconcrete elements, the completeconstruction and erection sequencesshould have been planned;

• methods of stabilisation (temporaryand permanent) of the structure. Themethod of stabilising the structurewhile concrete panels are beingerected needs to guard againstcollapse of a panel and progressivecollapse of the structure. The methodneeds to ensure adequate structuralstrength and continuity of thestructure and its parts while being

erected, or in its finished form, tosafely transmit applied loads throughthe structure (see section 4.4 of thiscode). Of critical importance is thestability of the structure while roofmembers are being erected. See AS3828, Guidelines for the erection ofbuilding steelwork;

• traffic management plan (see section7.4.6 of this code);

• job safety analysis and riskassessment (see section 2.4 of this code); and

• signed copies of any changes madeto specifications and/or signedinstructions, advice or diagramsmade or issued by an engineer.

Information and guidance on theserequirements may also be found in AS 3850.

1.4 Relationship toAustralian Standards Regulations 3.88 to 3.88J require, amongstother things, that the design, manufacture,transport, cranage, storage, erection andstabilisation of concrete panels be carriedout in accordance with the relevant parts ofAS 3850.

This requirement underpins most of theinformation contained in this code.

This code is intended to complement AS 3850 and other key Australian StandardsAS 3600, AS 3610 and AS 3828 dealingwith tilt-up and precast concrete structures.

Other relevant Australian Standards arereferenced in this code.

1.5 Referenced documentsand further reading Appendix C provides a list of documentswhere further information may be obtained.

Regulation 3.2

Regulation 3.88G

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2C O N T E N T S

PAGE

2.1 General .....................................................................122.2 Training and supervision ........................................ 122.3 Safety and health.................................................... 132.4 Hazard management ............................................... 13

PartTraining, supervision

and hazard management

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2.1 General A principal objective of Western Australia’sOccupational Safety and Health Act 1984 isto promote safe working environments andto prevent harm to employees at work. Todo this, it imposes duties of care onemployers, employees, and others, andrequires employers and employees to co-operate in ensuring that workplaces andwork practices are safe and without risks tohealth.

One of the employer's primary duties underthe Act is to provide:

“such information, instruction, and trainingto, and supervision of, his employees as isnecessary to enable them to perform theirwork in such a manner that they are notexposed to hazards.”

Employers owe this same duty of care toindependent contractors and thecontractor’s employees working at theworkplace. The Commission forOccupational Safety and Health GuidanceNote General Duty of Care in WesternAustralian Workplaces provides detailedinformation on the duty of care.

In fulfilling this obligation, there should bea structured system of education andtraining to enable both employers andemployees to:

• identify and manage the risks involvedin the manufacture, transport, cranage,storage, erection and stabilisation ofconcrete panels and precast concreteelements; and

• keep abreast of the current state ofknowledge within the industry on themeans of eliminating hazards andcontrolling risks to safety and health.

2.2 Training and supervision Employees need to work safely. Theyshould be trained and instructed in safesystems of work and safe work practices.

The builder must ensure that themanufacture of concrete panels and othertilt-up work is directly supervised by aperson who has completed an approvedtraining course for managers andsupervisors in the construction industryregarding the manufacture of concretepanels or other tilt-up work as appropriate.

Approved training course means a trainingcourse approved by the WorkSafe WesternAustralia Commissioner.

Direct supervision means oversighting thework while it is being carried out havingregard to ensuring by way of direction,demonstration, monitoring and checkingthat the work is being performed in a safemanner in accordance with agreedprocedures (the work plan) and ensuring acapacity to respond immediately in anemergency.

The builder must also ensure that allpersonnel involved in the manufacture ofconcrete panels or other tilt-up work havecompleted an approved training courseconcerning the aspect of the work in whichthe person is involved.

Training programs should include:

• induction on this code and AS 3850;

• first aid training to the minimumrequirements of the Commission forOccupational Safety and Health Code ofPractice for First Aid Facilities andServices;

• identification of hazards associated withthe use of plant and equipment; and

• the selection, fitting, care, use andstorage of protective clothing andequipment.

The Act, section 19 (1)(b)

Training, supervision and hazard management

Regulation 3.88Iand 3.88J

Regulation 3.88Iand 3.88J

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All personnel directly undertaking casting,transport, cranage, storage, erection andstabilisation of panels will be undertaking tilt-up work. Other personnel working on a sitewhile casting of panels through to permanentstabilisation is being carried out may also beundertaking tilt-up work as defined.

A risk assessment should be carried out todetermine which of these other personnel,and any visitors to the site, require training,and the extent of this training.

2.3 Safety and healthEmployers should ensure that all employeeshave the opportunity to be fully involved inthe development of procedures includinghazard identification, assessment of riskand methods used to control the risk.

In particular, they need to take allpracticable steps to:

• provide and maintain a safe workingenvironment;

• provide and maintain facilities for thesafety and health of employees;

• ensure that machinery and equipment isdesigned, manufactured, set up andmaintained to be safe for employees;

• ensure that employees are protectedfrom hazards in the course of their work;

• provide procedures to deal withemergencies that may arise whileemployees are at work; and

• consult and co-operate with safety andhealth representatives, if any, and otheremployees at the workplace regardingsafety and health at that workplace.

Before commencing work on a project,employees should be informed by theiremployer of:

• hazards they may be exposed to whileat work;

• hazards they may create while at workthat could harm other people;

• how to minimise the likelihood ofhazards becoming a source of harm tothemselves and others;

• the location and correct use of safetyequipment; and

• emergency procedures.

Employers should inform employees of theresults of any safety and health monitoringcarried out in the workplace.

Employers, so far as practicable, are alsoresponsible for the safety and health ofpeople who are not employees. Employersneed to take all practicable steps to ensurethat the work of the employer or employeesdoes not harm any other person while atwork, including members of the public orvisitors to the workplace.

Employees are responsible for their ownsafety and health while at work and shouldtake reasonable care to ensure that theiractions do not harm or place others at risk.One of their obligations is to co-operatewith their employer on safety and healthmatters and not to interfere with or misuseanything provided by their employer toprotect safety and health.

2.4 Hazard management Employers need to have in place aneffective method to identify hazards and todetermine whether there are significanthazards that require further action. A hazardis an existing, new, or potential situation orevent that could result in injury or harm tohealth.

In the tilt-up and precast concrete industry,risk is always present when handling,transporting and erecting concreteelements. Although failure of material,components or equipment is rare theconsequences are always significant.

To ensure appropriate hazard management,an identification of the hazards and anassessment of the risks from these hazardsshould be carried out by the builder inconjunction with the safety and healthrepresentatives of the contractors andworkers involved in the work.

A job safety analysis that lists the hazardsand suggests safety procedures should beprepared. The minimum requirements forthis job safety analysis include:

• an identification of the hazards;

• an assessment of the risks from thehazards identified;

• control measures required to eliminate orminimise the risks from the hazards; and

The Act, section 21

The Act, section 20

14

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• identification of the person responsiblefor implementing and monitoring thecontrol measures.

Where possible, the hazard should beeliminated or the risk reduced by changingor modifying the proposed work method orconstruction method, or by use ofalternative equipment.

Where the hazard cannot be eliminated,control measures should be implemented toisolate the hazard and to minimise risk toemployees. In these circumstances,measures such as barricading areas ofdanger, provision of specific safety training

and work instructions, use of protectiveequipment, and posting of warning signsshould be implemented. Such measuresshould be discussed with employees andevaluated to ensure that they are effectiveand do not create additional hazards.

The accepted means of planning to preventinjury is to identify hazards and then assessand control the risk. At the control stagethere is a recognised hierarchy of hazardcontrol measures that should be applied.These processes for managing risk shouldbe followed as part of the hazardmanagement process.

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C O N T E N T S

PAGE

3.1 General – compatibility of components ................. 16

3.2 Concrete and reinforcement specifications............. 16

3.3 Curing compounds and release agents .................. 16

3.4 Lifting, bracing and fixing inserts........................... 173.4.1 General......................................................... 173.4.2 Lifting inserts ............................................... 173.4.3 Bracing inserts ............................................. 173.4.4 Fixing inserts................................................ 173.4.5 Anchors ........................................................ 18

3.5 Re-usable lifting equipment.................................... 183.5.1 Strongbacks ................................................. 183.5.2 Lifting clutches............................................. 19

3.6 Braces and props.................................................... 19

3.7 Levelling pads and shims....................................... 19

3.8 Crane and rigging equipment ................................. 19

3.9 Proprietary documentation..................................... 20

3PartMaterials, componentsand equipment

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3.1 General – compatibilityof componentsAll materials, components and equipmentshould comply with the relevant AustralianStandards, in particular the requirements ofAS 3850.

All components used on site within aparticular system should be compatible anddifferent proprietary components should notbe mixed without verification ofcompatibility. Verification of compatibilityshould be obtained from suppliers and thedesigner of any other equipment to beused.

Incompatibility of different types of insertsor sizes may lead to failure. This isparticularly relevant to lifting inserts, bolts,ferrules and lifting clutches.

3.2 Concrete andreinforcement specificationsThe strength of the concrete at initial liftingand for the in-service condition should notbe less than the value specified on theshop drawings.

Testing of concrete and verification ofconcrete strength should be determined inaccordance with the requirements of theappropriate parts of AS 3600 and AS 1012.

3.3 Curing compounds andrelease agents Before a release agent is chosen for use inthe manufacture of a concrete element, itshould be checked for compatibility withthe curing compound and other appliedfinishes and joint sealants. A provenproprietary combination curingcompound/release agent can be used.Specialist advice may be necessary from themanufacturer or supplier of the product orproducts used.

Consideration should be given to thefollowing factors:

• solubility - the product should not beable to be washed off by rain;

• temperature effects – exposure toextreme temperatures should not blisterthe product and cause it to lose itsproperties;

• compatibility with finishes - theadherence of applied finishes, includingjoint sealants, should not be affected bythe curing compound and releaseagents; and

• discolouration - if it is a pigmentedproduct, the pigmentation shouldweather off within a reasonable time.

If any curing compound or release agent orproprietary combination product is ahazardous substance in accordance withregulation 5.3, a Material Safety Data Sheet(MSDS) must be supplied by themanufacturer and made available to allworkers who may be exposed to thesubstance. The builder must consult with allworkers who might be exposed to thesubstance about the intention to use thesubstance and the safest method of use.Workers likely to be exposed must receivetraining on health risks, control measuresand correct use in accordance withregulation 5.21. They must also be informedabout the need for, and details of, healthsurveillance.

Part 5 of the Occupational Safety andHealth Regulations 1996 provides furtherinformation on the responsibilities ofpersons who manufacture or supplyhazardous substances and those who areresponsible for their use at workplaces.

The strength, watertightness and durabilityof concrete depends on the concrete beingadequately cured. Curing compounds andrelease agents should comply with AS 3799.

Materials, componentsand equipment

Regulation 5.21

Regulation 5.3

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3.4 Lifting, bracing andfixing inserts

3.4.1 General

Lifting, bracing and fixing inserts shouldcomply with the requirements of AS 3850.

All lifting, bracing and fixing insertsshould be manufactured from ductilematerials and site welding ofreinforcement to inserts (other than weldplates) should not be carried out.

Product documentation for proprietaryinserts should be provided by thesupplier, available on site and includefull technical specifications, make, typeand working load limit (WLL).

If non-proprietary inserts are used theyshould be designed in accordance withthe appropriate Australian Standard byan engineer to be compatible with theother parts of the system with whichthey are to be used.

The type and capacity of lifting, bracingand fixing inserts should be specified onthe shop drawings. They should not bechanged without prior approval of theerection design engineer.

3.4.2 Lifting inserts

Lifting inserts within a concrete panelshould be specified as cast-in products.Where cast-in inserts are found to beunusable after casting, approval shouldbe obtained from the erection designengineer to use an alternative type priorto installation.

Lifting inserts should be designed,manufactured and installed to provide aWLL with a limit state factor of at least2.5 against concrete failure. In determiningthis, the applied load needs to includethe mass of the element as well assuction and impact load due to lifting.

Prestressing strand is not suitable aslifting inserts and should not be used.The strand may bend and weaken at thepoint of exit from the concrete.

Steel reinforcement bar is also notsuitable as lifting loops and should notbe used. Certain high tensile strengthsteel bar has properties that make itsuitable only to resist tensile forces and

should not be used in any part of aninsert anchorage.

3.4.3 Bracing inserts

Bracing inserts within a concrete panelshould be cast-in products wherepossible. Where cast-in inserts are foundto be unusable after casting, approvalshould be obtained from the erectiondesign engineer to use an alternativetype prior to installation.

Bracing inserts should be designed,manufactured and installed to provide aWLL with a limit state factor of at least2.5 against concrete failure. Indetermining this, the applied load needsto include all expected loads includingconstruction loads and wind loads.

Where cast-in bracing inserts are notused in brace footings, an acceptablealternative is the use of drilled throughfixings, undercut anchors or loadcontrolled expansion anchors.

3.4.4 Fixing inserts

Fixing inserts for the panel connection toroof framing and other structuralmembers should be designed inaccordance with the appropriateAustralian Standard and the BuildingCode of Australia (BCA) to resist theforces imposed on the connections.

Cast-in fixings such as threaded inserts,weld plates or brackets should be usedwhere possible. They need to be fullyanchored to transfer load into theconcrete.

Anchorage and load transfer forthreaded inserts is achieved by acrossbar fitted through a cross-hole (see Figure 3.1).

Figure 33.1: TThreaded iinsert

Internally threaded cross-holed ferrule, 20 mm minimum diameter

May haveenlarged base

Anchor bar

Design

depth

for co

ne fail

ure

This illustration hasbeen reproducedfrom the Tilt-upConstruction NotesT50, 1997 withpermission ofCement Concrete &Aggregates Australia

18

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Where possible, fixings should bestandardised for all panels on anindividual project to minimise thechance of error.

Where permanent fixings or connectionsare to be also utilised for temporary useduring construction, the builder or theerector should verify that such use willnot compromise their long-termperformance.

3.4.5 Anchors

Expansion anchors are either loadcontrolled or deformation controlled as defined in Appendix A. Only loadcontrolled (see Figure 3.2) are permittedin tilt-up and precast concreteconstruction. Where these anchors areused, the WLL should be limited to 0.65of the first slip load determined inaccordance with AS 3850.

Anchors used should be tested inaccordance with Appendix A3.2 of AS 3850.

Deformation controlled expansionanchors, including self drilling, drop inand spring coil anchors should not beused because they may fail withoutwarning, are highly sensitive toinstallation procedures and have noadditional load capacity after the initialsetting process.

Expansion anchors should bemanufactured from ductile material.

Chemical anchors relying on chemicaladhesion should not be used becausethey may fail without warning and arehighly sensitive to installationprocedures.

Expansion anchors are more susceptibleto installation errors than drilled-throughfixings. A calibrated torque wrenchshould be used to ensure correctinstallation torque is achieved wheninstalling expansion anchors, and specialattention needs to be given to thecorrect drilling of the holes.

There needs to be an adequate checkingsystem to ensure expansion anchors areinstalled correctly.

With brace footings, the capacity ofanchors may be less than the capacity of

the brace itself requiring additionalbraces to support the panel. The use ofinserts with higher capacities may avoidthis. As mentioned in section 9.1 of thiscode there is difficulty in ensuring aneven load distribution where more thantwo braces are used.

Figure 33.2: LLoad ccontrolled eexpansionanchors

Example of load controlled (torquecontrolled) heavy duty safety anchors

3.5 Re-usable liftingequipment

3.5.1 Strongbacks

Concrete panels that are odd shaped,elongated or with large or awkwardlypositioned openings may require theaddition of steel strongbacks to enablethem to be successfully lifted andplaced.

Strongbacks may be used to strengthenthe panels or to locate additional liftingpoints to prevent out-of-plane rotationof odd-shaped panels.

Where strongbacks are used, theirweight needs to be included in thecalculation to determine the weight ofthe panel and its centre of gravity forlifting purposes.

Strongback fixing inserts should beeither cast-in ferrules or load controlledexpansion anchors.

High strength internal bolt

Close fitting heavywall distance sleeve

Internally tapered expansion joint

This illustration hasbeen reproduced fromthe “Precast ConcreteHandbook” withpermission from theNational PrecastConcrete AssociationAustralia.

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3.5.2 Lifting clutches

Lifting clutches should be designed witha limit state factor of 5. Lifting clutchesshould be proof tested to a load of 2times the WLL, certified and individuallyidentified by permanent marking orattachment of a durable tag prior to use.

A proof test using a load equal to 1.2times the WLL should be conducted andrecorded at least at 12 monthly periods.

3.6 Braces and props The safe erection of concrete panels andprecast concrete elements relies, to a largeextent, on the integrity of the braces andprops used and their correct installation.

Bracing and propping systems should bedesigned to resist all expected loads,including:

• construction loads; and

• wind loads for temporary structures inaccordance with AS/NZS 1170.2.

Braces should have a permanently fixedidentification plate displaying the followinginformation:

• the supplier or manufacturer; and

• the model type or designation.

In addition, the load capacity of the bracesshould be marked as follows:

• for fixed length braces, WLL, inkilonewtons (kN), on the permanentidentification plate;

• for adjustable length (telescopic) braces,the WLL, in kN, at maximum and atminimum extension, on the permanentidentification plate; and

• for composite braces, the WLL, in kN, atmaximum and at minimum extension,and at intermediate positions, suitablyand clearly marked on the brace.

The WLL for braces at maximum andminimum extension should be determinedin accordance with the requirements of AS3850, taking into account the forces andeccentricities associated with the completeassembly of components that comprise thebrace. Where this involves testing, suchtests should be conducted by a registeredNational Association of Testing Authorities

(NATA) laboratory or equivalent. Bracesshould be designed with a limit state factorof at least 2 against failure.

Brace adjustment mechanisms should havestops on the threads to prevent over-extension and retaining devices to preventunintentional dislodgment of the shear pin.The shear pin should be purpose made,simple to install and be constructed so thatit cannot be undone without the use ofappropriate equipment or the application ofdeliberate force.

The WLL for props should be supplied bythe manufacturer.

Brace and prop requirements and details foreach type of concrete panel or precastconcrete element should be clearly specifiedon the shop drawings. Where applicable,this includes requirements and details forknee bracing and any other secondarybracing required.

Braces sshould nnever bbe uused aas pprops aandprops sshould nnever bbe uused aas bbraces.

3.7 Levelling pads and shims Levelling pads and shims should complywith the relevant requirements of AS 3850.

Unless designed and specified otherwise,shimming should be a maximum height of40 mm, a minimum length of 150 mm and aminimum width of 100 mm.

3.8 Crane and riggingequipment Crane charts should be used to determinethe required crane capacity. The correctselection of cranes, however, requires thatthe configuration of the crane (its locationin relation to the lift) needs to beconsidered as well as the actual load that isto be lifted. The actual load should includethe weight of the lifting gear, crane blockand rope and any strongbacks.

Cranes should be selected and operated inaccordance with the appropriate parts of AS2550.

All rigging equipment should comply withthe relevant Australian Standards and havea WLL adequate for its intended application.It should be in a serviceable condition.

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The selection of the rigging gear usedduring lifting and erection of concreteelements should ensure the rigging is notsubjected to forces for which it has notbeen designed.

Snatch blocks and other sheave blocksneed to be equipped with thrust races orseparate swivel bearings if rotation ofsheave block swivels under load isunavoidable. Blocks with standard plainbearings are not intended to be rotatedunder load.

3.9 ProprietarydocumentationProprietary documentation should set outthe information required for the correct useof the component or system. It shouldinclude the following information, whereapplicable:

• drawings that clearly identify thecomponent or system to which it refers;

• adequate information to fully describeits intended use;

• instructions for use, storage andmaintenance, including all precautions tobe observed in its use;

• criteria for rejection and reworking ofthe component or system;

• detailed information including, whereappropriate, the following:

- part number;

- dimensions;

- section properties;

- self-weight;

- details of any special attachments, eg coupling sleeves; and

- locations for attachment points andbracing points;

• the strength and serviceability limit statecapacities;

• the WLL; and

• a statement that the component orsystem depicted in the documentationcomplies with AS 3850.

Proprietary documentation should be readilyavailable on site, if required. Fulldocumentation need not be held on sitebut should be obtainable within areasonably short period.

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PartDesign4

C O N T E N T S

PAGE4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.2 Preplanning . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.3 Design loads . . . . . . . . . . . . . . . . . . . . . . . . 224.3.1 General . . . . . . . . . . . . . . . . . . . . . . . 224.3.2 Suction loads . . . . . . . . . . . . . . . . . . . 234.3.3 Impact loads . . . . . . . . . . . . . . . . . . . . 234.3.4 Wind loads . . . . . . . . . . . . . . . . . . . . . 234.3.5 Erection loads . . . . . . . . . . . . . . . . . . . 23

4.4 Building stability . . . . . . . . . . . . . . . . . . . . . . 23

4.5 Structural design . . . . . . . . . . . . . . . . . . . . . . 244.5.1 General . . . . . . . . . . . . . . . . . . . . . . . 244.5.2 Fire . . . . . . . . . . . . . . . . . . . . . . . . . . 244.5.3 Design tolerances . . . . . . . . . . . . . . . . 25

4.6 Specification of concrete . . . . . . . . . . . . . . . . 25

4.7 Design for manufacture and erection . . . . . . . . 264.7.1 Design and manufacture . . . . . . . . . . . . 264.7.2 Additional reinforcement . . . . . . . . . . . . 264.7.3 Design for erection. . . . . . . . . . . . . . . . 26

4.8 Panel thickness. . . . . . . . . . . . . . . . . . . . . . . 29

4.9 Slenderness effects . . . . . . . . . . . . . . . . . . . . 294.9.1 Panel height to thickness ratio . . . . . . . 294.9.2 Dual lift slenderness design. . . . . . . . . . 29

4.10 Panel supports . . . . . . . . . . . . . . . . . . . . . . . 29

4.11 Fixing inserts . . . . . . . . . . . . . . . . . . . . . . . . 30

4.12 Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.13 Brace footings. . . . . . . . . . . . . . . . . . . . . . . . 314.13.1 General. . . . . . . . . . . . . . . . . . . . . . . . 314.13.2 Floor slabs . . . . . . . . . . . . . . . . . . . . . 314.13.3 Concrete blocks (deadman) . . . . . . . . . . 314.13.4 Other footings . . . . . . . . . . . . . . . . . . . 31

4.14 Connections . . . . . . . . . . . . . . . . . . . . . . . . . 314.14.1 General. . . . . . . . . . . . . . . . . . . . . . . . 314.14.2 Panel to panel . . . . . . . . . . . . . . . . . . . 314.14.3 Panel to footing or floor slab . . . . . . . . 334.14.4 Panel to structural steel . . . . . . . . . . . . 33

4.15 Strongbacks . . . . . . . . . . . . . . . . . . . . . . . . . 34

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4.1 General In tilt-up and precast concrete constructionthere are two separate phases of design.

The first, the in-service or structural design,is for the in-service condition and is usuallycarried out by the project design engineeras part of the design of the completestructure. The in-service design provides forthe performance of the concrete panel orprecast concrete element as part of thecomplete structure. The project designengineer needs to be experienced in thefield of precast construction.

The second, the design for erection, is forthe handling, transportation, erection andbracing of the individual concrete elementsduring the erection process. It may becarried out independently of the structuraldesign by the erection design engineer.During the braced condition the structuremay be regarded as a temporary structureand particular care is required to minimisethe risk of progressive collapse.

The structural design should take intoaccount the particular requirements ofprecast concrete structures to ensure thatthe elements can be safely erected withoutany component failure occurring.

Important obligations under the OccupationalSafety and Health Act 1984 are placed onthose who design or construct any buildingor structure, including a temporary structure,to have regard for persons who are to erector use the structure. Section 23 (3a) of theAct states that:

“A person who designs or constructs any building or structure, including a temporary structure, for use at aworkplace shall, so far as is practicableensure that the design and constructionof the building or structure is such that –

(a) persons who properly construct,maintain, repair or service thebuilding or structure; and

(b) persons who properly use thebuilding or structure,

are not, in doing so, exposed to hazards.”

The structural design should also giveconsideration to the safety of any futuredemolition of the building or structure.

4.2 Preplanning Preplanning and close co-ordinationbetween the relevant parties is essential toensure safety in the use of concrete panelsand precast concrete elements.

It is not possible to obtain the full benefitand economies inherent in their use withoutpreplanning and co-ordination between therelevant parties.

Prior to preparation of the shop drawings,the parties involved in the design,manufacture, transport and erection processshould liaise to plan the completeconstruction and erection sequences.Consideration needs to be given to detailssuch as site limitations, local street access,delivery sequence, transport requirements,cranage requirements and overheadobstructions. These aspects can have asignificant effect on the size of concreteelements and on the erection process.

The floor slab should be designed to caterfor all construction loads likely to occur,such as from cranes and concrete trucks.

4.3 Design loads

4.3.1 General

As well as the in-service design,concrete panels and precast concreteelements need to be designed for theloads and conditions likely to beexperienced during the manufacturing,lifting, transportation and erectionphases.

Consideration should be given to thefollowing:

• handling loads;

• storage and transport loads whereapplicable;

• erection loads;

The Act, section 23(3a)

Design

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• construction loads including anybackfill and surcharge loads;

• permanent, imposed and other loadsin accordance with AS/NZS 1170.1;

• wind load in accordance with AS/NZS 1170.2 on the bracedelements; and

• seismic load in accordance withAS/NZS 1170.4.

The increase in design loads due towind load and seismic load is notcumulative.

The effect of suction and adhesion atseparation from the form or casting bed(lift-off) and dynamic and impact loadingduring transportation, erection andbracing should also be considered.

4.3.2 Suction loads

Suction loads are reduced by use of anappropriate release agent (see section3.3 of this code) and will vary accordingto the finish of the concrete panel andthe type of form or casting bed.Recommended minimum values are:

• for concrete cast onto a steel bed, a20% increase should be applied tothe dead load;

• when casting concrete onto concretecasting beds, a 50% increase shouldbe applied to the dead load; and

• where the casting bed has a profiledor textured surface the "suction" loadmay exceed 100% of the dead load.

Consideration should be given to thecasting bed profile to ensure thatadequate draw (slope) is provided to thefixed edges of the form not struck priorto lifting. A minimum draw of 1:12 isrecommended.

4.3.3 Impact loads

Impact loads generated during handlingand transport can be significant andneed to be considered in the design ofthe lifting inserts and rigging systems.These increases may range from 20%during handling by crane to up to 100%during transportation.

Impact loading should only beconsidered after release (lift-off) of the

concrete panel from the casting bed. Theincrease in design loads due to suctionand impact is not cumulative.

4.3.4 Wind loads

Wind loading on concrete panels willvary depending on the size of thepanels, wind speed and wind direction.In built-up areas the wind effect may beless than in open areas although“funnelling” effects can increase windloading in built up areas.

In cyclone prone areas of the State thepotential wind loading applied to panelswill be greater. Sudden and severe windgusts frequently occur throughout theState particularly in coastal areas.

Generally wind loading varies directly tothe square of the wind speed and smallincreases in wind speed will result inmuch higher loadings. This may result inthe need for more braces to be providedor a larger brace footing.

4.3.5 Erection loads

Concrete panels and precast concreteelements need to be designed for theloads and conditions likely to beexperienced during the manufacturing,lifting, transportation, erection, bracedand in-service phases in accordance withAS 3850 and AS 3600.

Erection load design should considervariations to the load-distribution on theconcrete elements during lifting, rotationand impact during placement.

4.4 Building stability It is the responsibility of the builder toensure the stability of the structure duringthe erection phase.

The stability of the building for the in-service condition is the responsibility of theproject design engineer.

The stability of the whole building shouldbe checked for each stage during erectionand under in-service load conditions.Special care needs to be taken in designand construction to guard againstprogressive collapse both duringconstruction and in the completed structure.

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Tilt-up concrete structures are susceptibleto progressive collapse type failures. Thefailure of a single member such as a roofbracing member due to an event such asfire, accident or other cause, should notlead to the complete collapse of thestructure. Consideration also needs to begiven to the situation during constructionwhen the dislodgement of a single concretepanel could lead to progressive collapse.

Progressive collapse may be prevented byproviding either:

• adequate structural strength andcontinuity of the structure and its parts;or

• alternative load paths that cause appliedforces to be safely transmitted throughthe structure.

Structural continuity may rely upon, amongother things, moment, shear or tensileconnections, depending on the kind ofstructural system employed.

The workplan referred to in section 1.3.3 ofthis code includes documented methods ofstabilisation, both temporary and permanent,of the structure. In considering methods ofstabilisation, the requirements of AS 3828should be taken into account.

4.5 Structural design

4.5.1 General

The structural design of the concreteelements should be carried out inaccordance with the requirements of AS3850 and AS 3600, as appropriate, andthe provisions of this code.

See section 8.14 of this code regardingapprovals necessary for modifications toany concrete elements, including thedesign.

Slenderness and stability are majorconsiderations in the design of concreteelements. Precast concrete constructionmay lack the continuity inherent in castin-situ concrete structures. The buildingdesigner and project design engineerneed to address these issues for the in-service condition while the builder and

erection design engineer should considerthem during the erection phase of thestructure.

Structural members supporting concreteelements should be designed to allowfor the situation where the concreteelement bears on only two discreteshimming points during erection. Theerection sequence of concrete panelscan produce more adverse loadingconditions in a supporting member thanthe final in-service loads.

4.5.2 Fire

The Building Code of Australia (BCA)sets out the requirements for the designof buildings against fire. It specifies thefire resistance level (FRL) for variousbuilding elements. The FRL depends onthe type of construction, determined forthe occupancy class of building andheight in stories, and proximity to thefire source. The FRL gives the fireresistance periods (FRP) for structuraladequacy, integrity and insulation. AS3600 provides methods for determiningthe FRP of concrete members. Concretepanels should comply with theserequirements. AS 4100 provides periodsof structural adequacy for the steelelements of the building.

Joints between the panels should alsosatisfy the appropriate FRP and notadversely affect the behaviour of the wall.

In addition to setting out therequirements for the design of buildingsagainst fire, the BCA also sets outrequirements for the performance ofbuildings subject to fire. Theserequirements are set out in Part C 1.11,Performance of external walls in a fire.To comply, the concrete panel designwill require connection details such thatthe panels during and after a fire willeither remain standing or tend tocollapse inwards.

Detailed information on the design oflightly loaded wall panels is available inRecommended Practice, Design of Tilt-upConcrete Wall Panels referenced inAppendix C.

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4.5.3 Design tolerances

Because concrete elements cannot bemanufactured to exact dimensions,provision needs to be made in thedesign for dimensional variation inaccordance with the appropriateAustralian Standard.

For concrete panels the standard is AS3850. For other precast concreteelements the standard is AS 3600.

Figure 4.1 shows recommendedtolerances on as-cast concrete panelsand insert location.

Where required tolerances are less thanthe recommended values, the specificrequirements should be clearly stated onthe shop drawings.

4.6 Specification of concrete The concrete specification should be clearlyshown on the shop drawings and includeany special requirements, eg slump,maximum size aggregate, cement content,water-cement ratio and colour.

The specification of the strength of concreteneeds to take into account the flexuralstrength required to develop insert strengthat lifting as well as the requirements for in-service loading, durability and ease ofconstruction.

The concrete strength required at liftingshould be in accordance with the erectiondesign engineer’s specifications. Someguidance on the early-age strength ofnormal-class concrete is given in AS 1379.To obtain adequate concrete strength forearly lifting it may be necessary to specify28-day concrete strengths of 32 MPa orhigher, which should develop a strength of25 MPa at 7 days, the minimum concretestrength for most proprietary brand liftinginserts to achieve the required limit statefactor of 2.5 during lifting. Higher strengthconcrete may be used to enable concretepanels to be lifted earlier than 7 days.

Verification of concrete strength should becarried out by testing in accordance with AS3600 and AS 1012.

Figure 44.1: RRecommended ttolerances

PANELS

Tolerance (mm)

PanelHeight (m) Linear Angular Profile

Width Height Thickness Squareness Twist Warp Straightness of edges(Note 1) (Note 2) (Note 3) and flatness of surfaces

<3 +0,-6 ±3 ±3 ±4 ±3 ±3 ± Length/1000

≥3<6 +0,-6 ±6 ±3 ±5 ±3 ±3 ± Length/1000

≥6<10 +0,-6 ±6 ±3 ±6 ±3 ±3 ± Length/1000

≥10 +0,-6 ±6 ±3 ±8 ±3 ±3 ± Length/1000

INSERT LOCATION

Type of insert Tolerance (mm)

Face lifting ±20

Bracing ±50

Strongback ±5

Edge-lifting

longitudinal ±20

thickness ±5

Fixing ±5

NOTES:

1 Expressed in terms of the distance by which ashorter side of the concrete panel deviates from astraight line perpendicular to the longer side andpassing through the corner of the unit.

2 Per metre width in 3m length.3 Per metre width.

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4.7 Design for manufactureand erection

4.7.1 Design and manufacture

In determining the size and shape ofconcrete elements, consideration shouldbe given to:

• whether concrete elements are to becast on-site or off-site;

• size, capacity and configuration ofcrane(s) available to undertake liftingand erection;

• location and proximity of overheadpower supplies;

• access to and around the site;

• bracing and propping requirements;and

• transport restrictions.

Where concrete elements are to be castoff-site, consideration should be given tolimiting one dimension so that theelement can be transported without theneed for a pilot or special permit.

4.7.2 Additional reinforcement

Additional reinforcement may be requiredin concrete panels and precast concreteelements to accommodate forces duringhandling, transportation and erection.

Additional reinforcement or strongbacksshould be provided where the maximumflexural tensile stress in a concrete panelexceeds the limits recommended in AS3850.

For concrete panels additionalreinforcement may be required:

• near the base of the panel to resiststresses arising from thermal andshrinkage movements whilst thepanel is supported only on thelevelling shims;

• at edges and around openings in thepanel to resist thermal and shrinkagestresses and to prevent cracking dueto panel mishandling; and

• where there is a possibility of loadreversal due to mishandling duringtransport or erection.

4.7.3 Design for erection

When fixed length multi-legged slingsare to be used for lifting concreteelements, any two of the lifting insertsshould be capable of supporting thetotal load.

The load capacity of lifting inserts isdependent on several factors including:

• the concrete strength of the concreteelement at the time of lifting;

• embedment depth of the insert; and

• direction of load, shear or tension(see Figure 4.2).

Figure 44.2: SShear lloads aand ttensionloads iin eedge-lifted cconcrete ppanels

When selecting a lifting insert, ensurethat the nominated capacity from themanufacturer’s catalogue is for thedirections of the load being applied.

All lifting inserts require adequateembedment or anchorage to functioneffectively. Anchorage is affected by:

• proximity to edges;

• proximity to holes, recesses or edgerebates;

Concrete panel

Direction of load before rotation

Concrete panel

Direction of load after rotation

Edge lifter

SHEAR LOAD

TENSION LOADEdge lifter

27

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• proximity to other loaded liftingdevices;

• concrete thickness;

• concrete strength at lifting;

• embedment depth;

• the presence of cracks; and

• the proximity of reinforcement orprestressing tendons.

Horizontal bars placed around the footof a lifting insert may provide very littleadditional lifting capacity to the insert.

Lifting inserts should be configured inaccordance with the manufacturer’srecommendations, including componentreinforcement requirements.

The number of lifting inserts required isdependent on several factors includingthe concrete element size and shape,insert capacity and insert location. Thelocation of lifting inserts is interrelatedwith the reinforcement design and theproposed erection procedures.

When locating lifting inserts, considerationneeds to be given to the need forstrongbacks if the concrete element haslarge or awkwardly located openings.

Multiples of three rows or columns oflifting points where equal loading isrequired should be avoided because ofthe complex rigging configurationsrequired. For example, liftingarrangements comprising 3, 6, 9 or 12lifting points should be avoided.Preferred lifting insert configurations forconcrete panels are shown in Figure 4.3.

Although loads in the slings attached toeach insert in Figure 4.3 are equal, theloads on the inserts may not be equalfor face-lifted concrete panels because ofthe varying inclination of the slings tothe panel which also varies duringrotation of the panel.

In general, the rigging system should bedesigned to distribute equal loads to alllifting points. In some circumstances thedesign may require unequal loading onlifting points causing an increased loadto be applied to particular lifting inserts.This needs to be taken into account inselecting the capacity of these inserts.

Where this is the case, suchrequirements should be clearly specifiedon the shop drawings.

To prevent the concrete panel slewingsideways during erection, lifting insertsshould be located symmetrically aboutthe centre of gravity across the width ofthe panel. In determining the centre ofgravity, the effect of any additionalequipment such as strongbacks needs tobe taken into account. When the panelis lifted, the bottom edge should behorizontal.

Lifting inserts may be positioned in theface or edges of a concrete panel. Theactual locations of the lifting inserts isdetermined according to the:

• method of lifting (face or edge);

• mass, size and shape of the concreteelement and presence of openingsand cut-outs;

• structural capacity of the concreteelement;

• concrete strength at the time oflifting; and

• capacity of the lifting inserts.

When it is intended that concrete panelsbe tilted about an edge using anchorsplaced in the panel face, the geometriccentre of the face-lift inserts must beabove the panel's centre of gravity.

Face-lifted panels should be designed tohang no more than 100 from the vertical.If this is not possible, considerationshould be given to using edge-lifting ora combination of face-lifting and edge-lifting.

Bracing inserts should be located toallow the braces to hang verticallywithout interfering with the liftingrigging. A horizontal displacement of200mm for the bracing insert from thevertical line of the lifting inserts willnormally be adequate.

Bracing inserts should not be locatedcloser than 300mm to the edge of apanel, footing or other bracing support.

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Figure 44.3: PPreferred cconcrete ppanel rrigging cconfigurations

This illustrationhas beenreproduced withpermission fromSAI Global

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4.8 Panel thicknessThe thickness of a concrete panel needs tobe adequate to:

• carry the design loadings;

• limit the lateral deflection of the panelto 1/250 of the panel span underserviceability loadings as required by AS3850; and

• meet the minimum thickness required byAS 3600 for the specified fire resistancelevel (FRL ) where the panel is requiredto have a fire resistance.

4.9 Slenderness effects

4.9.1 Panel height to thickness ratio

Panel height to thickness ratios arespecified in AS 3600. These ratios maybe exceeded provided a detailedanalysis is carried out taking intoaccount the following factors:

• loading on the panel;

• moments due to the eccentricity ofvertical loads;

• moments due to deflection of thepanel and its supports; and

• long term effects, if any.

4.9.2 Dual lift slenderness design

Buckling and instability can occur duringlifting and erection of long slenderconcrete elements.

Lifting inserts should be located toensure that compression flange buckling(as in a long slender beam) cannotoccur particularly during rotation ofconcrete panels.

The span/thickness ratio of the concreteelement between lifting points should belimited to a maximum of 60 (see Figure4.4) unless a detailed buckling analysisis undertaken.

4.10 Panel supportsConcrete panels should be designed to siton only two localized shimming pointswhen initially erected. The panel and thefootings should be designed to carry theforces from the localized supports, takinginto account normal construction tolerances.

By specifying the locations of only twoshimming positions beneath a panel, thedesigner can control where the weight ofthe panel is supported. Constructiontolerances are usually such that multipleshimming will not distribute the panelweight to its support in a predictable

Figure 44.4: PPanel rrotation

Concrete panel

Rigging to tailing hoist

Recommend

ed maxim

um

span/th

ickness

: 60

Thickness

Rigging to main hoist

30

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manner, since any two of the shims arelikely to support most of the load. Aftererecting the panel, grouting beneath thepanel may serve to redistribute loadfollowing settlement beneath the originalshimming points or additional loading ofthe panel.

Where two panels land on a discretesupport, the load eccentricities that occurduring construction, because one panel hasto be erected before the other, cansometimes be a critical load case in design.

See section 9.3 of this code for furtherinformation on shims.

4.11 Fixing insertsThe design of fixing inserts for connectingpanels to roof framing, and other structuralmembers, should comply with AS 3850 andprovide for the following:

• the number, location and placement offixing inserts, adequate to resist thetension and shear forces (static andcyclic) imposed on the connections;

• the reduction of insert capacity whenplaced near an edge or an opening;

• component reinforcement;

• adequate cover to all inserts; and

• ductile behaviour and robustness of thesteel insert.

The type and characteristics of fixing insertsshould be as specified on the shopdrawings and should not be changedwithout prior approval from the projectdesign engineer.

Fixing capacities are reduced when fixingsare placed in near proximity to each otheror near edges and openings. Considerationshould therefore be given to the effects ofinterference with other fixtures, fittings andproximity of openings and edges. In thesecases, consideration should be given toproviding additional reinforcement or othermeans to prevent failure and to resistseparation of the connection.

Extreme heat, such as occurs during a fire,reduces the capacity of fixing inserts andother critical components. Drilled-in insertsmay suffer a greater strength loss due toexposure to fire than cast-in inserts. Fixingsmay have to be protected against fire ifheat will adversely affect their performance.Drilled-in inserts may be used for firesituations provided their performance canbe substantiated.

Care should be taken to ensure thatsecondary effects, for example eccentricityof the steelwork framing cleat and semi-rigid rafter connections, are determined andconsidered in the selection of fixing inserts.

4.12 Joints Joint widths (gaps) between adjacentconcrete elements should be sufficient tomaintain designed position and alignmentduring erection and accommodatetolerances and expected movements.

Unless otherwise specified, joint widthsbetween adjacent concrete elements shouldnot be less than:

• 15 mm for joints with flexible sealant;

• 20 mm for mortar or grouted joints; and

• 150 mm for in-situ concrete infills.

Special care should be taken whenspecifying minimum joint width as the panellocation tolerance, width dimension toleranceand squareness tolerance may significantlyreduce joint widths and affect the choice ofjoint sealant and its performance.

When selecting joint filling materials,consideration needs to be given to:

• thermal and shrinkage movement of theconcrete element;

• fire resistance level;

• weather resistance;

• structural movements to beaccommodated;

• dimensional tolerances of panels; and

• panel location tolerance.

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4.13 Brace footings

4.13.1 General

The ends of braces should be fixed to asolid, flat concrete or other surface thatis capable of resisting the applied loads.

Brace footings need to be designed toresist all expected loads, including:

• construction loads; and

• wind loads for temporary structuresin accordance with AS/NZS1170.2.

Combinations of applied loads shouldcomply with AS/NZS 1170.0.

Requirements and details of bracefootings for each type of concreteelement should be clearly specified onthe shop drawings. This should includethe required concrete strength of thefooting at the time of installation of thebracing.

4.13.2 Floor slabs

Floor slabs are frequently sufficient forbrace footings, however it is unlikelythat floor slabs less than 100mm thickwill provide adequate fixing for braces.It should not be assumed that a slabgreater than 100mm thickness willalways be adequate.

Braces should not be fixed closer than600mm from a joint in the slab.

4.13.3 Concrete blocks (deadman)

Where floor slabs are not capable ofresisting the bracing forces, or are not inplace, concrete blocks (deadman) maybe necessary to use as brace footings.

Unless specifically designated otherwise,the concrete strength of the bracefooting at the time of installation of thebracing should be at least 25 MPa.Brace footings are frequently cast usinglow strength concrete and will need tobe left for longer to ensure anchors donot pull out. The specification of earlyage strength concrete may be necessary.

A sketch of the brace footing should beprovided to the erector by the builderbefore erection commences. The sketchshould be signed by the erection designengineer.

In calculating the capacity of the bracefooting, the direction of the appliedbrace loads, both in compression and intension, needs to be taken into accountto ensure stability under all conditions.Combined vertical and sliding modefailure needs to be considered.

Concrete block brace footings cast in theground will need a larger mass in sandysoils compared to stiff clays which havebetter cohesive properties and are betterable to resist pull out loads.

4.13.4 Other footings

Other types of footings may be usedproviding they are designed to ensuresufficient capacity to resist the forcesfrom the braces. For example, concretepiles may be used as footing

4.14 Connections

4.14.1 General

Concrete elements should be incorporatedinto the structure in such a manner thatthe risk of progressive collapse iseliminated.

Connections should be specified anddetailed on the shop drawings.

A selection of typical panel connectionsfor various situations is shown at Figure4.5.

Impact ddriven ffixings, iincluding eexplosivecharge ddriven ffixings, sshould nnot bbe uused.

4.14.2 Panel to panel

Connections between concrete panelsshould allow for independent shrinkageand thermal movement between panelsand allow for construction tolerances inlocating fixing ferrules and other cast-incomponents.

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Figure 44.5: VVarious ttypical ppanel cconnections

Filler (fire-rated if required)

Filler (fire-rated if required)

Pocket formed in panel andlater filled with grout. Anglemay be surface-mounteddepending on fire requirements

Sealant and backing rod

T-connector plate withelongated holes, boltedto ferrules cast in topedge of wall panels

For maximum tolerance,connecting angle shouldhave horizontal andvertical slotted holes

Angle bolted to anchoredferrules cast in the panels

Panel to panel at T-junction

AT SIDE WALLS AT END WALLS

Member of horizontalwind-load truss weldedor bolted to panels(roof truss seat usessimilar connection)

Member of horizontalwind-load truss weldedor bolted to panels totransfer lateral loads to end walls

Parapet detail

Roof truss with angle seat Purlin seat

Angle bolted to cast-in inserts

Sealant and backing rod

Panel to panel at external corner

Metal capping, packed to aminimum 1 in 4 inward stope

Panel vertical joint seal carriedacross top of panel

Roof flashing

Roof

This illustration hasbeen reproducedfrom the Tilt-upConstruction NotesT50, 1997 withpermission ofCement Concrete &Aggregates AustraliaPanel to roof truss

Parapet detail

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In assessing the requirements forconnections between panels,consideration needs to be given to theeffects of abnormal loads on the building,such as vehicle impacts. For detailedinformation and recommendations onthese issues, refer to the Precast ConcreteHandbook referenced in Appendix C.

4.14.3 Panel to footing or floor slab

A fixing system should be used to resisthorizontal load transmitted fromconcrete panels into footings or floorslabs. The fixings should be capable ofresisting the forces set out in AS 3850.Friction forces should not be assumed toresist any part of this force.

Grout tubes, particularly in the edges ofthin panels, should be provided withrestraining reinforcement on each side ofthe tube.

4.14.4 Panel to structural steel

Connections between concrete panelsand other structural members, need tobe designed to resist the lateral andvertical forces imposed on theconnections in accordance with therequirements of AS 3850 and AS 3600,as appropriate.

The design of the connections needs totake into account the capacity of boththe fixing and the concrete. The ultimatecapacity should be the lesser of fixingfailure in tension and/or shear, orconcrete cone failure.

The project design engineer shouldmake allowance in the design ofconnections between concrete panelsand steelwork for unexpected loads.These loads may result from:

• erection problems due to paneltolerance or fabrication issues;

Figure 44.5: VVarious ttypical ppanel cconnections ((continued)

Dowel holes in panel filled withflowable grout as well as recessbetween panel and slab edge

Panel placed and levelled onshims before fully bedding on dry-pack mortar

Hole drilled and dowel epoxy-groutedin place (This permits accurate setting-out after slab and footing is cast)

Sealant

Continuous recess with roughenedsurface for bond (may be eliminatedif tie-bars designed to carry shear)

Threaded tie-bars screwed intoferrules cast in wall panel

Concrete or steel permanent formwork

Bearing pad (50-mm wide typical)

Panel to supended insitu concrete floorPanel to footing slab

Panel placed and levelled on shimsand temporarilly held by boltingthrough angle into cast-in ferrule,or by ‘blocking’

Threaded bars are screwed intoferrules cast in panel, prior toplacing floor stabs, as final fixing

Angle fixed to footing withexpanding anchor.(Alternatively, panel may be‘blocked’ on either side)

Panel to strip/pad footing

Concrete topping to precast unitsif required

Precast concrete floor units

Bearing pad (70-mm wide typical)

Continuous-angle seat, site-welded toplates cast in wall panel

Panel to suspended precast concrete floor

This illustration hasbeen reproducedfrom the Tilt-upConstruction NotesT50, 1997 withpermission ofCement Concrete &Aggregates Australia

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• steelwork collapse due to erectionproblems or crane collision; and

• roof steelwork collapse due to fire.

The unexpected loads are generallyadditional tension loads, which tend topull the panel and roof steelwork apart.The loads are generally not those loadsidentified as part of the structuralanalysis.

All concrete panel to steelworkconnections should be designed toensure a ductile failure.

See section 9.2 of this code regardingloads resulting from erection ofsteelwork.

4.15 Strongbacks When strongbacks are required they shouldbe designed to ensure the strongback issufficiently stiff to prevent cracking of theconcrete panel due to differential deflection.

The location of the strongbacks should notinterfere with the rigging at all angles ofpanel rotation. See Figure 4.6 for examplesof strongback applications using steelchannel section.

The erection design engineer shouldapprove any changes to the specifiedstrongback system prior to the changesbeing carried out and the shop drawingsamended accordingly.

Figure 44.6: SStrongbacks

This illustrationhas beenreproduced withpermission fromSAI Global

(a) Examples of strongback applications

(b) Steel strongback

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5PartDocumentation

C O N T E N T S

PAGE

5.1 Structural design drawings .................................... 36

5.2 Panel documentation ............................................. 365.2.1 Marking plan ............................................... 365.2.2 Shop drawings ............................................ 365.2.3 Erection documentation .............................. 37

5.3 Lodgement of shop drawings with local government.................................................... 37

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5.1 Structural designdrawings Structural design drawings and details arethe responsibility of the project designengineer and should provide sufficientinformation for the preparation of shopdrawings by the shop detailer and erectiondocumentation by the erection designengineer.

The information provided on structuraldrawings should include:

• date and issue number of the drawing;

• plans and elevations clearly indicatingthe structural framing and concreteelement layout;

• structurally critical dimensions;

• reinforcement and concrete coverrequired for in-service loads andconditions;

• framing connection locations andrequired type (eg cast-in) and thecapacity of the fixing inserts;

• levelling pad details;

• structural design criteria affectingconstruction, eg wind design loads,tolerances;

• the concrete specification including allspecial requirements to meet in-serviceloadings and conditions and a note thatall concrete must meet the strengthrequirements at the time of liftingnominated on the panel shop drawings;

• base connection details, eg groutingsequence of dowel connections; and

• location of services such as plumbing,electrical and cabling conduits.

5.2 Panel documentation Concrete panel documentation consists of amarking plan, shop drawings and erectiondocumentation for the concrete elements.Panel documentation should be available atthe site whenever work is carried out.

5.2.1 Marking plan

A marking plan (layout plan) preparedby the shop detailer should show thelocation of each concrete element.

5.2.2 Shop drawings

Shop drawings should provide allinformation and details required tomanufacture the concrete element.

The builder should check the shopdrawings for compliance withdimensions of structural drawings.

Standardised symbols should be usedon the drawings in accordance withthose used in AS 3850.

Shop drawings should include thefollowing:

• date and issue number of thedrawing;

• project location;

• concrete element number;

• the mass of each concrete element;

• concrete element dimensions andcentre of gravity;

• structural reinforcement and concretecover dimensions;

• the size, configuration and concretecover of any additional reinforcementrequired for the transport and liftingof the concrete element;

• the location, orientation and depth ofall inserts and the size, configurationand concrete cover of any componentreinforcement that is required. Alledge-lift inserts and some other insertsrequire component reinforcement anddetails should be obtained from thesuppliers of these items;

• location of any conduits forplumbing, electrical or cabling;

• location of grouting ducts and, whererequired, lateral restraint details;

Documentation

37

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• the type, make, capacity andtechnical specifications of:

- lifting inserts;

- bracing inserts and fixings;

- fixing inserts; and, if required

- strongbacks, strong back fixinginserts and locations;

• the class and strength gradedesignation of the concrete asdefined in AS 3600;

• the required concrete compressivestrength of the element, bracingfootings and prop footings (if required)as applicable at the time of lifting anderecting. Concrete strength gradeshigher than that specified on thestructural drawings may be necessaryto achieve the concrete strengthsrequired at the time of lifting;

• the surface finish of each concreteelement;

• where appropriate, the tolerancelimits on the concrete element (seesection 4.5.3 of this code);

• the orientation (position relative toeach other) of the concrete elements:and

• rigging details.

The shop drawings should be signedand dated by the project designengineer and the erection designengineer. A sample shop drawing,illustrating some detail, is shown atAppendix B.

Before being made available on site,shop drawings should be subject to anapproval process whereby they arereviewed by the project design engineer,erection design engineer and buildingdesigner. Any necessary amendmentsshould be marked up and returned tothe shop detailer for incorporation intothe shop drawings. These amendeddrawings are the approved shopdrawings which should be available onsite. See section 1.3.2 of this code.

5.2.3 Erection documentation

Documentation should be provided andsigned by the erection design engineerwhich shows:

• rigging details, including slinglengths;

• configuration and size of erectionbraces and, where applicable, kneebraces and cross-bracing;

• propping details if required;

• requirements for erection bracefootings (and prop footings ifrequired), brace fixings and concretestrength of the footings at time oferection; and

• levelling pad details.

In situations where the rigging differsfrom a configuration shown at Figure4.3, the rigger should prepare a riggingdiagram detailing the requiredconfiguration with sling lengths,spreader/lifting beam requirements andarrangement of sheaves.

5.3 Lodgement of shopdrawings with localgovernmentA copy of the approved shop drawingsshould be lodged with the relevant localgovernment authority for filing with therelevant building licence.

Information contained in the shop drawingswill assist in the consideration of any futuremodification work and the safety of anyfuture demolition of the building. TheDepartment of Local Government andRegional Development intends to make thislodgement a requirement of the BuildingRegulations 1989.

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6C O N T E N T S

PAGE

6.1 General ................................................................... 39

6.2 Preplanning and layout.......................................... 39

6.3 Casting bed ............................................................ 39

6.4 Formwork................................................................ 40

6.5 Tolerances .............................................................. 40

6.6 Reinforcement ......................................................... 41

6.7 Manufacturer’s statement and inspection .............. 41

6.8 Placement and compaction of concrete ................. 41

6.9 Curing and release agents...................................... 41

6.10 Lifting, bracing and fixing inserts .......................... 42

6.11 Element identification............................................. 42

6.12 Stripping and repair ............................................... 42

PartCasting

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6.1 General Concrete elements should be manufactured inaccordance with the approved shop drawings.

6.2 Preplanning and layoutPrior to manufacturing the concreteelements, the parties involved in thedesign, manufacture, transport and erectionprocess should have planned the completeconstruction and erection sequences.

The casting and erection sequences of theconcrete elements should be agreed betweenthe builder and erector. The builder, inassociation with the erector, should prepareplans showing the erection sequence andbracing layout in accordance with therequirements of section 8.2 of this code.

For concrete panels cast on site, the floorslab is commonly used as the casting bedand crane standing area.

Prior to the casting bed being set out,consideration should be given to thefollowing:

• the orientation of the panels on thecasting bed;

• vehicular access to and around the site;

• location of overhead power lines, utilitytrenches and other services;

• panel storage locations, where required;

• crane type, size and lifting position; and

• erection sequence and bracing layout.

When assessing crane requirements, notethat:

• a crane’s maximum capacity refers to itscapacity at minimum radius and oftenbears little relation to its actual capacityto lift large concrete panels intoposition;

• the selection of crane size needs to bemade with consideration of themaximum working radius and load frompick up to final positioning;

• for face-lifted concrete panels,assessment of the true working radius ofthe crane should be made by adding atleast 1.5 metres to the final panelposition radius. (See section 8.6 andFigure 6.1); and

• usually the crane will be set up such thatit does not need to slew greater than180 degrees and the lifting radius isallowed for over that area. The slewingradius of the crane counterweightsshould not be overlooked in relation toany braces installed after crane set up.

For concrete panels, the casting sequenceshould reflect the erection sequence. Toavoid multiple handling with stack-castconcrete panels, the top panel should beerected first.

6.3 Casting bedCasting beds need to be capable ofsupporting formwork, panels and otherloads, particularly where the casting bed isused as the crane standing area. Thebuilder should obtain verification from theproject design engineer that the casting bedcan carry the construction loads.

The surface of the casting bed should beappropriate for the surface finish of theconcrete element specified on the shopdrawings.

Any cracks and defects in the casting bedmay reflect in the cast panels. Where thereis insufficient room to cast all panels on thecasting bed, panels may be cast one on topof another, in reverse order of erection.Care is needed with this casting method tolimit the tolerances of a panel, especiallyflatness, as the deviation may becumulative as successive panels are castone on top of another.

Additional casting beds may be constructedas required.

Panels are usually cast with their externalface down to minimise the need for externalpatching after erection.

Casting

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6.4 Formwork Formwork should be designed andconstructed in accordance with AS 3610 andthe requirements of section 6.5 of this code.

See section 6.7 regarding the writteninspection report required before casting ofconcrete panels is carried out.

Tilt-up and precast concrete constructionusually requires multiple use and earlystripping of formwork. These requirementsshould be taken into account in the designof the formwork.

Formwork design for concrete elements canhave a direct bearing on how concreteelements are cast and handled and on theloads imposed during manufacture. Inparticular, the following should be noted:

• suction on flat mould surfaces isincreased by the presence of water.Suction pressure can be relieved by liftinggently at one end or edge of the element;

• friction forces are increased by verticalor near vertical sides on a mould. Toreduce friction, mould sides should bedetailed with adequate draw, or shouldbe released to allow them to springback. To avoid overloading liftinginserts, the mould can be vibrated whilegently lifting one end of the concreteelement; and

• both suction and friction can be reducedby the use of good quality mouldrelease compounds.

These matters were discussed in section4.3.2 of this code.

6.5 Tolerances The tolerance on deviation from flatness ofthe casting bed should be such that the as-cast element meets the requirements ofsection 4.5.3 of this code.

The visual impact of element misalignmentmay be reduced by the use of variousdetails such as chamfers and arrises.

Figure 66.1: CCrane llifting rradius

This illustrationhas beenreproduced withpermission fromSAI Global

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6.6 ReinforcementReinforcement needs to comply with therequirements of AS 3600 and the approvedshop drawings.

Reinforcement should be securely fixed andsupported in the correct position to preventdisplacement during concrete placement.Where plastic tipped metal bar chairs areused to support reinforcement in externalwall panels, care should be taken to ensurethat the plastic tips are not damaged duringor after casting.

6.7 Manufacturer’sstatement and inspectionPrior to placing concrete, the formarrangement and set up should beinspected for compliance with the shopdrawings. In particular, this should includechecks on:

• formwork dimensions;

• formwork stability;

• panel edge details and penetrations;

• connection details;

• insert locations, types and fixing toreinforcement;

• reinforcement size, location, concretecover and fixing; and

• bond-breaker effectiveness.

The inspection should be carried out by acompetent person who was not directlyinvolved in the original assembly of theformwork, reinforcement and hardwarecomponents. For stack casting, aninspection should be done prior to thecasting of each panel.

For concrete panels cast on or off-site,regulation 3.88G requires a written report ofthis inspection to be kept at the sitewhenever tilt-up work is being carried out.

Prior to the transportation or erection ofconcrete elements, the builder shouldprovide to the erector a statement signedby the manufacturer stating that themanufacture of the elements was carriedout in accordance with the engineerapproved shop drawings. For site castingthis statement should be signed by acompetent person.

The manufacturer's signed statement shouldbe available on site at the time of liftingthe elements listed on the statement. Seesection 6.11 of this code for elementidentification.

No lifting should take place until the signedstatement covering the particular element isavailable on site.

The statement should contain as aminimum the information contained in theform at Appendix B.

Records should be kept to substantiate themanufacturer’s statement.

6.8 Placement andcompaction of concrete Prior to placing concrete, release agenteffectiveness should be checked bysprinkling water over the casting bed. If therelease agent is effective, the water shouldform into beads.

The concrete supplier should be advised of:

• the specified characteristic concretecompressive strength;

• the concrete compressive strengthrequired at time of lifting;

• the required maximum aggregate size;

• the required slump;

• special design requirements, if any, egcement content, water-cement ratio andcolour; and

• the site access, required rate of supplyand the method of placement, eg typeof pump.

Concrete should be placed in a uniformmanner and evenly spread over the areabefore commencing compaction. Vibratorsshould be used to compact the concrete.Particular attention and care needs to bepaid to vibrating the concrete around theinserts and adjacent to corners and edges.

6.9 Curing and release agentsThe curing compound and release agentshould be applied in accordance with themanufacturer’s specification and therequirements of section 3.3 of this code.Regulation 3.88G

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6.10 Lifting, bracing andfixing inserts Variations should not be made to thespecified insert locations on the approvedshop drawings without the written approvalof the erection design engineer. If changesare made, the shop drawings should beamended accordingly.

All cast-in inserts and any componentreinforcement should be accuratelypositioned and securely fastened inaccordance with the supplier'srecommendations, and as detailed on theshop drawings, to prevent dislodgementduring concrete placement.

Inserts should not be welded toreinforcement.

6.11 Element identification All concrete elements should bepermanently marked during or immediatelyafter manufacture with a uniqueidentification designation, commonly theconcrete element number, and date ofcasting.

6.12 Stripping and repair Formwork should be carefully stripped andstored to prevent damage.

If the concrete element suffers damagegreater than minor spalling, the proposedrepair system should be approved in writingby the project design engineer before beingcarried out.

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C O N T E N T S

PAGE

7.1 General 44

7.2 Handling and storage of site-cast concrete panels 44

7.3 Handling and storage of factory manufactured concrete elements 44

7.4 Transport 46

7.4.1 General 46

7.4.2 Preplanning 46

7.4.3 Loading 46

7.4.4 Support frames 46

7.4.5 Element protection 47

7.4.6 Delivery 47

7PartHandling, storage and transport

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7.1 General Methods for handling and storage ofconcrete elements will vary depending onthe type of element and whether theconcrete element is cast on-site or off-site.

Concrete panels cast on site should only bestored in a designated area and in such amanner as to minimise multiple handling.

There is always a risk to safety of personsinvolved and a risk of damage to aconcrete panel every time it is moved.Careful planning and scheduling willminimise the need to relocate panels. Apanel should not be relocated without firstdiscussing the need with an engineer.

Factory manufactured concrete panels andother concrete elements should be retainedin the precast yard and delivered to site forinstallation as required.

The rigging system to be used for eachconcrete element must be as set out in theerection documentation detailed in section5.2.3 of this code.

Concrete elements should not be liftedwithout the appropriate methods beingdocumented.

7.2 Handling and storage ofsite-cast concrete panelsWhere storage of site-cast concrete panelsis required the storage area should be:

• well drained and consolidated;

• located where there is little chance ofdamage to the panels to be stored;

• adequate to support the weight of thepanels and any necessary stackingframes; and

• unlikely to settle unevenly.

The storage area needs to provide adequateroom for lifting equipment and formanoeuvring trucks (if required) and cranes.

Racking systems, frames and supports forpanels should be constructed in accordancewith a design prepared by an engineer.

The general requirements for handling andstorage of concrete panels on site are asfollows:

• panels should only be stored in aposition approved by the erection designengineer. Panels should preferably bestored in the vertical position;

• ground conditions need to be checkedby an engineer to ensure that the massof the element and any necessarystacking frames can be supported; and

• where a panel is to be storedhorizontally or on a suspended floorslab, approval and written instructionsshould be obtained from the projectdesign engineer before proceeding.

Where edge-lifted panels are storedhorizontally, they should be placed asoriginally cast to ensure that componentreinforcement around edge lifting inserts iscorrectly oriented for re-lifting.

Where panels are stored in areas of vehicularmovement, protection by way of bollards orother physical barriers and appropriatewarning signs should be considered.

During handling and storage, care shouldbe taken to minimise the likelihood ofimpact between the concrete panels.

7.3 Handling and storage offactory manufactured concreteelementsRecommended practices and procedures forhandling and storage of precast concreteelements can be found in the PrecastConcrete Handbook referenced in Appendix C.

With proper preplanning and discussion ofdelivery arrangements between the builderand precaster, handling of factorymanufactured concrete elements can beminimised.

Precast concrete elements are usuallystored horizontally, however wall claddingpanels are usually stored vertically by usingA frames or a racking system.

Handling, storage and transport

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For horizontally stored concrete elements,only two points of support should be usedif possible, located to minimise stresses onthe element. If more than two supports arenecessary, care should be taken to ensurethe concrete element does not bridge overone of the supports.

General guidelines for handling and storingprecast concrete elements are as follows:

• wherever possible, elements should bestacked at only two support positions,one fifth of the length of the elementfrom each end for wall units;

• support points should be directly aboveeach other, not misaligned;

• stacked elements should be of equallength;

• softwood supports should be used toreduce edge chipping and minimisestaining. Hardwood supports may causestaining of concrete which may bedifficult to remove; and

• storage should be planned to minimisehandling before delivery.

See Figure 7.1 for correct horizontalstacking of concrete panels.

Figure 77.1: HHorizontal sstacking oof ffactory mmanufactured cconcrete ppanels

Units should be stacked with suitablepackings, near ends for beam and slabunits and at L/5 from ends for wall units

DO NOT use misaligned packers DO NOT use more thantwo support points

DO NOT place shorter unitson longer ones

DO NOT place longer unitson shorter ones

This illustration hasbeen reproduced fromthe “Precast ConcreteHandbook” withpermission from theNational PrecastConcrete AssociationAustralia.

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7.4 Transport

7.4.1 General

To reduce hazards, the transport ofconcrete panels should be avoidedwherever possible. Preplanning willreduce the need to transport concretepanels around the site.

7.4.2 Preplanning

The following points should be takeninto account when transporting concreteelements and whenever it is necessaryfor concrete panels to be transported toor around the site:

• the shape, size and mass of theconcrete elements;

• specific design requirements,including the concrete strengthrequired for transportation and thestability of long or unusually shapedpanels during transportation. Theprecaster needs to ensure theconcrete element has reached thedesign concrete strength prior totransportation;

• traffic regulations governingmaximum weight, length, width andheight of the laden vehicle;

• all-weather access for the deliveryvehicle and the traffic managementplan referred to in section7.4.6 ofthis code;

• capacity of any permanent structuresto carry transport loads; and

• temporary storage, where required.

7.4.3 Loading

The concrete elements should be loadedin a sequence compatible with therequired unloading sequence on site.

Secure restraint of loads on vehicles isimportant in preventing accidents andinjuries. Load restraints may be chainsor webbing straps.

The adequacy of a particular method ofrestraint will depend on the type ofconcrete element being transported andthe type of vehicle being used.

The precaster should advise thetransporter of any special requirementsfor support and restraint of the concreteelements.

Special restraints may be required forlong concrete elements, especially whentransporting over long distances.

The equipment should be inspectedbefore use to ensure it is serviceable.

Concrete elements should be loaded sothat identification marks are visible priorto and during unloading.

The location of lifting inserts on theconcrete elements should be checked toensure they are compatible with thelifting system used. Lifting inserts shouldbe clearly identified to assist in theloading and unloading stages.

The transporter needs to ensure thatdrivers have been adequately instructedin the safe transportation of theconcrete elements, with particularattention given to:

• power lines;

• recognised truck routes for over-dimensional loads; and

• roundabouts and reverse camber inthe roads.

Differential road cambers may inducetorsional loads in long panels. Slenderconcrete panels may require temporarystiffening against lateral buckling.

The transporter should be responsible forobtaining the permit for all overdimensional loads. Drivers should beable to produce the permit upon request.

Drivers should stop and check the loadand the restraints shortly aftercommencing the journey. Restraints tendto loosen due to settling of the loadand stretch of the restraints, particularlyif webbing straps are used.

7.4.4 Support frames

Frames used to support concreteelements during transport need to bedesigned to withstand loads and forcesacting on the system during loading,transportation and unloading.

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A frame system that is not an integralpart of the transport vehicle or trailershould be adequately secured andcapable of withstanding any forcesapplied during loading, transportationand unloading.

Particular care needs to be taken duringloading and unloading concrete elementsfrom frames to ensure the frames remainstable at all stages.

7.4.5 Element protection

Points of contact between concreteelements, supports, and restraintsshould be provided with protectivematerial to prevent breakage andstaining. Corner protectors should beused under all restraints to preventmovement and damage to the concreteelement.

Low friction material should not be usedas packing between concrete elementsand supports.

Where concrete elements are transportedhorizontally, they should be stacked sothat each element can support the loadsfrom above. The support points shouldbe directly above each other unlessspecifically designed otherwise.

The stacked height of concrete elementsshould be limited to ensure that thebearers and lowest elements cansupport the loads from above and thatthe stack remains stable duringtransportation.

Particular attention needs to be given toprestressed concrete elements to ensurethey are only supported at designatedbearing points and that restraint systemsdo not impose excessive loads.Prestressed concrete elements shouldnot be supported, even temporarily, atany other points and they should not betipped sideways.

7.4.6 Delivery

Delivery of concrete elements onto thesite requires co-operation between thebuilder, precaster, transporter anderector.

The builder should provide a documentedtraffic control management plan thatincludes, where necessary, trafficcontroller, barricades and road closurepermits to allow unimpeded access to thesite. This traffic management plan shouldform part of the work plan which must beavailable on site at all times when workis carried out.

The precaster needs to ensure that thetransporter has detailed instructions onhow to enter the site.

The transporter should inspect the siteprior to entry to verify there are nodangers such as uncompacted backfilledexcavations or overhead services. Thearea to receive the delivery vehicleshould be firm and, where possible, level.

The transporter should position thevehicle as directed by the erector andstabilise the vehicle prior to releasingthe concrete element restraints. Wherepossible, semi-trailers should bestabilised by lowering the support legsonto a firm base. The transporter needsto be aware of which elements are to beunloaded first.

The builder needs to ensure that the areawhere the crane is to be set up is stable,compacted if on the ground, and able tosupport the crane when loaded andpositioning concrete elements in theirstorage or erection positions. The craneoperator should check these factors withthe builder prior to handling any concreteelements. See section 8.5 of this code.

If the unloading sequence can lead toinstability of loads, the concreteelements should be individually secured.Individual elements should not bereleased until the crane has taken theinitial load of that element.

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C O N T E N T S

PAGE

8.1 General ......................................................................... 49

8.2 Planning the construction and erection sequence ...... 49

8.3 Work method statement .............................................. 50

8.4 Exclusion zones............................................................ 51

8.5 Crane standing area ..................................................... 51

8.6 Planning cranage requirements ................................... 51

8.7 Operating near overhead power lines ......................... 53

8.8 Operating near braces and panels .............................. 55

8.9 Working at height ........................................................ 56

8.10 Strongbacks.................................................................. 57

8.11 Erection crew................................................................ 57

8.12 Rigging.......................................................................... 57

8.13 Erection of concrete panels ......................................... 58

8.14 Modifications ................................................................ 59

8PartErection to temporarybraced condition

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8.1 General Safe erection of concrete panels and precastconcrete elements depends on thepreplanning process. All personnel should beaware that erection of these elements ispotentially hazardous and the purpose of thepre-planning process is to identify hazardsand control any risk in the erection process.

The aactual llifting oof cconcrete ppanels iis tthetime wwhen ppotential ffor sserious aaccident iishighest.

Due to their large surface area and mass agreat deal of care needs to be taken whenlifting, moving and securing concrete panelsinto position. The likelihood of fatalities if apanel falls over is considerable. Increasingthe risk is the fact that the crane may fallover and other panels that are struck bythe crane or falling panel are also likely tocollapse. With these factors in mind it isextremely important that both the panelerection crew and crane operator are highlyskilled and experienced in the erection ofconcrete panels.

Requirements for training and supervisionare set out in section 2.2 of this code.

8.2 Planning the constructionand erection sequence Prior to erecting concrete elements, thebuilder, in association with the erector,should have planned the completeconstruction and erection sequences.

The planning process should take intoaccount:

• site limitations and local street access;

• concrete element sizes;

• crane size configuration, mobility andaccess;

• compaction of site surface areas;

• casting sequence;

• overhead obstructions, particularlyoverhead power lines and constructionsite overhead power;

• underground power lines and otherservices; and

• underground tanks and soakwells.

A crane layout drawing should be preparedshowing the working radius of the crane.

The planning process should ensure the on-site provision of:

• supervision;

• induction training;

• adequate first aid facilities, workplaceamenities and personal protectiveclothing and equipment in accordancewith the Commission for OccupationalSafety and Health code of practice onthe provision of these services andequipment as appropriate;

• perimeter fencing around the site toprevent access by members of thepublic. Link mesh fencing 1.8 metreshigh will generally be required toprovide sufficient public protection.Other forms of protection may besuitable in some situations;

• adequate access for the type ofconstruction methods to be employed;

• adequate access for the size of thecrane to be used;

• adequate access for semi-trailers andtransport equipment;

• height access equipment appropriate tothe construction methods;

• access to approved shop drawings; and

• risk assessment giving particularattention to overhead power lines at oradjacent to the site.

The rigging system needs to be designed tosuit the spacing and layout of the liftinginserts. See Figure 4.3 for preferred riggingconfigurations.

Sling llengths aare ccritical wwhere tthe rriggingsystem iincludes tthe uuse oof sspreader bbeamsor llifting bbeams wwith sslings rrunning tthroughsheaves.

Erection to temporarybraced condition

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Before erection commences, the builder anderector should:

• confirm that the erector's risk assessmentis appropriate and has dealt with allaspects of the erection procedure,including appropriate exclusion zones;(see section 8.4 of this code)

• make sure that crane and truck access isinspected and confirmed as safe;

• inspect the crane standing area andconfirm that it is safe. Obtain verificationfrom an engineer that the crane standingarea can safely support the erectionloads; (see section 8.5 of this code)

• make sure the crane operating area hasbeen cleared to provide adequate roomfor crane outriggers, counterweight tailswing, boom swing and under-hook andoverhead obstructions, includingoverhead power lines. Refer to section8.6 of this code for points to beconsidered in planning cranagerequirements;

• ensure that provision has been made forsafe working at heights, if necessary;(see section 8.9 of this code)

• confirm the erection crew members areproperly certificated and trained andavailable in adequate number; (seesection 8.11 of this code)

• verify that the element concrete (andbrace footing concrete) has attained thespecified strength for lifting andnominated brace fixing bolts areavailable on site. If the element concretedoes not achieve the specified strengthfor lifting in accordance with therequirements of section 3.2 of this code,the erection design engineer should benotified before lifting occurs;

• check that strongbacks, if required, areavailable and are correctly installed;

• make sure that locating dowels or otherhorizontal restraints are fitted prior tolowering concrete elements and levellingshims are correctly located;

• confirm that the means of support,including falsework, is adequate for theintended purpose and is correctly located;

• check that sufficient clear space isavailable for the safe propping of precastconcrete elements or bracing of concrete

panels and ensure that nominated bracesare fitted to the panels;

• in consultation with the rigger:

- determine if load distribution on liftingpoints is satisfactory;

- ensure that the appropriate riggingequipment is available and isserviceable;

- ensure that braces do not interferewith the rigging;

- check that lifting inserts are compatiblewith lifting clutches and are in theircorrect location and that recesses arecleaned out in preparation for lifting;

- determine an appropriate interval forchecking the condition of braces, andtorque on brace bolts, to ensure theyhave not become loose; and

• determine if weather conditions areadequate for erection.

8.3 Work method statement A work method statement should beprepared, usually by the erector, inconsultation with the builder and the Safetyand Health Representative (if any) of theworkers. In the absence of a Safety andHealth Representative, the work methodstatement should be prepared in consultationwith the erection crew and reviewed by theSafety and Health Representative (if any)following their election.

The work method statement needs to bespecific to the project and based on thedocumentation detailed in Part 5 of thiscode. It should be signed off by the builderand erector. The work method statementshould provide a general description of theerection process, identifying the objectivesof the erection process and broadlydescribing how these objectives are to berealised. Most importantly it should set outthe safe working procedures to be usedduring the erection process.

Sample documents for erection of concreteelements are provided at Appendix B.Sample documents for casting of concreteelements and incorporation of structuralsteel into the final structure are alsoprovided at Appendix B. These documentsinclude schedules for the concrete elements.

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8.4 Exclusion zonesRegulation 4.53 requires, as far aspracticable, that loads are not suspendedover, or travel over, a person.

Only persons directly involved with thelifting of concrete elements should belocated in an area where the lifting istaking place. Such persons should avoidbeing in a position where they could bestruck in the event of a concrete elementfalling or a crane or panel falling over.

Under section 21(1)(b) of the Act, employersand self-employed persons must, as far as ispracticable, ensure that the safety andhealth of non-employees, including membersof the public, is not adversely affected bytheir work or the work of their employees.

In addition, persons having control of aworkplace have a responsibility under theAct (section 22(1)) to take all practicablemeasures to ensure that people who arenot employees who are at the workplace, orlikely to be at the workplace in the courseof their work, or enter or leave theworkplace, are not exposed to hazards.

To satisfy these legislative responsibilitiesexclusion zones should be set up toprevent, as far as practicable, unauthorisedpersons gaining access to areas wherelifting of concrete elements or other itemsis taking place.

This may necessitate the erection of para-webbing, signage and/or fencing dependingon the ease of access and the likelypresence of workers or members of thepublic. All members of the public andworkers not involved in the lifting ofconcrete elements or other items should beprevented, as far as practicable, fromaccessing an exclusion zone while lifting istaking place. The provision of perimeterfencing around the site will assist theoperation of exclusion zones.

Where a common boundary between twoproperties is located in an exclusion zone,an effective means of communication withoccupiers is essential to keep members ofthe public away from the exclusion zonewhile lifting is taking place. This issueshould be addressed in the planning stage(see section 8.2 of this code).

Where a footpath, road or other access wayis located in an exclusion zone, members of

the public and traffic should be prevented,as far as practicable, from passing throughthe zone while concrete elements or otheritems are being lifted and prior to securingconcrete panels with braces.

8.5 Crane standing areaBefore erection commences, the buildershould supply the erector with writtenverification from an engineer that the cranestanding area (floor slab, suspended slab orsurrounding ground, etc.) can safely carrythe construction and erection loads.

The project design engineer should providethis verification where the crane standingarea forms part of the structure.

If the crane is to be set up on the ground,compaction tests should be taken of thearea to ensure the loads imposed by thecrane can be supported.

Backfilled excavations, trenches andsoakwells should be identified andassessed. Additional measures, such as theprovision of timber mats, may need to betaken to ensure that any backfilling cansupport the construction and erection loads.

8.6 Planning cranagerequirements Cranage planning should commence asearly as possible in development of theproject.

The requirements for cranes should be inaccordance with section 3.8 of this code.

It is essential to ensure all lifts can becarried out while keeping a safe distancefrom power lines and obstructions, neveroperating over any person, road traffic,unprotected public space, unprotected siteoffices or amenities sheds.

In accordance with the requirements ofregulation 4.54, cranes and elevating workplatforms (EWP) must be maintained,inspected and operated in accordance withthe written instructions of the designer ormanufacturer of the crane. If it is notpracticable to obtain these instructions theWorkSafe Western Australia Commissionermay approve written instructions. If it is notpracticble for the person in charge of theworkplace to get either of these forms of

Regulation 4.54

Regulation 4.53

The Act, section21(1)(b)

The Act, section22(1)

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instruction then the requirements of AS2550.1 and AS 1418.1 should be followed,together with the requirements of any otherpart of AS/NZS 2550 and AS/NZS 1418 thatare relevant.

The selection of an appropriate mobilecrane, preparation of the site and correctlocation of the crane are crucial in ensuringthe safe erection of concrete elements.Mobile cranes used for this type ofconstruction are often required to workclose to their maximum capacity with highluff angles due to the large size and massof concrete panels. These factors increasethe likelihood of the crane overturning,particularly if the ground is not level. Allcranes used for the lifting and erection ofconcrete elements should be fitted with loadindicators as described in regulation 3.23.

The crane should be located withconsideration given to the erectionsequence of the concrete elements to avoidany possibility of the rear of the craneslewing into braces supporting previouslyerected concrete panels.

Where two or more cranes are operatingthey should be sited so as to prevent themoperating in each other’s airspace.

At appropriate stages, the planning processneeds to consider:

• crane selection, access and siting inaccordance with AS 2550;

• ground support conditions and thelocation of any excavations orunderground services likely to beadversely affected by imposed crane loads;

• proximity of overhead power lines;

• written procedures for setting up anddismantling the crane and the liftingmethod as well as a risk assessment ofthese procedures;

• the make-up of the crane crewappropriate to the particularcircumstances of the job;

• the communication system;

• selection of lifting gear includingappropriate snatch block for rotation ofpanels while suspended if rotation is tobe carried out (see section 3.8 of thiscode);

• personal protective equipment for therigging crew;

• emergency procedures; and

• protection of the public.

The mmaximum rrated ccapacity oor WWLL oof aacrane rrefers tto iits mmaximum lload ccapacityat tthe mminimum rradius. TThis mmust nnot bbeconfused wwith iits aactual ccapacity aat wworkingradius wwhen llifting.

As a general “rule of thumb”, cranes usedon tilt-up work should have a maximumcapacity of at least three times the weightof the heaviest concrete panel to be lifted.In some situations a smaller crane will beacceptable and in some situations a largercrane may be required where largeirregularly shaped elements are to be liftedor where the crane cannot be positionedclose to the casting bed or final position ofthe panels.

Larger cranes are generally more difficult tomanoeuvre around the site. However sitemovements may be minimised with largecranes. Of utmost importance is the need toensure the crane does not damage thestructure or braces when operating,especially slewing.

The extra cost of a large crane may bejustified by a shorter overall erection time.

For all face-lifted concrete panels, the trueworking radius of the crane needs to includean allowance of at least 1.5 metres over theradius to the panel's final position to takeaccount of the hang of the panel from thelifting inserts and any lifting beams, etc.(see Figure 6.1). This may need to beincreased for tall panels. An assessment ofthe true working radius should be madeaccording to individual panel details.

Where lifting is not possible with one craneand it is necessary to use two cranes to"dual lift" concrete elements, the requiredcrane capacities should be carefully assessed.In accordance with regulation 4.54 the ratedcapacity of each crane must exceed thecrane’s share of the load by at least 20%.

Dual lifting is a potentially dangerousoperation requiring a great deal of skill byoperators. Regulation 4.54 requires thatdual lifting only be carried out where thephysical dimensions and mass of the loadprevent the load from being handled by asingle crane that is readily available. Theregulation also requires direct supervision

Regulation 3.23

Regulation 4.54

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by a competent person not otherwiseinvolved in the operation.

Dual lifting should never be carried outwhere wind speeds exceed those specifiedby the crane manufacturer.

“Blind” lifting, where the rigging is on theside of the concrete panel opposite to thecrane, should be avoided because the craneoperator and rigger will be unable tovisually check the rigging during lifting. Veryimportantly, if failure should occur, thepanel will fall towards the crane. “Blind”lifting may be unavoidable in somesituations such as when placing a closurepanel in a building.

8.7 Operating near overheadpower linesWherever plant is required to work nearoverhead power lines a severe hazard iscreated. This occurs in many types ofconstruction activity.

In the case of precast and tilt-upconstruction, cranes often operate in closeproximity to overhead power lines and therisk of injury can be very high.

Builders should plan ahead as far aspossible to maximise safety. Electricitydistribution authorities can isolate mostoverhead power lines when sufficient noticeis given and every attempt should be madeto achieve isolation.

Where overhead power lines are isolated,the electricity distribution authority’s accesspermit should be kept in the craneoperator's possession during operations.

Where there is no access permit, all powerlines must be treated as being live andwithout written confirmation of the linevoltage from the supply authority, thehighest line voltage must be assumed anda 6 metre “danger zone” used.

Regulation 3.64 of the Occupational Safetyand Health Regulations specifies a “dangerzone” around overhead power lines ofdifferent voltages, which must not beentered by employees, plant or material.

This “danger zone” is within:

(a) 0.5 metres for insulated overhead lineor aerial bundled conductor line notmore than 1000 volts;

(b) 1.0 metre for uninsulated overhead linenot more than 1000 volts;

Regulation 3.64

Figure 88.1: CClearance ffor ccranes ffrom ooverhead ppower llines

This illustrationhas beenreproduced withpermission fromSAI Global

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(c) 3.0 metres for overhead line exceeding1000 volts but not more than 33000volts; and

(d) 6.0 metres for overhead line exceeding33000 volts.

WorkSafe Western Australia’s Guidelines forWork in the Vicinity of Overhead PowerLines provides guidance on the operation ofcranes and the use of other plant andequipment in the vicinity of overhead powerlines. The Guidelines promote a “no go”distance beyond the “danger zone” whichshould not be entered by the crane liftinghook. This “no go” distance is thehorizontal distance from the centreline ofthe crane hook to the perimeter of the loadwhich for concrete panels is half the lengthof the lifted edge.

The “no go” distance may need to beincreased if panels are laid down away fromthe crane, particularly for high panels wherethe risk of making contact with overheadpower lines is increased.

Figure 8.1 shows required clearances forcranes from overhead power lines inaccordance with WorkSafe WesternAustralia’s Guidelines.

If, for any reason, it is necessary for aperson or any plant, material or equipmentto enter the “danger zone”, the priorauthorisation of the supply authority mustbe obtained before entry is made.

In instances where it is necessary to operatethe crane within the “no go” zone (but stilloutside the “danger zone”), a dedicatedspotter should be used throughout thesephases of the erection sequence. In thesecircumstances, the erector should alsoimplement the following measures:

• increase the visibility of the power linesby arranging with the supply authoritythe installation of “tiger tail” wrappingaround the lines;

• slow down the normal operating cycle ofthe crane to increase the availablereaction time for assessing distances;

• keep persons not authorised by theerector away from the area;

• clearly instruct all personnel to standclear of the crane and load at all times;

• install warning notices in a prominentposition in the crane cabin to alertoperators to check for the presence ofpower lines;

• dry taglines (tail ropes) made of non-conductive material such as natural fibre,hemp or sisal should be used to controlthe load. Due to their conductiveproperties, synthetic ropes should not beused. The tagline should be preventedfrom approaching or being blown intocontact with any power line; and

• mobile cranes should be provided with asteel earthing chain. The chain shouldbe bolted or welded to the carrierchassis and be of sufficient length toallow at least one metre of chain to bein contact with the ground when thecrane is set up on outriggers. Earthingchain should not be used when thecrane is operating near the rails of anelectric train system.

When operating or travelling in anunfamiliar area, the crane operator shouldalways check for the presence of overheadpower lines.

In the event that the crane does contactlive power lines, or arcing occurs, the craneoperator should observe the followingprecautions:

• remain inside the cabin;

• warn all other personnel to keep awayfrom the crane and not to touch anypart of the crane, rigging, tail ropes orload;

• try, unaided, and without anyoneapproaching the machine, to move thecrane until clear of the power line;

• if the machine cannot be moved away,remain inside the cab. If possible, byusing a safe means of communication,get someone to inform the electricitydistribution authority at once. Take noaction until the distribution authorityconfirms that the conditions are safe;

• if it is essential to leave the cabinbecause electrical contact or arcing hascaused a fire or other life-threateningemergency, jump clear as far away fromthe crane as possible. Do not touch thecrane and the ground at the same time;

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• when moving away from the crane,shuffle or hop slowly across the affectedarea. Large steps should be avoided asone foot could be in a higher voltagearea and the other in a lower voltagearea. Under some circumstances, thevoltage difference between the twoareas could kill (see Figure 8.2); and

• ensure someone remains near the crane,at a safe distance, to warn others of thedanger of approaching.

Following any contact with live power linesor arcing, a competent person shouldinspect the crane for possible damagecaused by the contact before further use.Wire rope should be replaced if it touchesthe power line as the arc will usually weld,melt or badly pit the rope.

In the case of wheeled machinery it isimportant that this inspection consider the

possible degradation of rubber tyres causedby high temperatures.

All tyres suspected of being subjected toheat from any source should be replaced.

Proximity warning devices, insulating boomguards and similar devices all havelimitations and should not be relied uponto give protection against electric shock.

8.8 Operating near bracesand panels The use of mobile plant such as cranes,backhoes, excavators and EWPs, close toconcrete panel braces can be extremelyhazardous due to the risk of panels andbraces being struck and panels collapsing.Braces are designed to resist wind loadsapplied to panels and not to resist impactloadings with moving plant.

Figure 88.2: HHigh vvoltage ccontact

High voltage contactwill result in electricalcurrent flowing down the boomand through the crane to the ground.The ground will then be energized with a highvoltage near the crane and lower voltage further away.

This illustrationhas beenreproduced withpermission fromSAI Global

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Braces that are struck by mobile plant maycollapse in a very rapid and uncontrolledfashion causing panels to fall. A fallingpanel is likely to strike other panels andprogressive collapse of other panels canoccur.

The hazard can be minimised by givingcareful consideration to siting of the craneand the erection sequence as discussed atsection 8.2 of this code.

The builder should be notified of anyinstance where braces are struck by plant.

Particular ccare nneeds tto bbe ttaken wwhen aacrane iis bbeing uused tto eerect sstructuralsteelwork tto pprevent pparts oof tthe ccrane aandthe ssuspended lload ffrom hhitting bbraces aandpanels. EErection oof ssteelwork iin aaccordancewith tthe rrequirements oof AAS 33828 wwillminimise tthe rrisk oof ccontact ooccurring.

Mobile plant should not be operated, ortravel close to, erected concrete panels andbraces unless there is sound reason, eg theuse of an EWP to assist in the installationor removal of braces.

Where it is necessary to operate plant inclose proximity to braces and panels,control measures should be implemented.Control measures include the following:

• use of a spotter to signal the plantoperator to stop the plant in the eventof any part of the plant approaching abrace or panel. Such a system wouldneed to ensure the communicationmethod between the spotter andoperator was effective and take intoaccount factors such as noise on siteand the spotter possibly being out ofview of the operator;

• use of barricading to ensure separationof plant and braces; and

• use of hazard tape, ‘para-webbing’and/or signage to make the braceposition obvious, particularly wherebraces are close to access areas.

Any excavation work carried out in thevicinity of brace footings should beapproved by an engineer to ensure footingsare not undermined.

8.9 Working at height All work at height should be carried out inaccordance with regulations 3.48 to 3.57and the Commission for Occupational Safetyand Health Code of Practice Prevention ofFalls at Workplaces.

The above regulations and code of practicecontain requirements and advice on edgeprotection, fall prevention systems,scaffolding and ladders for safe working atheights.

Useful information may also be found in AS 3828.

Regulation 3.55 specifies that where thereis a risk that persons could fall 2 metres ormore from the edge of a scaffold, fixedstair, landing, suspended slab, formwork orfalsework, guard railing comprising a toprail, mid rail and toeboard, or top rail,toeboard and meshing must be provided.

Regulation 3.55 also requires that wherethere is a risk that persons could fall 3metres or more from any other edge, edgeprotection in the form of guard railingmentioned above, or alternatively a fallinjury prevention system, must be provided.

To reduce the need for working at height, asmany sections of the structure as possibleshould be assembled on the ground beforebeing lifted into their final position. However,personnel are generally required to work atheight to perform the following activities:

• removal of braces from concrete panels;

• attaching the panels to one another orto structural steelwork prior to removalof the braces; and

• application of caulking to vertical jointsbetween panels.

Work at height should either be performedfrom platforms with guardrails, includingEWP, or mobile scaffolding. Portableladders should only be used where othermethods are impracticable. Their use mustcomply with regulation 3.26.

Boom lift type EWP are usually preferableto scissor lifts because they have superiorreach to access more awkward areas anddo not need to be driven next to anerected concrete panel to gain access. Also‘rough terrain’ type boom lifts are moresuitable for poor ground conditions.

Regulations 3.48 to 3.57

Regulation 3.55

Regulation 3.26

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The use of EWP on site must be inaccordance with regulation 4.54. Therequirements for maintenance, inspectionand operation were mentioned in section8.6 of this code.

Before specifying or using an EWP, a checkshould be made as to its suitability for thesite conditions.

8.10 Strongbacks Strongbacks should be located and fixed inaccordance with details shown on the shopdrawings.

Strongbacks should be bolted so they arehard up against the panel, otherwise theymay not adequately prevent damage to thepanel.

8.11 Erection crew The erector should nominate one person inthe erection crew to be directly responsiblefor the direction and coordination of theerection sequence. This person should holda rigging certificate of competency in eitherthe Intermediate Rigging or AdvancedRigging certificate class and haveexperience in erecting concrete panels.

The crane operator must hold a certificateof competency appropriate for the type andcapacity of crane in use.

The size and make-up of the remainder ofthe erection crew is specified in regulation4.54 and is dependent on the maximumrated capacity of the crane used.

All members of the erection crew shouldhave been trained in this code of practice,and at least one of the erection crew oranother person who remains on sitethroughout the erection should hold acurrent first aid qualification.

8.12 Rigging Setting up a rigging system requires carefuland thorough preplanning. The selection ofthe rigging system connecting the concreteelement to the crane should be agreedbetween the erector and the rigger.

The preferred configurations for concretepanel lifting are described in section 4.7.3of this code and shown in Figure 4.3. Referto section 5.2.3 for documentation requiredfor rigging.

The rigging system should distribute equalloads to all lifting points.

Regulation 4.54

Regulation 6.3

Figure 88.3: SSnatch bblock

Regulation 4.54

This illustrationhas beenreproduced withpermission fromSAI Global

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Single, double and four leg slings arecommonly used in the handling of concreteelements. In selecting the sling capacity, theincreased force due to inclination of thesling and the change of direction at reevingpoints should be considered. The includedangle between slings at reeving pointsshould not exceed 120 degrees.

Lifts desirably should be planned so thatrotation of the snatch-block under load isnot required. Where the snatch block isrequired to rotate it needs to have thrustraces or separate swivel bearings asmentioned in section 3.8 of this code.

An inspection and check of the riggingshould be performed prior to lifting by therigger in charge, especially where steel wirerope is being used in the rigging system.This inspection should include a visual checkto ensure the snatch block collar pin is intactand the collar has not become loose.

Where blocks with lockable clamp bolts arenot available, care needs to be taken toensure that the cheek plate clamp bolt isfully tightened and that rubbing andabrasion under load does not occur. SeeFigure 8.3.

The rigging system should be arranged toallow the concrete element to lie in or nearits correct attitude for erection into thestructure.

All components of the rigging system shouldbe checked regularly for damage andexcessive wear, corrosion, etc to ensure theyare appropriate for the loads being lifted.

Lifting clutches should be inspected, priorto each use, for wear and deformation. Ifany deterioration is seen or safety concernsidentified, a proof test should be conductedas mentioned in section 3.5.2 of this code.

8.13 Erection of concretepanels Concrete panels should be erected inaccordance with AS 3850 and the workmethod statement referred to in section 8.3of this code. Before erection commencesthe checklist at section 8.2 should becarried out.

Concrete panels should not be lifted orerected before attaining the minimumconcrete strength on the shop drawings forlifting or erection.

If incorrectly located, faulty or missinglifting inserts are identified, or if concrete ispoorly compacted or cracked close to liftinginserts, immediate contact should be madewith the erection design engineer toestablish an appropriate solution.

It is essential that the order in which thevarious components and members of thestructure are assembled will maintainstability at all stages, allowing for theeffects of high winds on partially completedstructures. Overnight it may be necessary tostabilise incomplete structures usingmeasures considered as part of the initialdesign and forming part of the designederection sequence. They should not be anad hoc means of stabilisation.

The builder should provide the erector withverification that the concrete in bracefootings has attained its required strengthbefore concrete panels are erected.

For site-cast panels, the adhesion of thepanel to the casting bed has to be broken.At all times panels should be liftedsmoothly to avoid shock loading which caninduce cracking in the panel.

For face-lifted panels, load on the craneshould not be increased if the panel doesnot come free when the crane's loadindicator registers the combined weight ofthe panel, rigging and any attachmentssuch as strongbacks.

For edge-lifted panels, load on the craneshould not be increased if the panel doesnot come free when the crane's loadindicator registers 65% of the weight of thepanel plus 100% of the weight of the riggingand any attachments such as strongbacks.

In all circumstances where a lift has beenstopped, procedures such as wedging orjacking should be as determined by thebuilder. Such procedures need to beundertaken or directly supervised by therigger in charge of the erection. Whereused, wedges should be aligned with theline of lifting inserts unless writteninstructions state otherwise.

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Each concrete panel should be lifted so that,while suspended, it leans away from thecrane. The situation when the panel tiltstowards the crane is extremely dangerous. Ifpart of the lifting system fails, in thissituation, the panel will fall against thecrane and may cause the crane to overturn.The requirement to lift panels in this mannercan exist when panels are cast on theoutside of the building to be constructed.

Bracing inserts are usually located on thesame face of the panel as the lifting inserts.

Good practice dictates that wheneverpossible, the braces should be fixed to theconcrete panel before lifting.

During the lifting process, the braces shouldnot hang below the level of the base of thepanel. This may be achieved by the use ofadjustable length braces or by the use oftaglines.

Where, under unusual circumstances, it isnecessary to attach braces to the panelafter it has been positioned, the panelshould be held firmly, just past vertical bythe crane while the braces are attached.Where bracing inserts are located on theopposite side of the panel to the liftinginserts, the panel should be tilted slightlyback on to the rigging and the bracesattached.

No pperson sshould eever wwork oon aa cconcretepanel tthat iis lleaning ttowards tthem oor bbeplaced bbetween aa ppanel bbeing llifted aandanother ppanel, wwall oor oobject, wwheremovement oof tthe ppanel ccould ccausecrushing. TThis aapplies uuntil tthe rrelease oofthe ccrane ffrom tthe ppanel.

The following practices should be followedduring the lifting and placing of concretepanels:

• lifting gear and sheaves to be in goodcondition and lifting clutches fullyengaged prior to lift occurring;

• lifting clutch release lines are fitted toenable clutches to be disengagedwithout the need for workers to climbon top of the panel;

• whenever possible, panels should belifted with the rigging equipment in viewof the crane operator as the crane hookis hoisted;

• all personnel should be clear of the areawhere the panel may fall when lifting,tilting or rotating the panel fromhorizontal to vertical;

• when taglines are used to control theswing of the panel, personnel shouldposition themselves clear of the paneledges as the panel may slew sideways.Clutch release ropes should never beused as taglines;

• no attempt should be made to lift anderect panels in strong winds where windspeeds exceed those specified by thecrane manufacturer;

• crane support should be maintaineduntil all braces have been installed andsecured to the panel and footings;

• the crane operator should never leave thecrane while the panel is connected; and

• no brace should be connected toanother panel for support unless clearlyspecified on the shop drawings.

After erection of a panel it is the builder’sresponsibility to check braces, brace boltsand pins at regular intervals to ensure theymaintain the required capacity. Theseintervals should be determined by thebuilder and erector at the preplanning stage(see section 8.2 of this code). See alsosection 9.1, Installation and inspection oftemporary bracing.

8.14 Modifications Modifications to concrete panels and otherprecast concrete elements and theirassociated supporting components andconnections, may only be carried out withthe approval of the project design engineer.The need for modification may be due torelocation or changes to sizes of windowsand doorways.

It is a requirement of the BuildingRegulations 1989 that the relevant localgovernment authority be notified to obtainthe consent of the building surveyor priorto proceeding with any variation from, oralteration of, approved plans, drawings andspecifications. This requirement, of course,applies throughout the life of the building.

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C O N T E N T S

PAGE

9.1 Installation and inspection of temporary bracing................................................... 61

9.2 Superimposed loads............................................... 62

9.3 Levelling pads and shims ...................................... 63

9.4 Grouting of the base .............................................. 63

9PartTemporary bracedcondition

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9.1 Installation andinspection of temporarybracingBracing should be installed in accordancewith AS 3850 and the approved shopdrawings unless prior written approval isobtained from the erection design engineer.The capacity of a brace varies with theinstallation angle of the brace.

Where a single brace is used eg on narrowpanels, to brace a panel, particular care isrequired on site to prevent impact ordamage to the brace. Panels supported bya single brace only are very susceptible tofailure by panel rotation about the brace.

Where single braces are used, they shouldhave a minimum of two fixings at each end.Care needs to be taken in the installationof these two fixings as their closeness mayreduce the effective anchorage of each.

Usually two braces are used to supporteach panel. Three braces may be necessaryon large panels and in situations whereload controlled expansion anchors are usedin brace footings since the capacity of theseanchors may be less than the capacity ofthe brace itself.

However, where more than two braces areused there is difficulty in ensuring an evenload distribution. Allowance should bemade in the design for the potentiallyuneven loading where more than twobraces are used on a panel.

Two braces may not be necessary whereconcrete panels are provided with erectionbrackets or permanent connections to otherrestrained elements such as steel portalcolumns or walls forming a stable “box”structure.

A brace connected to one concrete panelshould not be connected to another bracedpanel for support unless this is clearlyspecified on the shop drawings.

The angle of installation of braces shouldbe shown on the shop drawings. Braces areusually installed at an angle of 450 to 60o

and square to the line of the panel (seeFigure 9.1) unless the erection designengineer has considered anotherarrangement and it is shown on the shopdrawings. If site conditions prevent thebraces from being installed in the positionsshown on the shop drawings, the erectiondesign engineer should be consulted andapprove an alternate location and anyassociated changes necessary such as largerbraces and higher capacity base fixing.

Temporary bracedcondition

Figure 99.1: CConcrete ppanel bbracing, ppreferred aarrangement

Minimum 20mmdiameter threadedcast-in insert

Pan

el h

eigh

t

Typi

cally

2/3

pane

l he

ight

Required capacity ofbrace and installationangle to be nominatedon shop drawings

Type of fixing to benominated on shopdrawings

Floor slab45-60˚

90˚ 90˚

Brace Brace

Panel

Plan View

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Figure 9.2 shows the proper method ofbracing corner panels without having toskew the braces for attachment to the floorslab. Attachment of braces to concreteblocks (deadman) in the “leave-out area”between the floor slab and the panelsallows the braces to be properly locatedwithout skew. Panel stability is reducedwhen braces are skewed.

Bracing feet (or shoes) need to be designedto prevent lateral displacement of the shoefrom the fixing insert after installation.

The preferred location of bracing points in aconcrete panel is at two-thirds of theheight, measured from the base of thepanel and at least 600mm above the centreof gravity. Where it is necessary to locatebracing points below the panel’s centre ofgravity, this needs to be specificallydesigned and detailed on the shopdrawings. Special provisions should bemade to prevent "kick-out" of the base ofthe panel in these situations.

Regular visual inspection of panels in thebraced condition needs to be carried out tocheck that the braces and bracing insertconnections have not been loosened bywind action.

A check of the torque of the bolts shouldbe carried out 24 hours after erection andat appropriate intervals after installationdetermined in the erection planning stage(see section 8.2 of this code), particularlyafter high winds, to ensure the bolts arecorrectly torqued and the braces have notmoved.

9.2 Superimposed loadsSuperimposed loads should not be appliedto concrete panels in the temporary bracedcondition unless clearance is obtained froman engineer. Such loads should have beenspecifically allowed for in the design. Theseinclude loads from erection of steelworkand other attachments.

The erection of roof steelwork can exertsignificant outward loads onto bracedpanels. In some cases these forces may besufficient to overload the temporary bracingand cause failure of the bracinginserts/bolts.

During release of a rafter’s weight from thecrane, the braces adjacent to the rafterbeing erected should be monitored andadjusted accordingly.

As well, substantial inward forces may beimposed on braced panels and fixings tosteelwork as a result of temporarilyunrestrained steel rafters rotating andmoving sideways under self-weight anderection loads. The resulting forces mayoverload bracing and fixing inserts.

To ensure safe work methods during theerection of steelwork, the project designengineer should consider the effect of theerection sequence on stability in accordancewith AS 3828. Clear instructions should beprovided to the steel erector for therequirement of any temporary bracing forsteelwork. Where such bracing is required itshould be detailed on the shop drawings sothe steel erector can make provision forsuch bracing and riggers do not have toaccess an unstable structure.

Figure 99.2: CCorner bbracing

Right Wrong

Floor slabWall panel

Typically 900 to 1500 mm Brace Skewed Braces

Deadman

Deadman

Floor slab

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9.3 Levelling pads and shimsShims carry the load of the concreteelement which needs to be adequatelysupported to prevent movement until theelement is incorporated in the mainstructure. A levelling pad (mortar bed) or alevel bearing area is used to provide a levelseating for the shims.

See section 4.14.3 regarding horizontalrestraints of concrete panels.

Concrete elements should be designed tosit on only two localised shimming pointswhen initially erected. Use of multipleshimming points cannot ensure uniformdistribution of load due to difficulties withconstruction tolerances.

Shims should be used on solid foundationsthat are designed to carry the imposedloads.

Shims should be located at least 300 mmin from the ends of the element andbearing support, unless otherwise specified.This is particularly relevant for thin concretepanels where edge breakout can occur ifshims are placed too close to bottomcorners. See Figure 9.3.

Direct concrete-to-concrete, or concrete-to-steel bearing should be avoided.

The gap between the bottom of theelement and the footing should ultimatelybe grouted or dry packed, to transfer theload to the footings.

9.4 Grouting of the baseAfter concrete panels have been finallyplumbed, the base of the panel and anygrout pockets need to be fully groutedunless otherwise stated on the drawings.Grouting and appropriate strength gainshould take place before any formwork isremoved from beams or slabs supported bya panel.

The weight of the concrete panel, and anyloads applied to it before grouting, will beapplied to the supporting structure at twodiscreet points where the levelling shimsare located.

Fig 99.3: LLevelling sshims

Concrete panel

150mm MIN

300 mm MIN(Unless otherwise specified)

Shims

Grout between paneland footing

40mm MAX

Footing

This illustrationhas beenreproduced withpermission fromSAI Global

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10.1 Fixing to final structure .......................................... 65

10.2 Inspection prior to and removal of braces............ 65

10PartIncorporation into final structure

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10.1 Fixing to final structureThe fixing of concrete panels should be inaccordance with the structural drawings andthe shop drawings including any changesmade to specifications or instructionsissued by the project design engineer orthe erection design engineer.

All steelwork forming part of the structureshould be erected in accordance with AS3828 which sets out recommended safeworking provisions and practices supportedby training, for those involved in erection ofthe steelwork including associated trades.

The recommendations also relate to otherworkers on the site who may be at riskfrom the erection of the steelwork.

A key requirement of AS 3828 is thepreparation of a work method statement bythe contractor which clearly identifies themethod used to erect the steelwork andhow it will be fitted into the overallworkplan for the project.

10.2 Inspection prior to andremoval of bracesPanel braces should not be removed untilthe concrete panel is incorporated into thestructure and the structure is capable ofsupporting the panel for the applied loads.

Prior to the removal of braces, the structureshould be inspected to ensure that allstructural elements affecting stability aresecurely fixed to the panels. This inspectionshould be carried out by the project designengineer and written approval to removethe braces given to the builder.

The removal of braces from a panel shouldbe planned and carried out in a controlledmanner to prevent risk of injury anddamage to equipment.

Braces to be removed from site should beloaded onto transport in such a manner asto allow safe transport and avoid damageto them.

Braces should be maintained and inspectedbetween each use to ensure all componentsare correct and in good working order.

Incorporation into final structure

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A1: Generaldefinitions

BUILDER

The company or personresponsible for theconstruction of the completedbuilding and who has controlof the building site.

BUILDING DESIGNER

The person responsible forthe overall design of thebuilding. The buildingdesigner will usually beresponsible to the client.

CLIENT

The owner of the building or the company or personresponsible for developingthe building.

CONCRETE ELEMENT

Either a concrete panel or other precast concreteelement.

CONCRETE PANEL

A concrete panel that ismanufactured as a separateand movable panel for thepurpose of being incorporatedas a wall (including aretaining wall) once theprocess by which the panel ismanufactured is complete, butdoes not include a column,beam or paving slab or apanel that is for decorativepurposes only.

The panel may be precaston-site, or off-site in afactory or casting yard.

ENGINEER

Means a qualified practisingengineer. A qualifiedpractising engineer shouldpossess an undergraduatequalification in engineeringand have at least threeyears work experience in an engineering field.

ERECTOR

The company or personresponsible for erecting theconcrete elements.

ERECTION DESIGN ENGINEER

The engineer responsible forthe design for the erection ofthe concrete elements of thebuilding and the stability ofthe concrete elements duringconstruction. The erectiondesign engineer should be aqualified practising engineerand be competent to practicein the structural engineeringfield. The erection designengineer may also be theproject design engineer.

EXCLUSION ZONE

An area over which concreteelements or other items,while being lifted, aresuspended or pass over ormay fall or drop into.Workers and members of thepublic should, as far aspracticable, be preventedfrom accessing this areawhile lifting is taking place.

PRECASTER

The company or personresponsible for manufacturingthe concrete elements.

PRECAST CONCRETEELEMENT

A concrete element usually,but not necessarily,manufactured under controlledconditions in a factory orcasting yard and subsequentlytransported to and erected ona building site.

PROJECT DESIGN ENGINEER

The engineer responsible forthe engineering design of thebuilding. The project designengineer should be aqualified practising engineerand be competent to practicein the structural engineeringfield. The project designengineer may also be theerection design engineer.

SHOP DETAILER

The person responsible forpreparing the shop drawingsof the concrete elements.The shop detailer should bea person who, throughtraining or experience, isable to undertake the workas described in thisdocument.

TILT-UP CONCRETE PANEL

An essentially flat concretepanel designed in accordancewith AS 3850 and AS 3600;cast in a horizontal position,usually on-site; initially liftedby rotation about one edgeuntil in a vertical or near-vertical position; transportedand lifted into position ifnecessary; and then stablizedby bracing members untilincorporated into the finalstructure.

Appendix ADefinitions of terms used in this code

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TILT-UP WORK

Means any of the following:

(a) the manufacture,transport, cranage,temporary storage,erection or temporarybracing of a concretepanel;

(b) the fixing of a concretepanel for theincorporation of thepanel as a wall (includinga retaining wall);

(c) the removal of temporarybracing of a concretepanel.

TRANSPORTER

The company or personresponsible for transportingthe concrete element.

A2: Technicaldefinitions

BRACES

Certified temporarycomponents providingstability in preventing a tilt-up concrete paneloverturning. Both ends arefitted with a pinned foot,allowing a degree of freedomfor variable fixing angles.They are intended to resisthorizontal construction andwind loads. Braces shouldnot be used as props.

BRACING FEET OR SHOES

The components thatconnect braces onto a panelor onto the bracing supportor footing via pinnedconnections and inserts.

BRACING INSERT

A component cast into aconcrete panel or cast intoor fixed to a brace footing,for later attachment of abrace.

CONNECTIONS

A method by which one ormore concrete or steelelements are joined together.The purpose of connectionsis to transfer load and/orprovide stability.

CRANE RATED CAPACITY

The maximum load whichmay be applied to the cranewhile in a particular workingconfiguration and under aparticular condition of use.

CRANE STANDING AREA

The base on which the craneis supported during erectionof the concrete elements.Referred to as the erectionplatform in AS 3850.

EDGE LIFTING

A method of lifting wherebylifting inserts are cast withinthe concrete element edgeso that the element is liftedand hangs vertically fromthat edge.

EXPANSION ANCHORS

Anchors placed in holesdrilled in hardened concretewhich rely on expansiondevices within the hole toprevent pullout under load.The two types of expansionanchors are:

Load ccontrolled

Anchors that have a wedgeand expansion-shield systemwhere the wedge is directlyconnected to the appliedload. Increases in loadabove the retained preloadfrom the initial torque willincrease the expansion force.

This type of expansionanchor is the only typepermitted in tilt-up andprecast construction.

Deformation ccontrolled

Anchors that are expandedonly during installation.Application of further load tothe anchor does not increasethe expansion force.

This type of anchor is notpermitted in tilt-up andprecast construction.

FACE LIFTING

A method of lifting wherebylifting inserts are cast withinthe face of a concreteelement so that when it islifted it hangs at an angle tothe vertical.

FIXING INSERT

A component cast into orfixed to the concreteelement and used to tie itinto the structure.

FIXINGS

The hardware components ofall connections includingbolts, washers, weld plates,anchors etc.

JOINTS

The gap between adjoiningconcrete elements orbetween a concrete elementand some other portion ofthe structure.

LEVELLING SHIMS

Proprietary material usedunder concrete elements tosupport them in their correctposition until the finalconnection is made.

LIFTING BEAM

A certified component of therigging system that transfersthe load from the concreteelement to the crane.

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LIFTING CLUTCH

A certified proprietary quick-release device used toconnect the crane rigging tothe lifting insert.

LIFTING INSERT

A component cast into theconcrete element for lifting it during erection.

LIFTING SPREADER

A certified device thatspreads the lifting ropes anddistributes the lifting load.

LIMIT STATE FACTOR (LSF)

The number by which thefailure load is divided togive the working load limit(WLL) as referenced in AS3850.

PROPRIETARY COMPONENTS

Components manufactured ina factory environment andcarrying a trademark orregistered name.

PROGRESSIVE COLLAPSE

A continuous sequence offailures initiated by the localfailure of one part of thestructure.

PROPS

Certified temporarycomponents supportingloads. Both ends of the propare fitted with rigid footplates that provide supportbetween two parallelsurfaces. Props should notbe used as braces.

REINFORCEMENT

Structural rreinforcement

Reinforcement, includingreinforcing steel andprestressing tendons,provided for the integrity ofthe completed structure.

Additional rreinforcement

Reinforcement additional tothe structural reinforcement,provided to resist forcescaused by transport orerection loads.

Component rreinforcement

Reinforcement placed inconjunction with lifting,bracing and fixing inserts sothat they can attain theirdesign capacities.

RIGGING SYSTEM

A system of certified re-useable lifting equipment thatmay include lifting clutches,slings, sheaves, lifting orspreader beams or othermechanical devices toconnect the crane to theconcrete element being lifted.

SHEAR CONE FAILURE

The type of failure reachedwhen tension is applied toan insert embedded inconcrete. When failureoccurs a cone of concrete aswell as the insert is pulledfrom the main body of theconcrete element.

SHOP DRAWING

A detailed drawing of aconcrete element used in themanufacturing and erectionprocesses.

STRONGBACK

A specified temporary steelmember fixed to a concreteelement to provide localisedstrengthening during lifting,transport or erection.

TAGLINE OR TAIL ROPE

A non-conductive line (egfibre rope) attached to theelement being erected tohelp control the elementduring lifting and placement.

WLL (WORKING LOAD LIMIT)

The maximum load that maybe applied to an item,component or system.Formerly referred to as thesafe working load (SWL).

WORK METHOD STATEMENT

A document setting out safeworking procedures.

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Appendix BSample documents, schedules andshop drawing

PROJECT

SITE ADDRESS

CONCRETE PANEL SCHEDULE: PLANNING

Planning Task Action Name Initiation Date Receipt Date

Notification to WorkSafe Western Australia BuilderCommissioner of intention to cast concrete panels in accordance with AS 3850

Construction programme prepared Builder

Shop drawings prepared Shop Detailer

C.P.S. PROPERTIES completed Builder

Concrete element layout plan showing Builder/site constraints, stacking sequence, Site Manager/crane position/s, erection sequence and Erectortemporary brace position

Shop drawings and layout plan marked Erection Designup and signed by engineer Engineer

Approved shop drawings checked for Project Designstructural intent by engineer Engineer

Work Method Statement: Site ManagerSITE ESTABLISHMENT/SERVICES

Work Method Statement: Site ManagerCONCRETE ELEMENT PRODUCTION

Work Method Statement: ErectorCONCRETE ELEMENT ERECTION

Work Method Statement: ErectorSTEEL INCORPORATION INTO FINAL STRUCTURE

Local Government Authority Building Licence Builder

Reinforcement scheduled from approved Buildershop drawings

C.P.S. HARDWARE completed Builder

Panel casting sequence programmed from Site Managerconstruction programme and layout plan

Workplan Master File: BuilderPLANNING/PRODUCTION/ERECTION

HOLD POINTConcrete element production must not commence until all planning requirements are satisfied

Sheet 1

70

page

This illustration hasbeen reproduced fromthe Concrete PanelBuildings Briefing 08 January 2003 withpermission of CementConcrete & AggregatesAustralia

Sheet 2

71

page

PROJECT

SITE ADDRESS

CONCRETE PANEL SCHEDULE: PROPERTIES

DESIGN ENGINEER

REVISION DATE

Panel Length Height Thickness Gross Openings Nett Perimeter Volume Tonnes# (mm) (mm) (mm) (m2) (m2) (m2) (mm) (m3)

TOTALS:

Sheet 3

72

page

PROJECT

SITE ADDRESS

CONCRETE PANEL SCHEDULE: PROPERTIES

HOLD POINTConcrete element production must not commence until all the planning requirements are satisfied

Production Task Action Name Completion Date

Audit all panel components against Site ManagerC.P.S. HARDWARE are on site

Audit scheduled reinforcement and “shake out” Site Managerinto individual panels

Set out casting beds in accordance with Site Managerconcrete element layout plan

Provide compacted limestone (or alternative) Site Manageraccess ramps and slab edge protection for concrete agitator trucks

KEEP ELECTRIC LEADS CLEAR OF ALL VEHICLE ACCESSWAYS

START concrete element production in accordance with panel casting programme and Site ManagerC.P.S. QUALITY CONTROL

Maintain daily concrete delivery and test records for Site ManagerC.P.S. QUALITY CONTROL (test as per AS 1379)

Set out and permanently mark panel positions on footings. Site ManagerVerify dimensions “close-out” with layout plan

Clearly mark panel level pad positions on footings and Site Managerrecord pad thicknesses on concrete element layout plan

MAINTAIN STRICT HOUSEKEEPING AND CLEANLINESS POLICY

C.P.S. QUALITY CONTROL completed, test results Site Managerrecorded and completed

Strip formwork, cleanup, remove from erection area. Site ManagerClearly mark panel number on panel base

Audit temporary strongbacks and falsework delivered in Site Manageraccordance with shop drawings and layout plan

Audit temporary brace insert bolts with 20mm Site Managergalv. structural and spring washer assembly

Audit temporary brace torque controlled floor anchors Site Managerwith 20mm galv. structural washer assembly

HOLD POINT

Concrete element erection must not commence until all the production requirements are satisfied

Sheet 4

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PROJECT

SITE ADDRESS

CONCRETE PANEL SCHEDULE: QUALITY CONTROL**to be completed with signed/certified shop drawing

DESIGN ENGINEER

Panel Revision Bond- Dimen Reinf. Hardw. Services Poured Mpa Test# breaker (mm) Sched Sched Sched

Certified 1st 2nd 3rd 4d./7d.

PANEL QUALITY SUPERVISED BY:

INSPECTED & RECORDED BY:

AUTHORISED TO LIFT BY:

Date:

This is to certify that the above listed concreteelements have been manufactured in accordance with the approved shop drawings.

Name:

Signature:

Date:

Sheet 5

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SITE ADDRESS

DATE

CONCRETE PANEL SCHEDULE: ERECTION

HOLD POINT

Concrete element erection must not commence until all the production requirements are satisfied

Erection Task Action Name Completion Date

Provide compacted limestone (or alternative) access ramps Site Managerand slab edge protection for crane

Identify and clearly mark any U/ground services in Site Manager/“angle of repose” vicinity of crane standing area Erector

Traffic management plan approved with valid permits Site Manager/and/or personnel deployed in accordance with ErectorWork Method Statement: CONCRETE ELEMENT ERECTION

Erection and fall zones are warning barricaded from Site Manager/unauthorised entry and from public safety Erector

Crane supplied is of capacity planned in layout plan and Site Manager/in approved service condition Erector

Rigging equipment and hardware of capacity as approved Erectoron shop drawings, layout plan and Work Method Statement

Crane and rigging personnel demonstrate technical Site Manager/competencies and complete site induction Erector

All erection personnel have participated and “signed off” Erector the JOB SAFETY ANALYSIS

Correct diameter drill-bits/adequate sized rotary hammer Erectordrills, at least 3 suitable panel bars, rotary socket wrenches and manual torque socket wrench

KEEP ELECTRIC LEADS CLEAR OF ALL CONCRETE ELEMENTS BEING ERECTED

Temporary bracing anchors to be torque “preloaded” on Erectorinstallation ONLY and recorded on C.P.S. TORQUE REGISTER

All concrete elements to be aligned, base restrained, Erectorin plumb and temporary bracing anchors to be checked for “slip-load” (70%) preload

HOLD POINT

Incorporation of structural steel into final structure must not commence until all the concrete element erection requirements are satisfied

Sheet 6

75

page

PROJECT

SITE ADDRESS

DATE

STRUCTURAL STEEL INCORPORATION INTO FINAL STRUCTURE

HOLD POINT

Incorporation of structural steel into final structure must not commence until all the concrete element erection requirements are satisfied

Structural Steel Erection Task Action Name Completion Date

Provide compacted limestone (or alternative) Site Manageraccess ramps and slab edge protection for crane and EWP

Identify and clearly mark any U/Ground services Site Manager/in “angle of repose” vicinity of crane standing area Erector

Identify and clearly mark any slab penetrations and Site Manager/concrete element temporary bracing obstructions Erectoraffecting EWP and crane mobility

Traffic management plan approved with valid Site Manager/permits and/or personnel deployed in accordance Erectorwith Work Method Statement: STRUCTURAL STEEL INCORPORATION INTO FINAL STRUCTURE

Erection and fall zones are warning barricaded Site Manager/from unauthorised entry and for public safety Erector

Structural steel fabricated and delivered to site Site Manager/is in accordance with shop drawings, structural Erectorsteel layout plan and Work Method Statement

Crane, EWP and rigging personnel demonstrate Site Manager/technical competencies and complete site induction Erector

All erection personnel have participated and Erector “signed off” the JOB SAFETY ANALYSIS

Fall prevention systems are recognised, maintained Erectorand monitored throughout structural steel erection

On completion of erection of structural steel the Project Designentire structure inspected for structural compliance Engineer

HOLD POINT

Concrete element temporary bracing removal and loading of roofing material and/or plant onto structural steel must not commence until structure is inspected and written approval

of compliance by project design engineer.

Record concrete element temporary bracing Site Managerremoval on C.P.S.TORQUE REGISTER

Sheet 7

76

page

PROJECT

SITE ADDRESS

CONCRETE PANEL SCHEDULE: TEMPORARY BRACE LENGTH/TORQUE REGISTER

ERECTION DESIGN ENGINEER

PROJECT DESIGN ENGINEER

RIGGING CONTRACTOR

Panel Brace Preload Slipload Remark Brace Preload Slipload Remark Insp/ Release# ‘A’ ‘B’ Cert

TORQUE PRELOAD ONCE ONLY

STRUCTURAL INTEGRITY INSPECTED/APPROVED BY:

Sheet 8

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page

Legislation referenced • Occupational Safety and Health Act 1984

• Occupational Safety and Health Regulations 1996

• Building Regulations 1989

Publications referencedCommission for Occupational Safety and Health

• Guidance Note: General Duty of Care in Western Australian Workplaces

• Codes of Practice: First Aid Facilities and Services, Workplace Amenities and Facilities,Personal Protective Clothing and Equipment

• Code of Practice: Prevention of Falls at Workplaces

WorkSafe

• Guidelines for Work in the Vicinity of Overhead Power Lines

Australian SStandards

• AS 1012 Methods of testing concrete

• AS/NZS 1170.0 Structural design actions – General principles

• AS/NZS 1170.1 Structural design actions – Permanent, imposed and other actions

• AS/NZS 1170.2 Structural design actions – Wind actions

• AS/NZS 1170.4 Minimum design loads on structures – Earthquake loads

• AS 1379 Specification and supply of concrete

• AS 1418 Cranes (including hoists and winches)

• AS 2550 Cranes- Safe use

• AS 3600 Concrete structures

• AS 3610 Formwork for concrete

• AS 3799 Liquid membrane-forming curing compounds for concrete

• AS 3828 Guidelines for the erection of building steelwork

• AS 3850 Tilt-up concrete construction

• AS 4100 Steel structures

Appendix CReferenced documents and further reading

78

page

Other documents referenced• Building Code of Australia, published by

the Australian Building Codes Board.

The Building Code of Australia 96 (BCA96)is a uniform set of technical provisions forthe design and construction of buildingsand other structures throughout Australia.It allows for variations in climate andgeological or geographic conditions. TheBCA is produced and maintained by theAustralian Building Codes Board (ABCB) onbehalf of the Commonwealth Governmentand each State and Territory Government.The BCA96 is available as a stand-aloneproduct or with value-added productsincluded. The stand-alone versions areavailable from the ABCB’s PrincipalPublishers, Standards and CanPrint, inelectronic and hard copy formats.

• Z48: Precast Concrete Handbook,produced by the National PrecastConcrete Association of Australia andpublished by the Concrete Institute ofAustralia.

• Z10: Recommended Practice, Design ofTilt-up Concrete Wall Panels, publishedby the Concrete Institute of Australia.

Further reading, advice andinformationAdditional and more detailed information canbe obtained from the above organisationsand their websites and some of thesedocuments are listed below.

Cement & Concrete Association of Australia

• Tilt-up Construction Notes

• Briefing Notes (monthly publication)

National Precast Concrete Association of Australia

• National Precaster (Newsletter)

In addition to the above organisations andpublications, manufacturers of hardware,including drilled-in inserts, associated withthe precast and tilt-up concrete industriesall publish design and technical informationon their products. Reference should bemade by designers and users to theparticular supplier's technical informationfor advice before specifying or using any oftheir products.