INDUSTRY GUIDE FOR FORMWORKCONSTRUCTION INDUSTRY SOUTh AUSTRAlIA

JUNE 2012

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INDUSTRY GUIDE FOR FORMWORK

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Acknowledgments

This guidance material has been developed by a tri-partite industry working party and has involved extensive consultation with industry and other special interest groups. The contribution of the following organisations is acknowledged:

• BuiltEnvironsPtyLtd• Construction,Forestry,MiningandEnergyUnion• HansenYunckenPtyLtd• HindmarshAustralia• MitconFormworkPtyLtd• NewgenFormworkers• SystemFormworkPtyLtd• SafeWorkSA

Diagrams courtesy of:

• BovisLendLease• WorkplaceHealthandSafetyQueensland• SafeWorkSA Photographs courtesy of:

• Construction,Forestry,MiningandEnergyUnion• MitconFormworkPtyLtd• SystemFormworkPtyLtd• HindmarshAustralia

Disclaimer

Information provided in this publication has been prepared by industry

representatives and is designed to prevent injury to anyone engaged in

erecting and dismantling formwork and associated equipment.

This publication is correct at the time of printing and is provided as general

information only. In utilising general information about workplace health

andsafety,thespecificissuesrelevanttoyourworkplaceshouldalwaysbe

considered.

Theremaybeadditionalrisksataworkplacethathavenotbeenspecifically

addressedinthisguidance.UndertheSouthAustralianoccupational

healthandsafetylaws,suchrisksmustbeidentifiedandcontrolmeasures

implemented and reviewed to eliminate or minimise exposure to these risks.

Usersofthisguidancematerialshouldbeawarethatitisbasedoncurrent

knowledge and construction methods within the industry and is not intended

to exclude other methods or processes that can also meet the required

safetystandards.Thisindustryguide,onanyparticularaspectoflegislation,

is not to be taken as a statement of law. To ensure compliance with your

legalobligationsyoumustrefertotherelevantActs,Regulationsand

ApprovedCodesofPractice.Thispublicationmayrefertolegislationthathas

beenamendedorrepealed.Whenreadingthispublicationyoushouldalways

refer to the latest laws.

PrefAceThisIndustryGuideforFormworkisbasedontheSouthAustralianOccupational Health, Safety and Welfare Regulations 2010.GiventhatSouthAustraliaislikelytoadopttheharmonisedlegislation,itisrecommendedthat readers of this document also become familiar with therequirementsoftheWorkHealthandSafety(WHS)legislation once it comes into effect.

SafeWorkSA,incollaborationwithmembersoftheConstructionIndustry,hasproducedthisguidancetoprovideemployers,self-employed,andemployeeswithpractical advice on preventing injury to anyone engaged in erecting and dismantling formwork and associated equipment.

AspartoftheSAConstructionIndustryOHSCommittee’sstrategytoaddressareasofhighrisk,itwasagreedthat the creation of appropriate industry guidelines for erecting and dismantling formwork and associated equipment was a priority.

It was further agreed that the codes of practice and guidelines,existinginotherstates(Queensland,NewSouthWalesandVictoria)andoperatingeffectively,couldbe utilised in the development of a similar resource for SouthAustralia.

The objectives of this industry guide are to:

• givepracticaladviceaboutwaysto manage exposure to risks associated with work involving the assembly, erection, alteration and dismantling of formwork

• contributetothedevelopmentof consistent high standards for safe work in the construction industry that are conducive to best practice at the workplace.

It is not intended that this guide be applied to single-storey housing.

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conTenTs1. Introduction 4 1.1 Fallsfromheight–limitationsofharness 4 systems for formwork activity

2. Design 5 2.1 Safedesignofbuildingsinrelationtoformwork 5 2.1.1 ‘Buildability’ 5 2.1.2 Materials 5 2.2 Formworksystems 6 2.2.1 Safeformworkdesignandverification 6 2.2.2 Formworkdesigncertificationrequirements 6 2.2.3 Documentation 7 2.2.4 Designvariations 8 2.2.5 On-sitecoordinationandverification 8

3. coordination and administration 9 3.1 Workprogram 9 3.2 Housekeeping–accessandstorage 9 3.2.1 Accessandegress 9 3.2.2 Materialstorage 9 3.2.3 Rubbishstorageandremoval 9 3.2.4 Storagetominimisemanualtaskrisks 9 3.3 Training 10

4. Work systems 10 4.1 Formworkerection–traditionalsystems 10 4.1.1 Foundations 11 4.1.2 Falsedeck 11 4.1.3 Erectingframes 11 4.1.4 Installingbearers 12 4.1.5 Installingjoists 12 4.1.6 Fallprotectionfromtheformworkdeck 12 4.1.7 Edgeprotectionontheformworkdeck 13 4.1.7.1 Formworkconstructionzonephysicalbarriers 13 4.1.7.2 Edgeprotectiononcompleteddecks 13 4.1.8 Layingaformworkdeck 13 4.1.8.1 Gettingstarted–safeaccess 13 4.1.8.2 Typicalworksystemforaleadingedge 15 4.1.8.3 Layingaformplydeck 15 4.1.8.4 Layingametaldeck 16 4.1.9 Cantileverrequirements 16 4.1.10 Penetrations 16 4.1.11 Workingzonesforformworkersandothers 17 4.1.12 Changingfloorlevels 18 4.2 Formworkerection–modularformworksystems 18 4.2.1 Basicmodularsystems 18 4.2.2 Training 18

4.3 Strippingformwork 18 4.3.1 Generalformworkstripping 18 4.3.2 Safeworkmethodstatements 18 4.3.3 Certificationpriortostripping 19 4.3.4 Exclusionzone 19 4.3.5 Dropstripping 19 4.3.6 Bondreduction 19 4.4 Craneandotherloadhandlingsystems 19 4.4.1 Loadingmaterialsduringformworkconstruction 19 4.4.2 Slingingloads 19 4.4.3 Liftinggear 20 4.4.4 Liftingformworkmaterials 20 4.4.5 Liftinglugs 20 4.5 Useofladders 20

5. special requirements for wall and column forms 21 5.1 Bracingforwindloading 21 5.2 Accessplatforms 21 5.3 Liftingmethods 21

6. special requirements for slip forms and jump forms 22 6.1 Accessandegress 22 6.2 Workplatforms 23 6.3 Trailingscreensandplatforms 23 6.4 Climbingtheform 23 6.5 Training 24 6.6 Healthissuesandamenities 24 6.7 Engineeringissues 24 6.8 Emergencyissues 25

7. falling objects 26 7.1 Hazardcontrols 26 7.2 Preventtheobjectfromfalling 26 7.3 Perimetercontainmentscreens 26 7.3.1 Screenheightatbuildingstep-ins 26 7.3.2 Perimeterscreengaps 27

8. Health concerns 27 8.1 Noise 27 8.2 Dustandatmosphericcontaminants 28 8.3 Manualtasks 28

APPenDIces 29

Appendix1:Definitions 29

Appendix 2: Training 30

Appendix3:Sampleengineer’scertificationletters 31

Appendix 4: construction checklist 33

Appendix5:Samplestructural(pre-pour)certificate 34

Appendix 6: Defects commonly found in 35 formwork systems

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1. Introduction

Formworkisthesurface,supportsandframingusedtodefinetheshapeofconcreteuntiltheconcreteisself-supporting(seeAS 3610-1995 Formwork for Concrete).

Forthepurposesofthisguide,theformworkassemblyincludes:

• theformsonwhichconcreteispoured• thesupportstowithstandtheloadsimposedbytheforms and concrete• anybracingaddedtoensurestability.

Hazardsassociatedwiththeerection,alterationordismantlingofformwork include:

• fallsfromheight• fallingobjects• formworkcollapse(before,duringandafterpouringofconcrete)• slipsandtrips• noise• dust• manualtasks• sharpedgesonmetaldecks• sunglare.

Toproperlymanagerisks,apersonmust:

• identifyhazards• assessrisksthatmayresultbecauseofthehazards• decideoncontrolmeasurestoprevent,orminimise, the level of risk• implementthecontrolmeasures• monitorandreviewtheeffectivenessofthosemeasures.

Controlmeasuresmustbeimplementedinanorderofpriorityandbeforeworkcommences.Figure1belowillustratesthehierarchyof controls which represents the order of priority for controls where there is a risk that a person could fall.

1.1 fAlls from HeIgHT – lImITATIons of HArness sysTems for formWork AcTIvITy

Whenerecting,alteringordismantlingformwork,theuseofthefollowing systems is not recommended:

• travelrestraintharnesssystemstopreventafall• fallarrestharnesssystemstoarrestafall.

Travel restraint harness systems are impractical for formwork as:

• thecontouroftheleadingedgeisconstantlychanging,requiring the length of the travel restraint line to be continually adjusted• multiplelanyardanchoragepointsmayberequired• thegreaterthenumberofworkersbuildingtheformworkdeck, the greater the likelihood of lines becoming tangled.

Fall arrest systemsareprohibitedundertheSouthAustralianOccupational Health, Safety and Welfare Regulations 2010(OHSWRegulations)insituationswherethereisinsufficientdistanceavailabletopreventapersonhittinganobject,thegroundoranothersurface,otherthanaverticalsurface.Forexample:

• Whenerecting,alteringordismantlingformwork,theremaybe insufficientfreefalldistanceunderneaththeworkingarea, resultinginafallingpersonstrikingtheground,aframeorother obstruction prior to the fall being arrested.• Afallingpersonmayrequireafreefalldistanceinexcessof 6mforthefalltobesafelyarrestedbyaharnesssystem.In somesituations,thisdistancecanbesubstantiallyreducedby the use of shorter lanyards and/or higher anchorage points.• Theanchoragepointdesignloadrequiredforfallarrestsystems isrelativelyhigh.TheOHSWRegulationsspecifythateach anchorage point of the system must have a minimum capacity of 15kNforonepersonfree-falling.• Theerectionofformworkframesusingfallarrestharnesses requires the user to regularly disconnect from and reconnect to anchoragepoints,requiringtheuseofadoublelanyard.

Figure 1 Hierarchy of controls – Controlling the risk of falls

Design and planningEliminatetheriskduring the design and planning stage.

When this is not practicable, use level 1 controls:Workonasolidconstructionwithsafeaccess/egress,edgeprotection,openingscoveredetc.

When this is not practicable, use level 2 controls:Usefallpreventionsystemse.g.temporaryworkplatforms,scaffolds,perimeterguardrails,elevating work platforms.

When this is not practicable, use level 3, thenlevel4orfinally,level5controls:level 3–useworkpositioningsystems,travel restraint systemslevel 4–usefallarrestorcatchplatformslevel 5–useladdersoradministrationcontrolse.g.nogoareas,permitsystems,safe work systems.

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consider the following before using a harness system:

• Ariskassessmentaddressingthehierarchyofcontrolsshouldbe usedtoidentifysatisfactoryalternativestoaharness–basedon fall prevention measures.• Implementingtheuseofsolidworkzonebarriersisone effectiveengineeringsolution.Refertosection4.1.7ofthisguide for further information.• Trainingisrequiredbeforeapersonusesaharness.Fortraining requirementsundertheSouthAustralianOccupational Health, Safety and Welfare Act 1986(OHSWAct),pleasereferto Appendix2.

2. Design

Undersection23a‘Dutiesofdesignersandownersofbuildings’oftheOHSWAct,designersofbuildingstobeusedasworkplaceshaveobligations for workplace health and safety.

2.1 sAfe DesIgn of buIlDIngs In relATIon To formWork

2.1.1 ‘buildability’

Buildingdesigners,includingengineersandarchitects,mustconsiderthe‘buildability’ofastructureorbuildingwiththeobjectiveof producing a design that minimises the risk of injury during construction.

Thedesignofthefinalconcretestructuremayhaveamajoreffectontheeaseofformworkconstructionandconsequently,onthesafetyofpeopleduringconstruction.Generally,amorebasicandsimplefinalconcrete structure is safer to erect.

Aformworkdesignershouldbeconsultedduringthedesignofanybuilding to provide input on ways to minimise the risk of injury arising from formwork activities.

The following design measures could be considered to minimise exposure to risk of injury during the construction of formwork:

• Reducevariationsinthefloordepthi.e.constructafloorso that it has one consistent depth. Decks that are a consistent depthareeasiertoerectthanvariabledepthfloorsandreduce theriskofinjury.Deeperbeamsintroduce‘dropdowns’into thefloor,creatingtripandfallhazards,andrequiremoreworkto construct and strip after pouring.• Wherebeamformsareessential,lightweighttemporaryaccess across the beam recess must be provided to prevent injury to workersfromsteppingintotheformduringconstruction(see Figure2above).• Reducethenumberofcolumnsrequiredandwherecolumnsdo exist,eliminatecapitalsanddropdowns.• Utiliseprecastcolumnsandbeams.Thiscanreducetherisks associatedwithfixingreinforcement,erectingandstripping columnformworkandpouringconcreteon-site.Workactivities carried out in a factory environment are generally lower risk.

• Reducecantileveredfloorsections.• Planformanualtasks.Considerationshouldbegiventothe suitability of the design of different formwork systems that will reduce manual handling risks such as: - table forms - systems with lighter weights of materials to be handled - methodsofformworkerection,alterationanddismantling - improved access and egress for workers and movement of materials and equipment - methodsformovinglargeandheavycomponents,materials and equipment i.e. making allowances for a crane and other mechanical lifting devices to be used. 2.1.2 materials

Allmaterialsandequipmentusedinformworkconstructionmustbefitfortheintendedpurpose,meetdesignspecificationsandbedesignedtoconformtorelevantAustralianStandards.Equipmentmust be manufactured in accordance with a quality assurance systemthatensurescompliancewiththedesignspecification.

EvidenceverifyingthatformplysheetsandtimberbearersconformtoAustralianStandardsshouldbekepton-site.Suchevidencemayinclude:

• apurchaseorderwhichdetailsthespecificationsofthe form ply sheets ordered• formplysheetsbeingmarkedinaccordancewithAustralian Standards(seeAS/NZS 2269.0:2008 Plywood-Structural- Specification).

Figure 2 – Flat floor and temporary access asfall protection for deep floor beams

 

 

Fig.  2.  –  Flat  floor  and  temporary  access  as  fall  protection  for  deep  floor  beams  

 

 

 

Fig.  2.  –  Flat  floor  and  temporary  access  as  fall  protection  for  deep  floor  beams  

 

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Ifalternativeproducts,otherthantimberareused,anengineershould verify that they are adequate for purpose.

2.2 formWork sysTems

InAustralia,formworksystemsaregenerallydesignedto:

• AS 3610 – Formwork for Concrete • AS 3600 – 2009 Concrete Structures.

2.2.1 Safeformworkdesignandverification

Adesignerofformwork,eitheraformworkdesigneroranengineer(seeAppendix1fordefinitions),isresponsibleforoverseeingthesafe design of the complete formwork structure. This includes designoftheformworksupportstructure,theformworkdeckandconnection details.

Whenspecifyingthedesignoftheformworksystem,aformworkdesigner must allow for all expected loads applied during the three phasesofconstructioni.e.duringformworkerection,duringconcretepouring and after concrete pouring is complete until the structure is self-supporting. This includes loads applied by:

• theformworkdeck,supportingmembersandformworkframes• anyfalsedecksthatmaybeprovided• concretepouringtechniques(i.e.concreteskiporpump)• theconcretepour,whichincludesboththeweightofthe concreteanddynamicfactorsapplied,includingtheconcrete pour rate and pour sequence• workersontheformworkdeckandfalsedecks• stackedmaterials• crane-liftedmaterialsonboththecompleteandincomplete formwork deck• environmentalloads,includingforcesduetowaterflowing aroundtheformwork.Rainandrunoffcanhaveadetrimental effect if not considered by a designer• wind,asdetailedinAS 1170.2:2011 Structural Design Actions – Wind Actions: − wind loading will vary depending on: - thesizeofform - the nature of the form - wind speed - windresistance(e.g.screens) - wind direction − windloadingonverticalforms,particularlyforexternalwalls, columns,freestandingshutters,bladewallsandany platforms that may be subject to uplift − vertical elements should be fully braced prior to and during stripping until such time as the construction provides adequate support against wind loading − shadeclothusedonscreens,signageandoutsidescreens will increase the effective wind loading of an open structure

− the geographical location of the construction site will have a bearingontheseverityofwindonthestructure.Wind generally has less effect in built up or hilly areas − AS 1170.2 Structural Design Actions – Wind Actions specifiesfourdifferentterraincategoriesthatshouldbe taken into consideration by a formwork designer as well asbasicwindspeedsfordifferentzonesinAustralia [practicallyallareasofSouthAustraliafallunderRegionA (normal)].

Refertosection4‘StructuralDesignandDocumentation’ofAS 3610 Formwork for Concrete for further details on formwork load calculations.

2.2.2 Formworkdesigncertificationrequirements

This guide considers two types of formwork systems: basic and non-basic.Aformworkdesignermaycertifyabasicformworksystem,whereasonlyanengineermaycertifyanon-basicformworksystem.

Whilethisguiderecommendsthatonlyanengineermaycertifyanon-basicformworksystem,itisrecognisedthatacompetentpersonexperiencedinformworkdesignanddocumentation,suchasaformworkdesigner,mayperformthemajorityofthedesignwork.

Forbothbasicandnon-basicformworksystems,certificationshouldconfirmthattheformworkmeetstherequirementsofAS 3610 – 1995 Formwork for Concrete and the construction drawings. This certificationshouldalsoconfirmthatotherformworkandprojectdocumentationdetailedinsections2.2.3ofthisguide,havebeencompletedasrequiredfortheproject.Sampleengineer’scertificationlettersareprovidedinAppendix3.

basic formwork systems

Forthepurposesofthisguide,abasicformworksystemistheformworkforafloor,wallorcolumnandincludes:

• standardformworkframeswhichhaveaknowntestedloading capacity and are spaced at no more than the recommended distancesapartforanormalfloorthicknesswithbearers,joists and form board on top of them• speciallymanufacturedanddesignedformworksystemswith proprietary formwork components and rated load calculations in linewiththemanufacturers’specifications.

Abasicformworksystemislimitedbythefollowingconditions:

• theheightoftheformworkmaybeuptoamaximumof6mto thesoffitofthenewfloorfromthesupportingfloor• wallsandcolumnsmaynotbegreaterthan6mfreestanding fromtheflooronwhichtheformworkwillbesupportedtothetop surface of the concrete• anyback-proppingisexcludedfrombasicformworksystemsand istobecertifiedbyanengineer.

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Eitheraformworkdesignerorengineermaycertifyabasicformworksystem.Whereanyoftheseconditionsareexceededorback-proppingisinvolved,thesystemistobeclassifiedasanon-basicformworksystemandmustbecertifiedbyanengineer.

non-basic formwork systems

Formworksystemsthatexceedthedescriptionofabasicformworksystemare,forthepurposesofthisguide,categorisedasnon-basicformworksystems.Forthepurposesofthisguide,onlyanengineermay certify:

• thedesignofanytemporaryorpermanentformworkstructures categorised as non-basic formwork systems • anyback-proppingusedforeitherbasicornon-basic formwork systems.

Non-basicformworksystemsincludeformworkstructuresforanyfloor,wallorcolumnhigherthan6m,orthreeframes,orthreetimesthe least base width of the scaffold.

2.2.3 Documentation

The extent of documentation required for any structure may vary depending on the complexity of the formwork and supporting structure design and the conditions in which it is to be constructed. The documentation requirements outlined below are provided as aguideonly,forsituationswherethereisacomplexconstructionprocessatheight,thatisconsideredtobehighrisk.Itisexpectedthat some elements of documentation may be reduced or omitted for some more basic and lower risk construction applications.

formwork drawings

Formworkdrawingsexplainthegeneralarrangementoftheformworkplans,elevationsandsections,identifyingandlocatingallmembersand components including bracing.

Anengineershouldnominatethefollowingonthedrawingsorotherdocumentation:

• maximumallowablepointloadingtobeappliedandany additionalproppingrequirementsatanyspecificloadingarea• componenttypesandspacing• maximumjackextensions• bearerandjoisttimbertype,dimensionsandspacing• propsizesandmaximumextensions• methodsfortyingthestructuretogetherandspacingbetween ties(ifrequired)• formplysize,thicknessandgrade.

Whereeccentricloadingistobeappliedto‘U-heads’(i.e.singlebearersarepositionedtoonesideoftheU-head),theformworkdrawings must state that this is permitted.

other formwork documentation

The following information should be included in the formwork documentation:

• anynecessarypreparationofthefoundationsuchasfilling, compaction and drainage• anyfootingdesignassumptions,suchasfoundationmaterial description,safebearingvalues,limitationsonsettlementduring erectionofformwork,placementofconcreteanddismantlingof formwork.Referencetoinformationsourcessuchas geotechnical reports may also be included• footingdetails,suchastypeandsizeoffootings,levelofsoffit, concretemixdesignstrength,reinforcement,specification anddetailsofsitefillingorcompaction,andprecautionsagainst washouts• sufficientdetailstofullydescribeimportantorunusualfeatures oftheformworksystemdesign,includingdesignassumptions, particularlythoserelatingtostrength,stabilityandstiffness• theareasoftheformsdesignedtocarrystackedloads,together withthemaximumallowableload,andtheminimumstrengthof concrete to be achieved prior to materials being stacked• Safeworkmethodstatementsaddressing: − the erection and stripping of the formwork assembly − methods for securing single or multiple props − methodsforfieldadjustmentoftheformspriortoand during concrete placement − verticalpourratesinmetresriseperhour,includingtherisks and implications of exceeding vertical pour rates − sequenceofconcreteplacement,includingdirectionof intendedpouronrakingorslopingsurfaces(e.g.carpark ramps and minimum elapsed time between adjacent placements) − wrecking strips and other details relating to stripping of the forms• certificationofnon-proprietaryequipment• referencetodocumentationforproprietaryitems• whererequired,locationofweepholes,vibratorholes,clean-out holes and inspection openings• acceptancecriteriaforsingleuseformwork.

Project documentation

Otherprojectdocumentationshouldincludethefollowinginformation:

• detailsoffallandedgeprotectioni.e.perimeterscaffolding• locationofanymandatoryjointsandanyspecialproceduresfor locating other joints• detailsofanyinserts,waterstops,speciallyformedshapesor penetrationstobeconstructed,thelocationanddetailsofwhich are critical to the serviceability of the permanent structure• informationonanyarchitecturalorstructuralcomponentdetails to be cast into the structural concrete

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• detailsofthecamberingofanyslabsorbeams• informationaboutanypermanentformworksystems,together withlimitationsondeflectionsandanyspecialrequirementsfor their erection and concreting• limitationsontheuseofthepermanentstructurefortherestraint of formwork• minimumstrippingstrengthortimes,strippingproceduresand requirements for health and safety• detailedinformationontheeffectofpreorpost-tensioning procedures on the formwork and any special procedures to be adopted in the stripping of formwork• detailsofback-proppingthatmayberequiredandminimum timeintervalsbetweenconcretepours,includingrequirements for propping of any composite construction• requirementsfortheminimumnumberoflevelsofsupports relativetothetypeofformwork,thetimingandsequenceof floorpropping,andtheanticipatedtimebetweenconstructionof subsequentfloorsformultistoreystructures.

2.2.4 Design variations

Allformworksystemdesignvariationsmustbecheckedbyaformworkdesignerforabasicsystem,oranengineerforanon-basicsystem.Thevariationsmustbecertified(inwriting)ascomplyingwith AS 3610 – Formwork for Concrete or whether they need to be altered in accordance with written directions to comply with AS 3610.

Potentialvariationsmayinclude:

• thenumberofformworkframesundertheformworkdeck• typesandnumberofbracesorpropsotherthanindicatedon the formwork drawing• typesand/orquantitiesoftiesontheformworkstructure• spansonmemberssupportingtheformworkdeck• back-proppingsystemsspecifiedbyanengineer• connectionsbetweentraditionalformworkand modular formwork.

2.2.5 On-sitecoordinationandverification

Complexprojectsrequireconstantandvigilantcoordinationbyanexperiencedmanagementandsupervisoryteam.Withproperlyscheduledandcoordinatedactivities,sub-contractorsareabletocarryouttheworkinanorderly,safe,andmoreproductiveway.

Effectivecoordinationandtechnicalaccuracyalsorequirethatformwork,projectandvariationdocumentationarereadilyaccessibleon-site.

Wheneffectivesitecoordinationisnotimplementedoraconstructionteamdoesnothaveaccesstoessentialtechnicalinformation,thepotential for failure increases.

Verificationoftheformworkstructure

Aneffectivequalitycontrolsystemmustbeimplementedfortheconstruction of formwork. The system should ensure that:

• materialsandcomponentsusedon-sitecomplywiththeformwork designspecifications,drawingsanddocumentation• damagedorexcessivelywornmaterialsandcomponentsarenot used,butareidentifiedandsentoff-siteforrepairoraredestroyed.

Theformworkstructure’scompliancewithitsdesignmustbeverifiedanddocumented.Aconstructionchecklistmaybeusedasaguideforthisprocess(refertoAppendix4forasamplechecklist).However,relying solely on a checklist does not necessarily verify compliance with relevantAustralianStandards.

Thedesignverificationanddocumentationprocessmaybedelegatedtoa‘competentperson’who,ifnotanengineerorformworkdesigner,musthavetheexperience,trainingandknowledgetoperformon-siteinspectionsoftheformworksystem(refertoAppendix1fordefinitions).

The competent person must be:

• experiencedinformworkconstruction• competentininterpretingdrawings• abletocertifythattheformworkstructuresatisfiesthedetails ontheformworkdrawings,specificationsandanyotherformwork documentation.

Shouldthecompetentpersonon-sitenotbeaformworkdesigneroranengineer,thecompetentperson:

• mayonlyverifythattheformworkstructurecomplieswiththe designer’sspecificationsanddrawings• maynotauthorisevariationstothedesign• mustprovideanyconstructionchecklistreferralstoanengineer in writing• mustprovidewritteninstructionstotheformworksupervisorfor any remedial actions that need to made to the formwork system prior to the concrete pour• mustensurethatanyremedialactionrequiredhasoccurredprior totheconcretepour,includinganyitemsreferredtoanengineer.

Pre-pourinspectionmustfocusonsuchmattersas:

• thelatestversionofstructuralandformworkarrangement drawings and details submitted• correctspacingofframes,propsandtimbers• correctjoistandbearersizes,andloading• acceptablejackextensions• adequatebracingtoensurestability.

Pre-pourinspectionsarethelastreasonableopportunitytoensurecompliancewiththeformworkdesignspecifications.Suchinspectionrecords form an important part of the site quality control system and mustbesigned-offbyanengineer,formworkdesignerorcompetentpersonfollowingthefinalpre-pourinspection.Asamplepre-pourstructuralinspectioncertificateisprovidedatAppendix5.

common defects in formwork systems

Appendix6illustratessomeofthemorecommondefectsthatare likely to occur in a formwork system. The list is intended to

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give guidance to a competent person and is not considered to be exhaustive.Inanyindividualcase,theimportanceofitemsmayvaryand only a competent person can assess their relative importance.

3. coordination and administration 3.1 Work ProgrAm

Therisktoaperson’shealthandsafetymustbeconsideredwhendesigningaworkprogramforerecting,alteringordismantlingformwork.Considerationshouldbegivento:

• edgeprotectionrequirementsandensuringthesearedesigned and constructed in a timely manner to be safe to use• sequencingworktoensurethatsufficienttimeandresources are allowed for each work activity• coordinatingtradestoallowworktobecompletedfreefrom obstruction.

3.2 HousekeePIng – Access AnD sTorAge

Formworkconstructionresultsinaconstantlychangingworkenvironment,withrestrictedaccessthroughframesandformworksupports,oftenwithlargevolumesofmaterialandwaste.Forthisreason,itrequiresongoingmonitoringofhousekeepingpracticestomaintain a safe and productive workplace.

Include housekeeping as an essential aspect of every job whether itbethroughworkinstructions,regularinspectionoftheworkplace,or site/task induction training. Instructions should include time and resources for the progressive clean up of work areas to prevent rubbishandredundantmaterialsfrombecomingatriphazardandtoallow safe access for mechanical aids.

3.2.1 Access and egress

TheOHSWRegulationsrequirethattherebeclearaccesstoandfromtheworkplaceinaccordancewithDivision1–Accessand egress.

Clearaccessisimportantforthesafemovementofmaterials,equipment and anyone on-site. Designated access ways should be providedandanyoneon-siteshouldbedirectedtousethem.Accesswaysmustbekeptclearofanyrubbish,plantormaterials.

Insomesituations,greenhazardtaping/buntingorothervisualmethods can clearly show where access ways are located. This is particularly important where access is required through formwork frames.

Emergencyaccessandegressmustbeprovidedtoallpartsoftheworkplace. The following situations should be considered:

• stretcheraccessandegress• peoplecarryingtoolsandequipment• useofstairs• provisionoftwomeansofegressatalltimes.

3.2.2 material storage

TheOHSWRegulationsrequiresafestackingandstorageofplantandmaterialsataworkplace,asdetailedinDivision15–Storage.

Materialsmustbestoredinawaythatminimisesmanualtaskhazards,triphazardsandthepotentialforhazardsfromfallingobjects.SmallercomponentssuchasU-heads,couplers,baseplatesand‘Z-bars’shouldbestoredinlabelledmaterialboxes,markedwithsafeloadlimits(SLL).

Wherepracticable,frames,formplysheets,bearersandjoistsshould be strapped in bundles or stacks and be located away from theedgeofthedeck,topreventmaterialsoranyoneaccessingthemfrom falling.

Wallformsshouldbestackedinsuchawaythattheycannotslide,orrotateawayfromthesurfacetheyareplacedagainst.Anengineershouldverify,inwriting,thatasurfacetobeusedforstackingformsiscapableofwithstandingtheimpactofallimposedloads,includingwindloading.Ifpurpose-made‘A-frames’arenotavailableforstoringwallformswhennotinuse,itispreferabletolaythemflatontheground,ratherthanleaningthemagainstotherstructures.Timbers,orothereffectivemeansofsupport,shouldbeusedunderforms where slings are to be used for lifting.

3.2.3 rubbish storage and removal

Rubbishstorageandremovalforformworkmayincludetheprovision of rubbish skips and wheelbarrows that are moved as work progresses.However,rubbishskipsmayonlybepositionedwherethe supporting structure has adequate strength to support the total weight of the bin and its likely contents.

3.2.4 storage to minimise manual task risks

Incorrect material delivery and storage practices can create significantmanualhandlingrisks.Safeworkpracticesthatcanassistin minimising these risks include:

• ensuringthatformworkmaterialsaredeliveredascloseas practicable to the job• designinganddesignatingasmallsectionoftheformworkdeck as a loading platform for ply and other components• ensuringmechanicalaidsareusedtohandleloadswherever possible• storingloadsontrolleystominimisedoublehandling,oron raised platforms to minimise manual lifting from ground level• havinganadequatestoragespaceorlaydownareastosafely store materials/equipment and to minimise double handling.

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3.3 TrAInIng

Anyonewhomaybeexposedtoworkplacehealthandsafetyrisks resulting from formwork construction must be provided with informationandtrainingthatisspecifictotheformworksystemthatis being used. Training and information should include details of:

• theformworksystem,components,tasksandactivities• thewaythemanufacturerordesigneroftheformworksystem intendedittobeerected,installed,used,moved,alteredor dismantled• therangeofhazardsassociatedwiththeformworksystem, controlmeasurestominimiseexposuretotherisks,thecorrect use of controls and how to ensure controls are maintained• anyspecialrequirementstoundertakeorparticipateinspecific tasks or activities• anysafeworkmethodstatements,includingtheuseof mechanical aids and devices • theuseandmaintenanceofequipment,includinganyspecific conditionsandprohibitionsonitsuse.Wherenecessary, referenceshouldbemadetooperator’smanuals• anyspecialsafetyinformationneeded,suchassafety precautions for working under certain conditions including hot workorconfinedspacework• personalprotectiveequipmentrequirements,including instructionsforfitting,use,cleaning,maintenanceandstorage• theavailabilityandcontentofthisindustryguidancedocument.

FortrainingdetailsrefertoAppendix2.

4. Work systems4.1 formWork erecTIon – TrADITIonAl sysTems

TheOHSWRegulationsdescribewhatmustbedonewherethereisariskapersoncouldfallinDivision13–PreventionofFalls.Thelegislationalsorequiresthatahazardidentificationandriskassessmentbeconductedand,wherenecessary,safeworkmethodstatements documented.

Formworkactivitiesmustcomplywithregulatoryrequirementsfortheerectionofscaffolding.Formwork,likescaffolding,mustbeerectedsafelyandsystematically,andbetiedinprogressivelytostabilise the structure.

Apersonmustbeprovidedwithaworkingplatformatleast450mmwide(i.e.twoplanks)evenwhenthepotentialfalldistanceis less than 2 m. It is not acceptable for a person to work from a single plank or bearer.

Irrespectiveofwhichframingsystemisused,workersmustalwaysuse working platforms that are two planks wide as a minimum.Whereapersonistoinstalljoists,thiscanbeachievedusingatwo-plankworkplatformfromunderneath,allowingtheverticaldistancebetween the formwork deck and the false deck to be increased. This isillustratedinFigure3below.

 

Fig.  3  –  Worker  erecting  formwork  on  two  planks  

VARIABLE  

Figure 3 – Worker erecting formwork on two planks

>2.0 m

vArIAble

<2.0 m

11

4.1.1 foundations

Formworkmustbeerectedonastablebasetopreventtheriskofcollapse.Suspendedslabsmustbeabletosafelysupportloadsthatmaybeappliedbytheconcretepour,workersandcrane-liftedloads etc.

Baseplatesmustbeprovidedunderpropsandstandardsonformworkframesunlesstheproporstandardhasanintegralfoot,oran engineer documents that a base plate is unnecessary.

Soleboardsdesignedtosuitthegroundconditionsmustalsobeusedunderpropsandstandardsonnaturalground,unlessanengineerstatesotherwise.Framesandpropsmustbelocatedonasoundbasethatwillnotsubside,failorwashaway.Theprincipalcontractor is responsible for providing all information on ground conditions to the engineer or formwork designer.

4.1.2 false deck

In situations where a deck is being installed at a height that would require a person to stand at a height of 2 m or more to install bearers andjoists,acontinuous‘falsedeck’shouldbeprovided(seeFigure4below).Thisisafulldeckthatisthesameareaasthefloorbeingformedbutupto2mbelowthetruedeck.Asindicatedinsection4.1above,thedistancebetweenthefalsedeckandthetruedeckcanbeincreasedwhereaworkplatformisused.However,thefalldistancefrom the work platform to the false deck must not exceed 2 m.

The false deck should be continuous both inside and between formworkframesandtypicallyconsistsofformply,scaffoldplanksormodularplatformsections.Aprotectedaccessopeningcanbeleftinthe deck for lifting in materials.

The use of a captive platform is preferable to lapped planks because a captive system cannot be accidentally dislodged and its constructionalsominimisestriphazards.Lappedplanksmayonlybe used if they are secured against uplift and slippage. The false deckshouldbeconstructedsuchthatnogapexceeds225mminwidth and gaps only exist where a vertical member of a frame passes through the deck.

The false deck should be designed to have adequate strength to support:

• anyonerequiredtostandonthedeck• materialsthatneedtobeonthedeck• anymaterialsorworkersthatshouldhappentofall.

The deck must be able to withstand:

• apointloadof2kNdistributedoveranareaof100x100mm (2kNisapproximatelyequivalenttoamassof200kg)• auniformlydistributedloadof2kPa,whichisequivalenttoa mass of 200 kg per m2.

Whenconsideringthedesignofthedeckforerecting,alteringordismantlingformwork,theweightofthefalsedeckandanyadditionallive loads must be applied to the analysis of the formwork support structure.

The height between the false deck and the pouring deck should allow comfortable access for a person during stripping.

4.1.3 erecting frames

Anyoneinvolvedinerectingformworkframesmustbetrainedtodothissafely.Apersonsupervisingtheerectionofformworkframesystemsmustbeacompetentperson(asdefinedinAppendix1).

TheOHSWRegulationsprovidetherequirementsfortrainingandresponsibilities of workers performing a class of high risk work.

In cases where scaffold equipment is used as a formwork support structureanditispossibleforapersonorobjecttofall4mormorefromthescaffold,theOHSWRegulationsrequireapersontohold:

• aBasicScaffoldinglicence(SB)toerectproprietaryframes or• anIntermediateScaffoldinglicence(SI)toerecttubeand fittingscaffold.

Traineesarepermittedtoperformscaffoldwork,providedtheyareunder the direct supervision of a competent person who holds the scaffolding licence necessary for the task.

Formworkframesshouldbeerectedinaprogressivemannertoensureboththeinstaller’ssafetyandthestabilityoftheoverallstructure.Bracingistobeattachedtotheframesassoonaspracticable. The risk of a fall from edges of formwork frames during theirerectionishigh.Inthissituation,itisnecessarytoinstalledgeprotection on the frames as they are erected.

Conventionalformworkframesincludediagonallyhingedbracesthatcrossinthemiddle.Whilethesebracesarenotconsideredtobesuitableedgeprotectionforacompletedformworkdeck,basedonariskassessment,theymayprovidereasonablefallprotectionduringframeerection.Suchfallprotectionexistsonlywhenbracesareinstalledimmediately,andinaprogressivemanner.

Fig. 4 – A false deck

Figure 4 – A false deck

Gap not to exceed 225 mm

12

Astheheightofformworkframesincreases,thereisagreaterneedtoprovidelateralstabilitytotheframestructure.Allframingmustbecarried out so that it complies with on-site design documentation and anymanufacturer’srequirements.

4.1.4 Installing bearers

Whenpositioningbearers,installersmustbelocatednomorethan2mfromthefloororthefallarrestingplatformlocatedimmediatelybelowthem.Forexample,bearerscanbeliftedontothetopoftheformwork frame by a person standing on a work platform erected withintheframeandnomorethan2mfromthefloororfalsedecklocatedimmediatelybelow(seeFigure5below).

Bearersmustbepositionedsuchthattheywillnotfallfromtheframes. The common methods of ensuring this are to place the bearersinU-headsontopoftheframesandalsobyensuringcantileversareminimised.WhereonlysinglebearersareplacedintheU-head,thebearermustbeplacedandfixedcentrallyintheU-headunlessaformworkdesignerorengineerstatesotherwise. 4.1.5 Installing joists

Whereafalsedeckisprovidedat2morlessbelowformworklevel,joists may be spread on the bearers with the worker standing on the false deck. If the height of the formwork deck being constructed is morethan2maboveacontinuousdeckorsurface,joistsmustbespreadfromaworkplatform,atleasttwoplankswide,andlocatedwithin 2 m of the surface underneath the deck being constructed (refertoFigure5).

Oneexampleofaworksystemthatmaybeusedtodothisisas follows:

The joists are lifted by the workers and spread on top of the bearers into their approximate final positions whilst standing on a lower work platform. The platform below the deck must be positioned at a comfortable height for handling joists (without introducing manual task risks) and not greater than 2 m from the false deck.

4.1.6 fall protection from the formwork deck

Continualmodificationoffallprotectionmeasuresisnecessaryduring formwork construction because the structure is constantly changing.Oneofthebiggestchallengesistoprovideadequatefallprotection on the leading edge of the formwork deck.

Wherethereisonlyoneleadingedge(i.e.theotheredgesareprovidedwithscaffoldingedgeprotection),theprovisionoffallprotectionisrelativelystraightforward.However,wheretherearemultiple leading edges and/or the deck is not at one consistent level,theprovisionoffallprotectioncanbedifficulttoimplement.Designersofbuildingsarethereforeencouragedtodesignfloorslabsthatareoneconsistentthickness(refertosection2.1.1‘Buildability’).

Leadingedgeandperimeterprotectionmustbeprovidedonedgeswhere the potential fall distance is 2 m or more and a person is not preventedfrombeingwithin1.8moftheedge.Controlmeasuresarerequiredwhereapersoncouldfall,fromanyheight,ontoanobjectsuchasframes,reinforcingsteelorarubbishskip.

 

 Fig  5  –  Setting  U-­‐heads,  bearers  &  joists  

 from  a  two-­‐plank  platform  

 

>2.0m  

   

<2.0m  

   

Figure 5 – Setting U-heads, bearers and joists from a two-plank platform

<2.0 m

>2.0 m

 

 Fig  5  –  Setting  U-­‐heads,  bearers  &  joists  

 from  a  two-­‐plank  platform  

 

>2.0m  

   

<2.0m  

   

 

 Fig  5  –  Setting  U-­‐heads,  bearers  &  joists  

 from  a  two-­‐plank  platform  

 

>2.0m  

   

<2.0m  

   

13

4.1.7 edge protection on the formwork deck

4.1.7.1 formwork construction zone physical barriers

Aphysicalbarriershouldbeprovidedandmaintainedtoseparatetheformworkworkzonefromotherworkers.Thisbarriermustberigid,capable of maintaining its integrity in an upright position and capable ofsupportingsignageifrequired(seeFigures6aand6babove).

The use of flags and tape or unsupported barriers is not acceptable.

Wherethedesignoftheformworkiscomplexandtheprofileofthedeckisconstantlychanging,constructionofleadingedgeprotectionmaycreatemorehazardsthanitwouldcontrol.Insuchcases,itmaybeimpracticaltoprovideedgeprotection,asanyoneinstalling the edge protection would be exposed to the risk of falls. In some situations perimeter edge protection must be installed. Examplesinclude:

• wherethereisachangeindeckheightalongthesideofthedeck beingconstructed,(i.e.adropdownforabeam)andnojoistsor form ply have yet been installed at this different height• wherealeadingedgeistobeleftunattendedandaccessonto thedeckisrequiredbyanyoneotherthanformworkers(i.e.the formwork deck has not been barricaded off and marked with ‘keepout’signs).

4.1.7.2 edge protection on completed decks

The most effective means of providing edge protection on a completed formwork deck is to install perimeter scaffolding.

Scaffoldingiserectedpriortotheformworkand,therefore,prevents workers falling from the completed deck. The advantages ofthissystemarethatedgeprotectionforinstallersofthefinalperimeterformplysheetsisalreadyinplace,thereisnorequirementtoinstalledgeprotectionontheperimeter,andnoexposuretoariskof falling.

Insomeraresituations,itmaybeimpracticaltoprovideperimeterscaffolding.Insuchcases,edgeprotectionmustbeinstalledandthework system used for this installation must include a control measure against the risk of a fall.

Theuseofharnesssystemsisdiscouraged,becauseitdoesnot provide an adequate level of protection from injury and is an impractical control for the risk of a fall from height in formwork erection(refertosection1.1ofthisguide).

Insomesituations,edgeprotectioncanbesubstitutedwithanalternativemeasure,providedthismeasurepreventsapersonfallingfromtheedge.Onealternativeistheprovisionofabarricade,1.8mfromtheedgewithclearlyvisible‘keepout’signs.

Furtherguidanceonstanchions,guardrails(handrails)andmidrailsforminimumstrengthandrigidityisspecifiedinAS 1657 Fixed platforms, walkways, stairways and ladders – Design, construction and installation.

Wherescaffoldingisover4minheight,onlylicensedandauthorisedscaffoldersmayerect,dismantleoralterthescaffolding.Anyscaffolding components that are temporarily removed must be replacedattheearliestopportunity.Anygapsbetweenacompletedfloorandscaffolding,thatmayexistaftertheformworksupportsystemisremoved,mustbecoveredwherethereisariskofaperson or materials falling through.

4.1.8 laying a formwork deck

4.1.8.1 getting started – safe access

Afterthesupportingframes,bearersandjoistsareinposition,thefirstessentialconsiderationinlayingaformworkdeckisthatallbuilding work conducted at height requires some type of perimeter protection.Thesecondessentialconsiderationisthat,forfallprevention,workersmuststayawayfromaleadingedge.Howtheseessential elements are achieved is determined by the builder.

Figure 6a – General view Figure 6b – Fixing detail

Acceptable solid work zone barrier with ‘No-Go’ zone below

14

Thefirststepinlayingoutaformworkdeckistoprovidesafeaccessandaheavydutybaytoloadandstorematerials,particularlyapackofformply,attheformheight.Successfulsolutionswillbepartiallyguidedbythesiteitself,thesizeofthejoborthecontractor’spreferredsystem,andmaybeanengineeredsolution,ascaffoldsolutionoraformworksupportsystemsolution.Eachhasadvantagesand disadvantages.

engineered solutions

Generally,engineeredsolutionsareeconomicaltoassemble,disassemble,useandmaintain,andmaybedesignedforahigherload-carryingcapacity(withsufficientsupportframecapacity).Theyare more suitable for larger projects with more site room.

Engineereddeckunitsarepositionedandliftedbymechanicalaids,suchasmulti-purposetoolcarrier,forkliftorcrane,thusreducing the risk of injury from manual tasks. Drop-in hand railing systemsareeasilyinstalledatgroundlevel,reducingtheriskoffallsduring erection.

However,engineeredsolutionsgenerallyhaveahighercapitalcosttodevelop,manufactureorpurchase.Engineeredsolutionsarelessflexiblebecausetheremustbeaclearaccesswayof450mm.Thislimitsavailablespaceforstorageofmaterialsonthedeck(seeFigure7below).

scaffold solutions

Scaffoldsolutionsmaybemoreflexibleintheirarrangementandwould normally require a lower initial capital investment than engineered solutions. They are generally more suitable for smaller jobsandrestrictedsites.Scaffoldsystemloadingbaysaremanuallyerected,withtheplatformareaandhandrailsbeinginstalledatheight,increasingtheriskoffallsduringerection.

The load carrying capacity of scaffold-based systems is generally lowerthanengineeredsolutions,beingheldwithintheallowablelimits for AS/NZS 1576.1:2010 Scaffolding Part 1: General Requirements.However,scaffoldingmaybespecificallydesignedforhigherloads.WorkplatformsdesignedforhigherloadsmustprominentlydisplayasignindicatingtheSLL.

Scaffold-basedsystemsaregenerallymoreadaptableinallowingforincreasedsizeofstoreditems,notnecessarilybeinglimitedtothesizerequirementsof2400x1800mmformplysheets,whilstmaintainingthenecessary600mmminimumaccesswidth.

formwork support system solutions

Packsofformplysheetsmaybeplaceddirectlyonthejoistsofaformworksupportsystemundercertaincircumstances.Asectionof the formwork support system may be a nominated loading area providing:

• thenominatedloadingareaiscertifiedbytheengineeror formwork designer• themaximumSLLoftheareaismarkedontheformwork drawings,togetherwithadditionalproppingrequirements

Figure 7 – Engineered loading bay.Note: Drop-in handrails in place, lifting eyes, forklift slots, and built-in bearers

15

• anynecessaryadditionalpropsareinstalledandinspectedprior to loading• aperimeterscaffoldisinplaceforfallprotection• theloadingareaissafelyaccessiblefromaperimeterscaffoldor other safe access structure• alljoistsandbearersformingpartoftheloadingareaare adequatelysecuredinpositiontopreventafall,asdescribedin section4.1.8.3ofthisguide• layingtheformplydeckproceedsasdescribedinsection 4.1.8.3ofthisguide• astartingpointforlayingthedeckisclosetotheformply stack so as to minimise worker exposure to the risks of injury from manually handling the form ply sheets.

4.1.8.2 Typical work system for a leading edge

The following work system may be used to construct the formwork deck for typical multi-level construction. The work system is specificallyintendedforsituationswheretheverticaldistancebelowthedeckbeingconstructedisgreaterthan2m,butwiththeuse of false decks may be used irrespective of the distance to the floorbelow.

1. PlacebearersontheU-headsoftheformworkframesfromthe workingplatformprovidedimmediatelybelow.Securebearers topreventmovement,i.e.bynailingto,orwedgingin,the U-headsbeforejoistsareplacedontop.Noeccentric(un- centred)loadsshouldbeappliedtotheU-headsunless specificallyallowedbytheformworkdesigner.

2. Placejoistsonthebearersinaprogressivemannerfromthe work platform located directly below the area to be worked on,andspacedat450mmcentres(maximum)orsothatthegap betweenjoistsdoesnotexceed400mm.Securethejoists against any movement should a worker fall onto them.

3. Secureanycantileveredbearersandjoiststopreventupliftor dislodgement prior to anyone working on them.

4. Layoutformply,orotherdeckmaterial,progressivelyas describedinsection4.1.8.3.Whereverpossible,thedirectionof theleadingedgeshouldbeperpendiculartothejoists,i.e. paralleltothebearers(referFigure8).

• Formplyshouldbeplacedonthejoistswiththeinstaller located behind the sheet as it is positioned whilst standing on the previously laid sheet or work platform provided. If this is doneconsistently,shouldapersontriporstumbletheywould fall onto the sheet and not from the leading edge.

• Planningshouldtakeintoaccounttheoptimumpositionfor theloadingbay,ordirectionofformplyplacementsothat laying out of the sheets starts at the loading bay where the formplyisinitiallystacked,reducingtheneedformanual handling and carrying sheets.

5. Coverorprotectallpenetrationsleftbehindtheleadingedge. Coversmustbesecurelyfixedandclearlysignedtoindicatethey areprotectingapenetration(seesection4.1.10).

6. Nailorotherwisesecureformplytothejoistsassoonas practicable. • Iftimbershavenotbeenfixed,edgeprotectioncomplying withOHSWRegulations2010(Division13–Preventionof Falls),mustbeerectedleadingawayfromthesidesofthe leading edge. • Onlypersonnelinvolvedintheconstructionoftheformwork maybelocatedintheformworkconstructionzone.Anyone not involved in this process should be excluded. • Theleadingedgemustbefreeofoil,sawdustand obstructions to reduce the likelihood of slips and trips.

4.1.8.3 laying a form ply deck

Aformworkdeckmustbelaidinaprogressivewaythatincludesamethod of preventing falls below the deck. This control measure is particularly important in situations where a false deck has not been providedwithin2mbelowthelevelofthedecktobelaid,andthepotential fall distance is therefore greater than 2 m.

Whereafalsedeckhasnotbeenprovidedwithin2m,formplymayonly be spread on the joists where:

• aminimumoffourjoistsat450mmcentres(400mmgaps, totalling1.8m)arelocatedonbearersnexttotheperson, andthejoistsextendforatleast1.8mallround(seeFigure8). Therefore,intheeventofafall,thepersonwillfallontothejoists and be prevented from falling further• layingtheformplysheetscommencesfromtheperimeter scaffolding or other edge protection that has been provided at theperimeteroftheformwork,e.g.attheloadingbaywherethe form ply is stacked• theformplyislaidinfrontofthebodysothatifthereisa stumble,thefallislikelytobeontopofthesheetsbeinglaid

Fig. 8 – Maximum spacing of timbers around worker where false deck is over 2 metres below Figure 8 – Maximum spacing of timbers around worker

where false deck is over 2 m below

≤400 mm

≥1.8 m

≥1.8 m

16

• joistsarefixedtopreventsidewaysmovement.Insome situations,theremaybeapossibilityofapersonfallingthrough thejoistsifthejoistsspreadastheperson’sbodymakescontact with them during a fall. This is more likely to be a potential hazardwhentheperson’sfallisinthesamedirectionasthe layofthejoists.Fixingjoiststopreventsidewaysmovementwill minimise this possibility.

4.1.8.4 laying a metal deck

Ametaldeckshouldbelaidinaprogressiveway.Whereafalsedeckhas not been provided within 2 m below the level of the deck to be laid,metaldecksmayonlybelaidwheretheuseoffallpreventionsystemshavebeenprovided.Worksystemsfollowingthehierarchyofcontrolsmustbeused.Examplesincludeelevatingworkplatforms,scaffolding,personalfallprotectionsystemsandanti-glaremeasures(refertoFigure9).

4.1.9 cantilever requirements

AS/NZS 4576: 1995 Guidelines for Scaffolding requires that the design of cantilevered scaffolds and the adequacies of their supportingstructuresmustbeverifiedforcompliancewiththerelevant requirements of AS/NZS 1576.1 Scaffolding Part 1: General Requirements byacompetentperson,suchasanengineerwithexperience in structural design.

Cantileveredbearers,joistsandplysheetscanbehazardouswhenleft unsecured. The weight of a person standing on the cantilever maycausetilting,resultinginthepersonormaterialfalling.

Formworksystemdesignersshouldminimisetheuseofcantileverswherepossible.However,insomesituationswherecantilevered

sectionsareunavoidable,theformworkdesignerorengineermust consider the potential for people and stored materials to causecantileverstopivot.Formworkdesignsmustindicatewherecantilevers are to be positively secured so that the weight of a person or material does not cause the section to pivot.

4.1.10 Penetrations

Anypenetrationwherethereisariskthatapersonoranobjectcouldfallthroughmustbecoveredorsecurelyguarded.Openpenetrations,suchasstairwellvoidsorpenetrationstoallowforservices,createhazardsforanyoneonaformworkdeck.Apersonmayfallthroughlargerpenetrations,sustaininjurybysteppingintoasmallerpenetration,oranobjectmayfallthroughtheopeningontoworkersbelow.Allpenetrations must include cast-in metal mesh as a backup system.

Themeshshouldhaveasmallaperture(e.g.50x50mmmeshsizeorsmaller),andbemadeofmaterialcapableofwithstandingthepotentialimposedload.Meshprovidedoverlargepenetrationsmayrequireengineeringcertificationtoensureitcanwithstandpotentialloadsincludingpeople,equipmentandmaterials.

Whereholesarecutinthemeshforservicestopassthrough,theholeshouldbecuttotheprofileoftheservicesothatmeshremainscovering the penetration.

Ungradedplywoodcoversarenotadequatebecause:

• thecovermaybeindistinguishablefromotherpiecesofply• itmaybedifficulttodetermineiftheplywoodisproperlysecured• securedplywoodcoverscanbeunsecuredtogainaccessand subsequently may not be re-secured.

Figure 9 – Safe Work System for laying metal deck(Note:Fallpreventionsystems)

17

Plywoodcoversmustbe:

• structurallygradedandsound• aminimumof17mmthick• paintedabrightcolour• non-slip• markedwiththewords‘DAnger PeneTrATIon beloW‘.

Thecovershouldbefirmlysecuredtotheconcreteanddesignedforpotentialloadsthatmaybeapplied.RefertoFigure10foranacceptablepenetrationprotectiondesign.Beforestrippingformwork,ensure the penetration that will be exposed is securely covered and protected.

Penetrationsarealsohazardousbeforethedeckislaid.Joistsplaced up to the edge of the penetration must be secured so that the timbers cannot spread if a person falls on them.

4.1.11 Working zones for form workers and others

Theformworkconstructionzonemustbesufficientlylargetoensurethat formwork areas are clearly separated from other work areas. A‘formworkconstructiononly’zonemustbemaintainedbehindtheleadingedge.Thiszonemustbeclearlydemarcatedbysignageandameshbarrier.Figure11illustratesthe‘otherwork’zone,theformworkzoneandthearearetainedasedgeprotection(fourjoistsspaced1800mmbeyondthelaiddeck).

       

       

Physical  Barrier  *  

This  distance  may  vary  depending  on  work  requirements  

*Refer to 4.1.6.1 Formwork Construction Zone Physical Barriers

Fig 11. – End view of deck showing working zones

Figure 10 – Example of acceptable penetration protection

*Refer to 4.1.7.1 Formwork construction zone physical barriers

Figure 11 – End view of deck showing working zones

100 mm(min)

100 mm(min)

“DAnger PeneTrATIon

beloW”SLL where required

Zone for oTHer

Workers

formWork consTrucTIon

Zone

This distance may vary depending on work

requirements

Phys

ical

bar

rier *

Dynabolt,orsimilaranchorage

example of sign

Min17mmthick 50mmmeshcastincentrally

FloorslabFloorslab

18

4.1.12 Changingfloorlevels

Formworkdecksmaynotbeflatacrosstheentirefloor,duetodeepbeamsor‘dropdowns’(sometimescalled‘capitals’)aroundcolumns.Suchvariable,unevenfloorsintroducetripandfallhazardsduringformworkerection.Itispreferablethatthesehazardsareeliminatedatthedesignstage(seesection2.1.1‘Buildability’).Fallandtriphazardssuchasthesearemosteffectivelymanagedby ensuring that lower level formwork supports and decks are progressively constructed before work commences on the higher-level areas of the deck.

4.2 formWork erecTIon – moDulAr formWork sysTems

4.2.1 basic modular systems

Thebasicprinciplesdiscussedinsection4.1ofthisguideontraditional systems apply to the erection of modular formwork systems.Althoughtheerectiontechniqueandmemberdimensionsmayvarygreatlybetweentraditionalsystemsandmodularsystems,the principles of maximum potential fall distance and gap width at the working level are applicable:

• thewidthofanygaponaworkinglevelisnottoexceed 400mmunlessafalsedeckhasbeenprovidedwithin2m of the working level• workingplatformsusedformodularsystemsmustalsohave aminimumwidthof450mm.

Bothmodularandtraditionalformworksystemsmustbedesignedto comply with the loadings and general principles of AS 3610: Formwork for Concrete.

Traditional formwork systems are sometimes used adjacent and connectedtomodularsystems,particularlyforunusuallyshapedareas.Wherethisisthecase,theformworkdrawingsshouldshowanyessentialconnectionordesigndetailsandbecertifiedbyanengineerorformworkdesigner.However,componentsfromoneproprietary type of formwork system should not be used as integral parts of other modular formwork systems unless the designer of the modular system states in writing that this is permitted.

Modularformworksystemsareoftenmanufacturedfromaluminiuminsteadofsteelandarethereforelighterinweight.Beinglightweight,theyrequirelessphysicalefforttoerectthantraditionalsystems,andalsotheneedforrepetitivehammeringmaybeeliminated,reducingworkers’exposuretotheriskofinjuryfrommanualtasks.

Becausemodularsystemsarelighterinweighttheymaybemoresusceptible to overturning during erection when exposed to eccentric loading factors such as wind loading etc. This is generally an issue only prior to placement of the decking on the modular support system.Toeffectivelycontrolanyinstability,modularformworksystems must be progressively braced during erection in accordance withthemanufacturer’sinstructions.

4.2.2 Training

Workersinvolvedintheerectionofmodularformworksystemsmustbe trained in the safe erection and dismantling of the system and the inspectioncriteriaforcomponents,particularlyfordefectsthatwouldpreclude their use.

The modular system supplier or designer should provide written instructions for the erection and dismantling of the system. Instructions should include safety instructions equivalent to those detailed in this guide.

Trainingbythemodularformworksystemsupplierisencouraged.FortrainingrequirementsrefertoAppendix2.

4.3 sTrIPPIng formWork

Strippingformworkcanbeoneofthemosthazardousphasesofconcrete construction.

Whilefallingobjectsaretheprimaryhazard,theremayalsobefallhazardsasaresultoffloor,scaffoldorformworkcollapse,aswellasmanualtaskhazardsfromapersonworkinginawkwardpostures,repetitivehandlingofmaterials,orlimitedtaskvariety.

Workersmustbeinformedoftherisksandbeadequatelytrained,sothatstrippingoperationsarecarriedoutinanorderly,progressivemanner,asoccurswithformworkerection.

4.3.1 general formwork stripping

To reduce the risk of injury when stripping formwork/false work:

• installfully-deckedworkplatformsataheightnogreater than 2 m from ground level or the catch deck• erectacatchdecknomorethan2mbelowtheworkarea• suitablybarricadeandsignpostthestrippingarea (withbarriermeshasaminimum).

4.3.2 safe work method statements

Onlyanexperiencedandcompetentpersonshouldpreparesafeworkmethodstatementsforthestrippingoperation.Properlyprepared statements are very useful as a training tool for those who will be involved in this high risk activity. The safe work method statement should detail factors such as:

• thehazardsrelatedtothestrippingprocessandanyequipment and strategies to eliminate or minimise the risks• thenumberofpeopleinthestrippingcrew• thesequenceofstrippingactivitiese.g.detailinghowtheframes and/orothersupportsaretoberemovedandhowfarU-heads may be lowered• whetherthesupportsystemmaybecompletelyremovedina zonepriortoremovaloftheformworkdeck,orwhetherthe supports are to be lowered slightly but still remain under the form ply while it is being removed

19

• whenback-proppingisrequiredoronlypartofthesupport systemistoberemoved,howthestructuralmembersareto remain in place and/or the type and layout of members that will replace the formwork system• anyotherspecialrequirementsinvolvedinthestrippingand or building processes e.g. checking of back-propping after post-tensioning.

4.3.3 Certificationpriortostripping

Priortocommencementofthestrippingoperation,anengineermustprovidewrittencertificationthatformworkcanberemoved.Thiscertificationshouldbebasedonanengineer’sspecificationsforthebuilding,thestrengthoftheconcretemixandthetimeperiodthathas elapsed since the pour.

Anengineermayalsoberequiredtohaveinputintothestrippingsafe work method statement to ensure the concrete element doesnotfail,andmustprovidesufficientdetailonthestructuralengineeringdrawingsasrequiredbysection17‘Formwork’of AS 3600 – Concrete Structures.

Documentation from the concrete supplier verifying the concrete specificationshouldbeavailableonrequest.Aconcretesamplingand testing procedure should be in place to verify that concrete meetsitsdesignspecificationforstrippingpurposes.Guidanceon sampling and testing systems for concrete is provided in AS 1379:2007 Specification and Supply of Concrete.

4.3.4 exclusion zone

Onlythoseinvolvedinthestrippingoperationarepermittedinanareatobestripped.Strippingareasmustbecordonedoffandsigns displayed to keep non-essential personnel out of the area e.g. ‘DAnger – formWork sTrIPPIng In Progress – AuTHorIseD Persons only’.

Itispreferabletorestrictaccesstothewholefloorwheresoffitstrippingistakingplace.Thiswouldnotonlybesafer,butalsoreduces the quantity of signage and barricades required.

Whereothertradesorsub-contractorsarerequiredtoworkonthesamefloorduringthestrippingofwalls,columnsorsmallsectionsofsoffit,theprincipalcontractororemployermustensurethatcontrolsare applied to prevent non-essential personnel from entering the stripping area.

4.3.5 Drop stripping

Drop stripping is an unsafe method of work and cannot be supported by this guidance document. In cases where drop stripping is being considered,theformworkandsupportdesign,andtheconcreteelementdesign,shouldbereviewedbythedesignerandmodifiedtoeliminate drop stripping.

4.3.6 bond reduction

Strippingofformworkmaybeaidedbyreducingthebondbetweentheformmaterialandtheconcrete.Bondstrengthisdependentonthematerialcharacteristics,thesmoothnessoftheformmaterialand age of the concrete. The use of a liquid bond breaker on wall and column forms is one way of reducing the strength of the bond. However,theuseofbondbreakeronfloorformsisnotencouragedbecauseofthesliphazardthatmayresult.

4.4 crAne AnD oTHer loAD HAnDlIng sysTems

4.4.1 loading materials during formwork construction

Formworkstructuresarenotnecessarilysafetoacceptanyexcessloadinguntiltheyarefully-secured.Thatis,untilafterthedeckisinplacewithtie-insandproppingcomplete,andanyproposedloadingareacertified.

Inpractice,someloadingoccursbeforeadeckiscompletede.g. unloading pallets of ply and joists on a partially constructed formworkstructure,tocontinuethedeck.Thisisanunacceptableand dangerous practice which could lead to a full structural collapse ofthedeck,possiblyresultinginseriousorfatalinjury.Toensuretheintegralsafetyofthedeck,materialsmayonlybestoredwhereandwhenthedeckiscertifiedasabletobeartheload.

Formworkersandcranecrewsmustbemadeawareofthespecificlocationsandloadsforcertifiedloadingareas,andthatstackedmaterialsmaycreatepointloadings,whichaformworkstructuremaynot be designed to bear at that point.

Tominimisetheriskofcollapseandotherhazards:

• loadsmustnotbeplacedontheformworkdeckifthe formwork documentation prohibits loading• formworkdrawingsmustclearlyidentifythelocationsand SLLformaximum(pre-pour)pointloadingsforthedeck.These locationsmustbespecifiedbyaformworkdesignerorengineer• cranecrewsmaynotliftmaterialsontothedeckuntilthereisa designatedliftingzone• cranecrewsmustbenotifiedwhenanareaofdeckisreadyto takeaload,andspecifiedloadsmayonlybeplacedinthearea/s designated and placed so that they cannot fall• deliveryofmaterialstothesiteshouldbeplannedsothatloads are not lifted onto unsecured decks• priortoworkersleavingthesite,materialsandequipmentshould be secured to prevent them being moved by wind.

4.4.2 slinging loads

Slingingandun-slingingloadsatheightisalwaysahighriskactivity.Safeworkmethodsandfallpreventionsystemsareessentialforthisactivity(refertosection4.1.8.1)

Adogman,orotherpersonengagedinslingingloads,mustbeprovided with adequate fall protection and a safe means of access

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when working at 2 m or more above the deck.

The use of fall arrest systems for workers slinging formwork loadsisusuallyimpracticalandisnotrecommended.However,itmaybereasonablypracticabletofitplatformsandedgeprotectionas fall protection.

4.4.3 lifting gear

Guidanceontheuseandinspectionofchains,wireropesandsynthetic slings is provided in the following publications:

• AS 2759: 2004 Steel wire rope – Use, operation and maintenance• AS 3775.2: 2004 Chain slings – Grade T Part 2: Care and use• AS 1353.2: 1997 Flat synthetic webbing slings Part 2: Care and use.

Basicitemsthatneedtobecheckedinclude:

• liftinggearistaggedandallrelevantinformationlisted (e.g.relevantinformationforachainslingisgradeofchain, safeworkingload,manufacturer,chainsizeandAustralian Standardmarking)• liftinghookshaveoperablesafetylatches• liftingeyesandinsertsarecompatible• liftingslingsareserviceableandnotdamaged(i.e.haveno excessivewear,damagedstrands,cracks,deformationand/or severecorrosion)• syntheticfibreslingsaremaintainedingoodcondition,arerated fortheloadbeinglifted,haveasuitableslingingconfiguration and are protected from sharp edges.

Itismostimportantthatallliftinggearincludingslings,hooks,wireropes,pendantsandmaterialboxesareperiodicallyinspectedfordamage and wear. The period between inspections may depend on the severity of use with the exception of:

• chainslings,whereinspectionsmustnotexceed12months• syntheticfibreslings,whereinspectionfordamagemustbe undertaken before each use and full inspection at least every threemonths.Refertosection9ofAS 1353 .2: 1997 Flat synthetic webbing slings, part2:‘Careanduseforinspection items’andsection11for‘DiscardCriteria’.

Documented maintenance records for the lifting gear should be available for inspection on-site.

4.4.4 lifting formwork materials

• Crane-liftedloadsmustbeslungandsecuredsothattheload (oranypartofit)cannotfall.• Weightsofwall,liftorcolumnformsshouldbeprovidedon-site with formwork documentation and made available for inspection by all interested parties.• SLLsmustbeclearlymarkedonbins.

• Liftingboxesintendedforliftingpeoplemustbedesign registeredwithSafeWorkSAandsuitablyconstructedforother material being lifted.• Fourchains(oneineachcorner)mustbefittedtoliftboxesto maintain stability.• Liftingboxesmustbeinspected,maintained,andinspection records kept.• Specifically-designedliftingboxesshouldbeusedtoliftsmaller components(e.g.spigots,U-heads,baseplatesandcouplers). Boxesmusthaveenclosedsidesorrobustmesh(withopenings lessthantheminimumsizeofmaterialsbeinglifted).• Loadscontainedwithinliftingboxesshouldbesecured against movement.• Materialsmustnotbestackedhigherthanthesideofthebox unless they are adequately secured.• Formworksupportframesmusteitherbetiedtogetheror secured with lifting slings wrapped around the load. • Loadsofjoistsorbearersshouldbestrappedtogether before lifting.• Taglinesmustbeusedtocontrolloadsandforms,andmust befixedtotheload,nottheliftinggear.• Formplyloadsshouldbestrappedtogetherandliftedina flatposition.• Ensure,wherepossible,thatallloadsaresupportedondunnage and the load is uniformly distributed over the supporting surface.

Priortoliftinganyitems:

• removeanywasteconcreteetc.fromformsoranyother materials or equipment to be lifted to ensure the waste does not fall onto people below• inspectallloadscloselytoensureallloosematerialsandtools have been removed.

4.4.5 lifting lugs

Chainslingsattachedtolugsorholescutintopartofaloadareoftenusedtoliftbins,wall,liftwellorcolumnforms(insteadofwrappingtheliftingslingsaroundtheload).Informationverifyingthestructuraladequacy of the lifting points must be available.

Anengineermustverify:• thestructuraladequacyoftheliftinglug• themeansofattachmenttotheload(usuallyweldedorbolted).

4.5 use of lADDers

Laddersmustbesecuredatthetoporbase,orwhenthisisimpractical,heldfirmlyatthebasebyanotherperson.Wherepracticable,alternativestoladderssuchasworkplatformsorstairaccesssystemsmustbeused.Fixedorpermanentladdersmustcomply with AS 1657 – Fixed platforms, walkways, stairways and ladders – Design, construction and installation.

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Whereladdersareprovidedasaccesstoalivedeck:

• theymustextendatleastonemetreabovetheaccessed surface,besecuredagainstmovementandbesetuponafirm, level surface• theymustbeofindustrialstandardwithaloadratingofat least 120 kg• singleandextensionladdersmustbeplacedatanangleof between70degreesand80degreestothehorizontal (‘4up,1out’rule),exceptinsomeraresituationswherethis is impractical• singleladdersmustnotexceed6.1minlengthandextension laddersmustnotexceed7.5m.

Otherissuesregardingthesafeuseofladdersinclude:

• metalormetalreinforcedladdersmustnotbeusedinthevicinity ofliveelectricalequipment.TheOfficeoftheTechnicalRegulator (OTR)providesinformationoncompliancewithsafeworking distances in the vicinity of live electrical wires• nevertouchaladderthatisincontactwithelectricalpowerlines• aperson’sfeetmustalwaysbemorethan1mfromthetopof the ladder• laddersarenottobeusedonscaffoldingorelevatedwork platforms to gain extra height• laddersmustnotbepositionedaboveoradjacenttoopeningsor edgeswhereapotentialfallcouldoccur.Aworkplatformwith edge protection should be used instead• laddersshouldnotbeusedinaccesswaysorwherethereis pedestrian,vehicularormobileplanttrafficunlessarisk assessment has been undertaken and other precautions have been considered• alwaysmaintainthreepointsofcontactwhenusingladders.

5. special requirements for wall and column forms5.1 brAcIng for WInD loADIng

Wallandcolumnformsmustbedesignedtowithstandallliveanddeadloads,includingwindloadpriorto,during,andaftertheconcrete pour. The bracing and forms must not be removed from thecastelementuntilitissufficientlymaturetosafelywithstandpotential impact loads and wind loads.

Priortostripping,anengineerorothercompetentpersonmustprovidewrittencertificationthattheformworkcanberemoved.

Bracingmustbedesignedtosuititsapplicationandverifiedbythedesigner(refertosection2.2.1).Bracingelementsmustbedesignedand installed to resist both positive and negative wind generated loads.Bracinganchorsshouldpreferablybecast-intypeor‘through-bolts’thatextendthroughbothsidesoftheanchoringmedium.Drill-inanchorsofthefollowingtypemaybeused,providedtheyareinstalledinaccordancewiththemanufacturer’sinstructions:

• undercuttypeanchorthatdoesnotrelyonfrictiontofunction• expansionanchorsofthehigh-loadslip,torquecontrolledtype• coilbolts.Thecorrectoperationofcoilboltsisgreatlydependent on whether they are installed in accordance with a manufacturer’sspecifications(e.g.drillingthecorrectsizedhole andapplyingthecorrecttorqueinconcreteofadequatestrength).

Drill-intypeanchorsmayhaveaspecificinstallationtorquesetrequirement to function correctly. Torque measurements should be madeusinganaccuratelyadjustabletorquewrench.Analternativemethod that may be used to verify the torque could be a calibrated ‘rattlegun’.Recordsverifyingthesettingtorqueforalldrill-intypeanchorsshouldbeavailableon-site.Manufacturersnormallyspecifythe minimum distance from a concrete edge that an expansion anchor may be installed.

5.2 Access PlATforms

Mobilescaffolding,purposebuiltworkplatformsorelevatingworkplatforms may be suitable in providing the essential safe access to elevatedworkareasfordogmen,steelfixersandconcreters.Edgeprotection must be provided on any access platform.

Platformsmustbedesignedtoprovidesufficientaccessandworkingspaceforthenumberofpersonnelrequiredforspecifictasks,andmust be positioned at a height and distance from the form so as to minimisereachingandstretchingmovementsandlimitaperson’snecessary exertion.

Concretepouringsystemsmustprovideadequatesafeworkingspace,withedgeprotectionprovided,forallworkers.

Castorsonmobileworkplatformsmustbelockedatalltimesexceptwhen they are being moved.

Allplatformsmustbedesignedforstabilityandresistancetoanysideloadingthatmaybeappliedduringaconcretepour.Lightweightaluminium scaffolding may not have adequate stability when subjected to side loading and may require additional bracing.

5.3 lIfTIng meTHoDs

Wallandcolumnformsmayonlybeliftedwithapositiveliftingsystem,suchasliftinglugsorbywrappingliftingslingsaroundtheformsuchthattheformcannotslipoutoftheslings.Purposedesignedliftinglugsmustbeusedwhereverpracticable(refertosection4.4.5).

Anengineermustprovidedocumenteddesignsforwallandcolumnformliftingpoints,andthedesigndocumentationshouldbeavailableon-site.Whereliftinglugsareattachedtotheform,anengineermustspecifythefixingorwelddesign,andthemanufacturermustensureand certify that the attachment or weld complies with the design requirements.

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Formingliftingpointsbycuttingholeswithoxy-acetylenetorchesisunacceptable and must not be used as:

• theloadcarryingcapacitycannotbeguaranteed• itmaydifficulttoattachliftinggear• positioningoftheholemaybeinaccurate• theformmaybedamaged.

6. special requirements for slip forms and jump formsThissectionappliestoslipforms,jumpformsandcrane-liftedformsthat incorporate working platforms and enclosed cells in which people are required to work.

Slipformsandjumpformsaretermsgiventoself-climbingformworksystemsspecificallyintendedtoconstructconcreteservicecores,walls and columns in high rise buildings and other concrete structuressuchassilosandchimneys.Inslipforms,theclimbingis usually carried out continuously during the concrete pour which maybecompletedtofullheightinonepouringoperation.Withjumpforms,theclimbingisdoneinsteps,liftingthecompleteformunittothenextlevelfollowingeachconcretepour.Theterm‘climbingform’isalsousedtodescribeeitheraslipformorjumpform.Climbingoperations are usually powered by hydraulic rams or electric motors connected to climbing feet or screw shafts.

Slipformsandjumpformsusuallyconsistofanumberofdecksandmayalsobefittedwithtrailingscreensthataresuspendedfromtheform.Aswithperimeterscreens,trailingscreensmay:

• provideedgeprotection• preventmaterialsfromfalling• providesupportforworkplatforms,oracombinationof these uses.

Notwoslipformsorjumpformswillnecessarilybeidentical,astheirdesignwillbebasedonthesizeandconfigurationofthestructureorbuilding under construction.

The work systems and layout of some crane-lifted forms may also be similar to those associated with slip forms and jump forms. This may be the case for crane-lifted forms provided for the inside of lift shafts.Whilemostoftheinformationinthissectionappliestoslipformsandjumpforms,someoftheprinciplesmayalsoapplytocrane-lifted forms.

Whendesigningandoperatingthesetypesofformsystems,thefollowing issues must be addressed:

• providesafeaccesstoallareasandworkplatforms• controlrisksassociatedwithworkingatheight• developsafeworkmethodstatementsandusingthemtotrain workers in the safe operation of slip and climb form systems• providesufficientworkingspaceandheadroom

• specifyandprovidesafeworkmethodstatementsformanual handlingofshuttersandothercomponents,e.g.theuseof cranes to lift shutters and provision of safe access for workers attaching slings to shutters• ensureadequateventilationandlightinginallworkareas• provideadequateamenitiesforworkersgiventhatslipform operations often continue for extended shifts• alwaysuseHotWorkPermitsforslipformandjumpformsystems• ensuresufficientfireextinguishersareprovided• ensureemergencyprocedures,includingfortheretrievalofan injured or incapacitated person from any work area located withinthestructurearedeveloped,implementedandtrialled.

It is acknowledged that it may not be practicable to provide an access system and working environment on a jump form or slip formthatisofthesamestandardaselsewhere.However,anyoneincontrolofaproject,taskorworkersmustcomplywiththeirobligationsundertheOHSWAct.

6.1 Access AnD egress

Accesstoslipformandjumpformsystemsmaybeprovidedinavariety of ways including one or more of the following:

• personnelandmaterialhoistsonthebuilding• permanentstairsystemsinthebuilding• atrailingstairsystemsuspendedfromtheslipformorjumpform• atrailingladdersystem.

Atrailingstairsystemispreferabletoaladdersystemasitiseasiertoascendanddescend,andemergencyevacuationisgenerallysaferand easier on a stair system. The access area between the trailing accesssystemandthebuildingmustbeclearoftriphazardsandthereshouldbenogapsexceeding50mmwidebetweenplatforms.

The formwork designer must ensure that a trailing access system is designed for additional loads that could be applied in an emergency evacuation situation. The design must ensure that not only the strengthoftheformsystemitselfisadequate,butalsotheformworkstructure safely supports any applied loads from the access system.

Atrailingstairaccesssystemshouldbedesignedforaloadofatleast2.5kPaunlessthedesignerspecifiesotherwise.Wherethedesignerspecifiesalesserliveloadthan2.5kPa,thefollowingapplies:

• asignstatingthemaximumloadlimitmustbefixedtothe stairs in a visible position• writtenproceduresmustbeimplementedtoensurethetotalload limit is not exceeded.

Laddersmustbesecuredinplaceandbeplacedatananglebetween70and80degreestothehorizontal,wherethisispractical.

Accessopeningsforladdersonworkingdecksshouldbeprovidedwithtrapdoorsthatareclosedwhennotinuse,easilyopenedfromabove,anddonotcreateatriphazardonthedeck.

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Accesswaysshouldbekeptfreeofmaterialsandrubbishtopreventobjects falling to the level/s below.

6.2 Work PlATforms

Division13–PreventionoffallsoftheOHSWRegulationsspecifiesrequirements for work platforms. These requirements also apply to slipformsandjumpforms.However,thefollowingpointshighlightspecificissuesthatmayapply:

• Whenplacingsteelorpouringconcreteintoaform,controls must be implemented that prevent a person falling into or from the form. The risk of this is higher when the form is greater than225mmwidepriortoplacementofreinforcingsteel. Workersmustalsobeprotectedfromtheriskofbeingimpaled onprojectingreinforcingbarsorotherobjects.Suitablecontrols may include edge protection on the internal side of the working platform,orreinforcementmeshtemporarilyplacedontopof theform,enablingthesteeltobefedthroughthemesh(see Figure12).

• Thedesignandconstructionofplatformsmustincludepositive fixedsecuritysothatjammingormovementcannotoccurunder eccentric loads e.g. where work platforms have a trailing screen ononesideandaresupportedbyabuildingparapetontheother, uplift may occur from wind loading or where a platform is not levelandisunsecured.Ifthisoccurs,theplatformmayjamor otherwisemoveundertheunbalancedload,causingaperson to fall.• Whereindividualcellsofaformareclimbedatdifferenttimes, edge protection must be provided separately on each cell.• Safeworkmethodstatements,developedforallhigherrisk aspectsofslipformorjumpformsystemsandaccesssystems, will assist in ensuring safe systems are implemented and provide a sound training aid for workers engaged in this activity.

6.3 TrAIlIng screens AnD PlATforms

Trailing screens can provide edge protection and a means of preventing falling objects. They can also be designed to support lower,suspendedworkingplatformsforrepairingorpatchingconcrete,andtoprovideaccessforanyoneclimbingtheform.Theformworkdesignerwillneedtospecificallyaddressanddocumentallissues for which the trailing screen system is designed. The design must address the following:

• Theremustbeasuitabledesignloadingforanyplatformson thetrailingsystem.Asaguide,platformsmustbedesignedto supportaminimumloadof2.5kPa.Adesignermayreduce this if the number of people is strictly limited and controls are implementedon-sitetoensurethespecifiedloadisnot exceeded.Ifthedesignloadislessthan2.5kPa,thismustbe statedindocumentationkepton-siteandsignsmustbefixedto the platforms stating the maximum load permitted in kilograms. Sitepersonnelmustbemadeawareofandcomplywiththe maximum loading that applies to the trailing platform. • Strategiesmustbeimplementedtoadequatelycontrolthe riskfromfallingmaterials(seesection5forfurtherguidance).• Allplatformsmustbesecuredtopreventupliftoranyother unplanned movement.• Ariskassessmentofaformsystemmustincludetheneedfor, anduseof,laddersandedgeprotection.Thesystemmustmeet therequirementsoftheOHSWRegulations.• Apersonmustnotrideontrailingplatformswhiletheplatforms are being crane-lifted. If access or work is required whilst a cranesupportsthetrailingplatform,anotherworksystemmust be devised. This could involve another crane with a registered workbox,oraseparateaccessscaffoldsystem.• AnyworksystemchosenmustcomplywiththeOHSW Regulationsandincludesafeworkmethodstatementsbasedon riskassessment,withriskcontrolstrategiesbasedonapplication of the hierarchy of control.

6.4 clImbIng THe form

Climbingisusuallycarriedoutusingaseriesofclimbingdevicesset up to lift at the same time and at the same rate. If the lifting system is not properly synchronised the form may become wedged onthestructure,orstructuralmembersmaybeoverloadedandbecome unstable.

There should be a systematic approach to ensure that the form remains within level tolerances during the climbing process. The system may be automated or may rely on operators stopping each individualdevicecontrollingtheclimbingprocess.Whicheverprocessisused,thefollowingmustbeobserved:

• Asafeworkmethodstatementmustbedevelopedtotrain personnel and manage the climbing process.

Figure 12 – Mesh used as fall protection on wall pour

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• Onlythoseworkersdirectlyinvolvedwiththeclimbingprocess may be on the form during the climb.• Anypotentialniporshearpointswhereapersoncouldbeinjured duringtheclimbmustbeidentifiedandcontrolled.• Allobstructionsandlooseitemsontheformaretoberemoved priortoclimbing.Aninspectionchecklistand‘sign-off’procedure for this should be implemented. Items typically left on forms includeZ-bars,ferrulebolts,insertanchors,coversand hand tools.• Itisimportanttoensurethedifferentpartsoftheformremain level during the climbing process.• Electricalcables,waterandotherpipedservicesshouldbe designed and installed so that they will not catch or rupture as the form is climbed.

Formsmustbeeffectivelysupportedatalltimesduringclimbingoperations,particularlywhenremovingaformfromaverticalelement.Seriousincidentshaveoccurredwhenithasbeenassumedthataformissupportedfromacrane,whenitisonlyrelyingon‘throughbolts’forsupport.

Inoneincident,whentheboltswereremoved,theform-to-concreteadhesive forces failed a short time later. The form fell while workers were still standing on a platform attached to it.

Thishazardappliestobothcrane-liftedformsandjumpforms,whichmustalwayshaveapositivemeansofsupport.Workersmustnever be in a position where they rely on formwork adhering to the concrete surface for support.

6.5 TrAInIng

Slipformandjumpformoperationsrequirespecialisedworksystemsandpresentuniquehazardstoworkers,requiringspecifictrainingand specialised safe work method statements for personnel working on the forms.

Trainingandthedevelopmentofsafeworkmethodstatements,shouldinclude,butnotbelimitedto:

• themaximumloadingsthatcanbeappliedtothevariousareas on the form. This would include information about areas where materials can be stored• restrictedaccessareasandproceduresfortheinstallationand removal of edge protection• sliporjumpingproceduresforthoseinvolvedintheseoperations• requirementsfortheapplicationofHotWorkpermits• emergencyevacuationproceduresforthoserequiredtoworkon the form• firefightingprocedurestobeusedinemergencysituationsprior tofirefightingpersonnelarrivingatthescene• anyotherspecialworkproceduresthatspecificallyapplyto workingontheform,e.g.timelimits(wheretheseapply)for working in cells or safe undertaking of manual tasks

• communicationandremoteworksystems–nopersonistowork aloneand‘buddy’systemsaretobeencouraged.

RefertoAppendix2forothertrainingindifferentareas.

6.6 HeAlTH Issues AnD AmenITIes

Safeaccessandadequateventilationtoallcellsmustbeprovidedinclimbingformsystems.Extendedperiodsinhotandcrampedworkingconditionscreateadifficultworkingenvironmentandtheseissues should be considered during planning and job design. It may be necessary to specify job rotations or maximum times spent in cells,dependingontemperature,humidity,cellsizeandtheparticularactivities being undertaken. Time limits and job rotation should be considered in consultation with workers when developing safe work method statements.

Duetothenatureoftheworkandtheworkenvironment,theprovisionofadditionaldrinkingwatersupplies,toiletsandamenitiesmay also be required.

6.7 engIneerIng Issues

The design of climbing form systems is more complex than formwork systemsforfloorsandincludestheconsiderationofwindloadingandotherstressesgeneratedduringclimbing.Suchformworksystemsrequiregreatertechnicalandengineeringinput,andmustbeclassifiedasnon-basic,withanengineerasthedesigner.

The climbing form designer must be involved in both the design of theformandindevelopingsafeworkmethodstatements,sothatanyongoing design issues occurring during form erection over the life of the building project are addressed.

Somedesignproblemsassociatedwithclimbingformsystemsmaynot become apparent until the job is in progress and system design changes may be necessary. Designers and principal contractors must implement consultative arrangements that include regular inspectionsoftheworksduringaclimb,andconsultationwiththoseinvolvedintheoperationtoidentifyanydifficultiesorsafetyissues.

Section2ofthisdocumentdiscussesengineeringissuesassociatedwithformworkingeneral.Inadditiontothoseissues,thedesignermust address the following factors for climbing systems:

• minimumconcretestrengthrequiredpriortoclimbing• allowanceforallloads,includingallliveanddeadloadsthatmay be applied to the form system such as: − loadscreatedbyworkers,impactloadsfrommaterialslifted onto the form and concrete-placing activities − the effects of additional and eccentric loading during climbing• themaximumallowableskewduringaclimb,andany procedurestoeitherminimisethepossibilityofthisoccurring,or rectify a situation if forms do become skewed

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• anyeffectrescueproceduresmayhaveonthedesignor operationoftheform.Rescueproceduresmayrequireaccess toalllevelsoftheformandcells,eitherthroughtheprovisionof gates or by removal of panels on the form.

Anyspecificriskcontrolrequirementsmustbedocumentedinthesafe work method statements.

6.8 emergency Issues

Fireextinguishers,hosesandothermeansoffirepreventionandcontrol must be provided on climbing forms in accordance with relevantlegislation.Emergencyproceduresmustbedeveloped,documented and implemented and all personnel must receive trainingontheprocedures.Alistofthosewhohavereceivedtrainingmustbedocumentedandkept(referFigure13).

The emergency procedures must include as a minimum:• methodsforalertingworkersintheeventofanemergency• methodsandtimingforevacuatingworkersfromeachlocation or cell • rescueproceduresintheeventofseveremedicalconditions• whoisresponsibleforensuringevacuationtakesplace• personnelintheemergencyresponseteam• trainingrequirementsforanyoneinvolvedinrescuingothers, where outside experts cannot be responsible for performing the rescue• trainingintheuseoffireextinguishers• evacuationmusterpointsbothonandofftheform.

Inremoteareas,amorethoroughriskassessmentmustbecarriedout for emergency rescue.

Whereaformcanbeaccessedusingcraneson-site,adesign-registeredfirstaidboxforemergencyrescueofaninjuredandincapacitated person/s must be readily available and accessible at all times while work is being undertaken.

Bothdesignersandthoseincontrolofasiteortaskmustconsiderthe effect the formwork design may have during an emergency response,aswellastheirongoingresponsibilityduringconstruction.

Safelyremovinganimmobilisedorunconsciouspersonduringanemergency evacuation of a formwork cell needs to be considered and planned for. This may include creating emergency access holes anddoorwaysthroughdecksandscreens.Proceduresmustidentifyhowtoaccesslift-voidsandotherareas,includingcellswithinthecore,whichmayhavelimitedaccess.

Emergencyservicescontactsmustbeclearlyidentifiedandbeprominentlydisplayedon-site.Allpartieson-site,includingtheprincipalcontractor,sub-contractorsandworkers,mustagreeonthenominated emergency service contacts.

Figure 13 – First aid, fire control and emergency retrieval equipment on-site

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7. falling objects7.1 HAZArD conTrols

Hazardsfromfallingobjectsaresignificantandcanbepresentwheneverworkersandothersareerecting,alteringorstrippingformwork,whenslippingandjumpingformworkoperationsareoccurring,andalsowheneverloadsareliftedoverworkareas.

Anyoneincontrolofaworksite,workareaortaskhasanobligationto control any risks from falling objects where workers or any other person could be injured by a falling object during formwork activities.

Evensmallobjects,suchasboltsorconcreteaggregate,fallingfromheightcancauseseriousinjury.Controlmeasuresmustaimtopreventobjectsfromfallingor,ifthisisnotreasonablypracticable,prevent injury if an object has fallen.

Inparticular,whenerectingordismantlingformwork:

• close-offadjoiningareastonon-essentialpersonneltoprevent objects falling on or hitting people• erectperimetercontainmentscreensforeachpartofthebuilding from where objects could fall• ensurecontrolmeasuresareinplacetopreventscreen componentsfromfallingduringerection,extensionorreduction of perimeter containment screening.

7.2 PrevenT THe objecT from fAllIng

Controlsmustbeappliedatthesourcetopreventobjectsfromfalling;thatis,eliminatetherisk.Thisisthemosteffectivecontroltoprevent injury or death caused by falling objects.

Good housekeeping practices are the most effective way of preventingsmallobjectsfromfalling.Ensureitemsarecleanedupandkeptawayfromedges,voidsandpenetrations.

The recommended control measure to prevent objects from falling outside the structure is the use of perimeter containment screens. The screens are effective as a control measure from falling objects for the protection of the public in adjoining areas as well as for safety and protection on-site.

7.3 PerImeTer conTAInmenT screens

Perimetercontainmentscreensareprotectivestructuresfixedtotheperimeterofabuilding,structureorworkingplatform.Theiressential purpose is to prevent objects and people from falling outsidetheworkarea,significantlyreducingtheriskofinjurytoworkers and the public.

Screensshouldbeusedduringthefullconstructionprocess,especially during formwork erection or stripping. They are usually sheeted with:

• timber• plywood• metalorsyntheticmesh.

Containmentscreensmaybesupportedbythebuildingorstructure,orbyspecificallydesignedscaffolding.Thescreenscanalsoactasperimeter fall protection on a top working platform. To fully comply withtheserequirements,thescreensmustextendatleast2mabovethe working surface.

Whenformworkisbeingerectedordismantledimmediatelyadjacenttoscreens,theymustextendaminimumof2mabovetheworkingdeck/stripping area to provide a higher level of protection for the public and for those workers outside the building area.

Whenselectingcontainmentscreens,considerationmustbegiven to its:

• abilitytosupportorcontainimposedimpactloads,including buildingmaterials,equipmentandwastematerials• resistancetowindloadsonthesupportingstructure• requiredfrequencyofinspection• chemicalreactivity,includingflammability• ventilationrequirements(refertoAS 1668.2: 2002 The use of ventilation and airconditioning in buildings – Ventilation design for indoor air contaminant control forguidance)• lighttransmissionrequirements(refertoAS 1680:1976 Code of practice for interior lighting and the visual environment forguidance)• degreeofprotectionprovidedfromrainorwashing down operations• patternandfrequencyoffixingpoints• gapscreatedbyafixingmethod.

Containmentscreensmustremaininpositiontopreventanyobjectfallingforthefulldurationofformworkoperations–fromcommencingformworkerectionuntilsoffitstrippingiscompleteandallmaterialsareremovedfrom,orstackedon,thefloor.

7.3.1 screen height at building step-ins

Asstatedabove,perimetercontainmentscreensmustextendabovethe formwork erection area so that materials cannot fall to the ground,orontootherworkortrafficareas.

Wherethehorizontalsurfaceunderconstructionstepsinfromtheoverallbuildingperimeter,e.g.foraplantroomonabuildingroof,the perimeter screens must be erected to a height that will prevent any materials falling to the ground from the top of the stepped-in structure.

OneexampleofanacceptablemethodtopreventfallingobjectsreachingthegroundisillustratedinFigure14.Inthisexample,theoutsideedgeofthesteppedinstructureis‘W’metresfromtheperimetercontainmentscreenandtheliftheightis‘H’metres.

Topreventanobjectfallingfromthetopofthestepped-instructure,orbeingejectedfromthetoplevel,andfallingtothegroundoutsidethebuildingperimeter,theheightofthescreenshouldbesuchthatthe angle of an imaginary line from the top of the screen to the top

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oftheformworkplatformrailisamaximumof45degreestothehorizontal,withaminimumacceptablescreenheightof2m.

The calculation for the required screen height is:

screen Height (metres) = (H + 0.95) metres – W metres(with a minimum acceptable height of 2 m)

Non-essentialpersonnelmustnotenterthe‘No-Go’areanexttothestep-in unless positive controls are in place to prevent anyone being struck by falling objects e.g. catch platforms or further screening.

7.3.2 Perimeter screen gaps

Topreventmaterialfromfallingbelow,gapsbetweenperimeterscreensandtheformworkdeckorfloormustnotexceed25mm.This can be achieved by:

• installingpermanentlyfixedplycovers• installingcatchplatforms–removableshieldsthatare connectedtoscreens,withprocedurestoensuretheadjacent area is cleaned up before the shields are removed.

Coversmustbedesignedforpotentialloadings,suchasloadsapplied by workers and the impact loadings of falling materials. TheymustalsobemarkedwithaSLLiftheycanbeaccessedasa platform.

Catchplatformsdeflectfallingobjectsbackintothebuilding,preventingthemfromfallingfurtherdownthegap.Catchplatformsmust be attached to screens by a system that ensures that they do not dislodge and fall when the screens are lifted. The system must be sufficientlyrobusttowithstandanyworkplaceenvironmentimpacts.

Catchplatformsmustbedesignedbyanengineertoresistimpactloadslikelytobeapplied(i.e.frombearers,formply,propsetc).Wherechainisusedtosecurecatchplatforms,itmustmeettherequirementsofAustralianStandardswithaknownloadlimit.

8. Health concerns8.1 noIse

Division10–NoiseoftheOHSWRegulationsdescribeswhatmustbe done to prevent risks from exposure to excessive noise at work. TheApprovedCodesofPracticeundertheOHSWActare:

• National Code of Practice for Noise Management and Protection of Hearing at Work [NOHSC: 2009 (2004)],3rdEdition(available fromtheSafeWorkSAwebsiteatwww.safework.sa.gov.au)• AS 1270: 1988 Acoustics – Hearing Protectors.

TheCodesrequireallworkerstobeprotectedfromtheriskofnoiseinducedhearingloss(NIHL)duringtheirwork.Ifnoengineeringsolutionisavailable,eitherearplugsorearmuffscanbeused.

Activitiessuchastheerectionordismantlingofformworkmayinvolveveryloud,metalonmetalimpactnoises,suchasusinghammersonmetal.Suchnoisecandamagehearingimmediatelybecauseofitshighimpulsivenoiselevel.Otherloudnoise,suchasthatcreatedwhenusingacircularsaw,cangraduallydamageaperson’shearingthroughlongerperiodsofregularexposure.

The use of the hearing protectors must be enforced where a risk assessmentidentifiesthemasthepreferredoptiontocontroltherisk.

     

2m  

minim

um  

Fig.  14  –  Height  of  perimeter  screen  for  protection  from  falling  objects  on  the  ground  at  building  step-­‐in  

 

Standard  950  mm  Hand  rail  

Maximum  Angle  

No-­‐Go  Area  without  protection  from  

falling  objects  

Step-in width – W metres

Lift

Hei

ght –

H m

etre

s

Figure 14 – Height of perimeter screen for protection from falling objects on the ground at building step-in

Edge of “Step-in” structure

Perimetercontainment

screen

Lift

Heig

ht –

H m

etre

s

2 m

min

imum

Step-in width – W metres

no-go AreAwithout protection from

falling objects

Maximumangle 45º

standard 950 mmhand rail

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Often,constructionsitemanagementimposesablanketuseofhearingprotectionacrossthesiteatalltimes.Forformworkactivities,protectionagainstNIHLbywearinghearingprotectorsisoftentheonly option.

8.2 DusT AnD ATmosPHerIc conTAmInAnTs

Division17–VentilationoftheOHSWRegulationsdescribesobligationsthatmustbemetforatmosphericcontaminants,includingsilica dust.

Whileconcreteitselfisnotahazardoussubstance,highlevelsofsilicadustcanbeproducedduringformworkprocesses.Silicadustisahazardoussubstancegeneratedwhenpowertoolscut,grind,chip,scrape,crushorblastmaterialssuchasconcrete.Silicadustmayalsobecreated,toalesserdegree,bysweepingorcleaningwhendismantling building equipment or during demolition work.

The visibility of dust does not necessarily provide an accurate measureofthedegreeofrisk.Highlyvisibledustcausedbyearthmoving equipment on building sites or other earthworks sites is unlikelytocontainhazardouslevelsofrespirablesilicadust.However,silicadustproducedbyotheractivitiesmaybeathazardouslevelseven though it is barely visible.

Allreasonablestepsmustbetakentominimisetheexposuretosilicadust.Silicadustthatisgeneratedduringformworkcanbecontrolled by:

• usingdustextractionorawetprocessasadustsuppressant engineering control• providingrespirators(asalastresort)wheredustislikelyto exceed permissible levels.

8.3 mAnuAl TAsks

In2008/09,thereweremorethan2,270workerscompensationclaims in the construction industry. These resulted in more than $13.3millionincompensationcostsandover38,000daysoflosttime.Theindustry’suninsurablecostsassociatedwiththeseinjurieswouldhaveamountedtomorethan$53million.

Oftheinjuries,730(32%)weremusculoskeletalinjuriesfrommanualtasks.Thecostofcompensationfromtheseinjurieswas$5.3million(41%oftotalcosts)andmorethan17,700workingdayshavebeenlost(47%oftotallosttime).Theuninsurablecosttotheindustrytodateformusculoskeletalinjuriesoccurringin2008/09hasamountedtomorethan$21.5million.

Inallitsactivitiessuchasplanning,transport,storage,erectionanddismantlingofformworkandscaffolding,theindustryneedstotake into account the risk of injury from manual tasks and develop strategiestoeliminate,orifthisisnotpracticable,atleastminimisethe risks from manual tasks.

The Approved Code of Practice for Manual Handling(availablefromtheSafeWorkSAwebsitewww.safework.sa.gov.au)provides

information about preventing or minimising exposure to risks that contribute to or aggravate work-related musculoskeletal disorders. There are also many other sources of information for solutions to manualtaskrisksavailablethroughwebsitesinallotherAustralianjurisdictions,andgloballyintheUK(www.hse.gov.uk),Europe(http://osha.europa.eu/en)andCanada(http://www.ccohs.ca/).

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APPenDIcesAppendix1:Definitions

bearer PrimaryhorizontalsupportmembersforaformworkdeckthatareplacedinU-headsontopofformworkframes.Bearersareusuallyconstructedfromtimberbutaresometimesconstructedfrommetal,such as in the case of some modular formwork systems.

cell Partofaslipform,jumpformorcrane-liftedformwhereworkersarerequired to carry out work. The cell will generally be enclosed by all sides and a bottom surface.

Certificateofcompetency Adocumentthathasbeenissuedbyalicensingauthoritypriortothe introduction of the National Standard for Licensing Persons Performing High Risk Work authorising a person to perform one or more classes of high risk work.

class of high risk work AclassofworklistedintheSchedule–LicenceClassesandDefinitions,oftheNational Standard for Licensing Persons Performing High Risk Work.

competent person In relation to performing an inspection or other task for a control measure–isapersonwhohasacquired,throughtraining,qualificationsorexperience,theknowledgeandskillstodotheworkinasafeway,including: (i) soundknowledgeofrelevantAustralianStandards,codes of practice and other legislation; and (ii) soundknowledgeof,andcompetencein,therisk managementprocessforerecting,alteringand dismantlingformwork,including– •hazardidentificationandriskassessment •measurestocontrolexposuretorisks •safeworkpracticesandprocedures,and •howtoplanandprepareformwork.

containment sheeting Aprotectivestructurefixedtotheperimeterofthebuilding,structureor working platform to contain objects and prevent them from falling.

edge protection Abarriererectedalongtheedgeof–• abuildingorotherstructure• anopeninginasurfaceofabuildingorotherstructure,or• araisedplatformto prevent a person falling.

engineer Inrelationtotheperformanceofatask,meansapersonwho– (a)isaregisteredprofessionalengineereligiblefor corporatemembershipofEngineersAustralia,and (b)iscompetenttoperformthetask.

false deck Adeckdesignedtopreventworkersfalling2mormoreand/orprovided as a working platform.

form Anobjectusedinthecastingofconcretefloors,wallsorcolumnsthat has part of its surface in contact with the concrete during the initial concrete curing process.

formwork designer Apersoncompetenttodesignbasicornon-basicformworksystems,butmayonlycertifybasicformwork.Tocertifynon-basicformwork,theFormworkDesignermustbeanengineerexperiencedinformwork design.

formwork frame Astructuralassembly,anumberofwhichareusedtosupportaformworkdeck.Bearersareplaceddirectlyontheseframes.

Horizontal member Anyhorizontalmemberofaformworkorscaffoldframethatisprovided as stiffening for the frame and may also be used to support aworkingplatform(includestheterm‘transom’inreferencetoscaffolding).

Intermediate platform Aplatformatleasttwoplankswide,locatedlessthan2maboveacontinuous deck.

joist Asecondaryhorizontalsupportmemberfortheformworkdeckthatisplacedontopof,andatrightanglesto,thebearers.Joistsareusually constructed from timber but are sometimes constructed from metal,suchasinthecaseofsomemodularformworksystems.

metal deck Aformdeck,madeofsteelsheetsthatarenormallynotrecovered.

modular formwork Aformworksystemthatisspecificallydesignedandconsistsof components that are not intended to be used with other systems.

Perimeter edge Edgeprotectionthatisprovidedontheperimeteroftheprotectionformwork to be erected.(Note:Perimeteredgeprotectionwillpreventafallfromtheoutsideperimeter of the formwork but will not prevent internal falls through theformwork).

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Propping Slender structural members placed in a vertical position between two horizontal surfaces and used to support the upper surface. The proprietary term ‘acrow’ is often used to describe a prop. The height of propping is usually adjustable.

Vertical member A vertical structural member which may or may not form part of a frame, also known as a standard, prop or vertical tube.

Appendix 2: Training

Under the South Australian Occupational Health, Safety and WelfareAct 1986, Part 3, Section 19 – Duties of employers…“an employer must provide such information, instruction,training and supervision as are reasonably necessary to ensurethat each employee is safe from injury and risks to health”...

Anyone involved in erecting and dismantling formwork must betrained to perform their work in a manner that is safe and withoutrisks to health or safety, and must have evidence of their training.The employer must monitor their systems of work and, whennecessary, provide refresher training to ensure that safe practices arebeing followed.

The requirement for an employer to ensure that training is provided has been identified in several sections of this guide. Some of this training relates to specific competencies required under the legislation and must be conducted by a registered training organisation. For example:

• scaffolder• rigger• dogman• craneoperation.

Other duty of care training may be provided and delivered by manufacturers or suppliers of equipment and materials or, where resources are available, developed and delivered in-house by competent trainers. This includes training for:

• formworkconstructionsystems• modularworksystems• workingatheightharnesssystems.

Safe work method statements, developed by experienced workers and their supervisors, can form an excellent basis for introductory training for inexperienced or new workers in the following areas:

• erectingofalltypesofformwork• dismantlingofalltypesofformwork• layingofmetaldeck• slipformsandjumpforms.

Each site manager must assess training requirements and ensure that everyone on-site can competently and safely undertake their work without adversely affecting the health and safety of others.

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Appendix3:Sampleengineer’scertificationletters

Refertosection2.2.2Formworkdesigncertificationrequirements.

(A)Engineer’sCertificationLetter– no variation to design

………………………………….

………………………………….

………………………………….

………………………………….

Dear ……………………

Project……………………………………

I certify that the formwork system detailed below has been designed in accordance with AS 3610 – Formwork for Concrete and AS 3600 – Concrete Structures,andtheprojectdocumentationincludingthestructuralengineeringdrawingsandspecifications.The system is detailed on the drawings and documentation listed below.

Drawing number Drawing name

Specifications

Yoursfaithfully

SIGNATUREEngineer’sname

DocumentControlSystemNo.

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(B)Engineer’sCertificationLetter–variation to design

……………………………………

……………………………………

……………………………………

……………………………………

Dear ……………………

Project…………………………….

I certify that the variations to the formwork system detailed below have been checked and satisfy the AS 3610 – Formwork for Concrete, AS 3600 – Concrete Structureandtheprojectdocumentationincludingthestructuralengineeringdrawingsandspecification.

variation Details of variation of formwork system Project drawing number reference

Yoursfaithfully

SIGNATUREEngineer’sname

DocumentControlSystemNo.

33

Appendix 4: construction checklist

(Note: ‘#’ denotes an item that, if not passed by the competent person, must be referred to the engineer. All other items not passed by the competent person must be corrected on-site and certified by the competent person when he/she is satisfied.)

loads• Stackedloadlimitsareidentifiedforallstages?• Stackedmaterialsareonspreaders?# Willanyconstructionproceduresexceedthestackedloadlimit?

materials # Correctformmaterialsarebeingused?• Formfaceconditionissuitableforthefinishrequired?

formwork frames# Aretheformworkframesinthecorrectlocationand correctnumber?• Aretheytodimensionandwithintolerance?• Aretheyaccuratetoline,levelandplumb?

bracing/Props# Aretheredifferentpropsorbracestotheonesindicatedon theformworkdrawings?• Arethepropsplumb?• Arepropsstraight?• Arebaseplatesonadequatefoundations?• Areallloadscentrallyplaced?• Ifno,arealleccentricloadscertified?• Aresupportedelementswedgedandnailed?• Isthebracingcorrectandfirmlyconnected?

fixing• Isthenailing/screwingadequate?# Arethetiesthecorrecttype?# Aretheyonthecorrectgrid?• Areallties,clampsandboltstight?• Arewedgestightandnailed?# Areanyconnectionsbetweentraditionalformworkandmodular formworkcorrect?

back-propping# Istheback-proppingsystemcorrect?# Arethenumberoffloorsrequiredforback-proppingcorrect?# Hastheproppingbeencorrectlyreleasedandtightened,as specified,priortotheconcretebeingpouredabove?

cleanliness• Aretheformfacescleaned?• Isanydamagecorrectlyrepaired?• Isthecorrectreleaseagentinuse?• Isitbeingcorrectlyapplied?• Hasalldebrisbeenremovedfromwithintheform?

Watertightness• Areallformpaneljointsproperlysealedandcramped?• Aretheconstructionjointssealed?

concrete/concreting• Whatisthemaximumrateofplacementpermitted?• Aretheformsmaintainingline,level,plumb,shape,etc duringconcreting?

stripping• Whataretheminimumstrippingtimes?• Hastheprojectdesignerpermittedmodificationofthese?• Dotheproceduresenablestrippingwithoutdamagetoform orconcrete?• Aretheprovisionsconsistentwiththere-usetimesrequired?• Doesthecranehavethenecessaryslingsetctomovethe formsquickly?• Whatcuringmethodsaretobeusedoncetheformwork isremoved?• Isthestorageareafortheformworkorganised?

safety• Arethereadequateguardrails,handrails,walkways,signs,etc inposition?

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Appendix5:Samplestructural(pre-pour)certificate

Refertosection2.2.5On-sitecoordinationandverification

Engineer’s/Competentperson’sname:……………………………………………….…….Telephone:……………………………..

Address:…………………………………………………………………………………………………………………………

Fax:……………………………………………….

Mobile:…………………………………………… Date:……………………………..

Project:…………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………………………

Level:………………………………. Area:……………………….

Thisistocertifythatthe………………………..FormworkfortheaboveprojecthasbeeninspectedandisconsideredtobeadequatetosupportthedesignloadsinaccordancewiththerelevantAustralianStandardsincludingAS 3610 Formwork of Concrete.

The following items were included in the inspection:

Item condition Work required Details of remedial work required (circle) (circle)

Baseplates PASS FAIL No Yes

Framespacing PASS FAIL No Yes

Framebracing PASS FAIL No Yes

Frameextensions PASS FAIL No Yes

Bearersizeandspacing PASS FAIL No Yes

Joistsizeandspacing PASS FAIL No Yes

Propspacing PASS FAIL No Yes

Propbracing PASS FAIL No Yes

Eccentricloading PASS FAIL No Yes

Propinclination PASS FAIL No Yes

Timbercondition PASS FAIL No Yes

Steelcondition PASS FAIL No Yes

Nailsinplatesasrequired PASS FAIL No Yes

Columnframing PASS FAIL No Yes

Columnbracing PASS FAIL No Yes

Plywoodfixing PASS FAIL No Yes

……………………………………. …………………………………Engineer’s/Competent person’s name Signature

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Appendix 6: Defects commonly found in formwork systems sole plates(a) Notlevelledinoreccentricallyplaced(b) Inadequateload-carryingcapacityoftheground, or uneven bedding(c) Deteriorationwithtime,e.g.duetoweatherconditions(d) Deteriorationofload-carryingcapacityoftheground, e.g. washouts(e) Crushingduetoinadequateloaddistributionfromvertical andhorizontalmembers.

Horizontal supports(a) Foldingwedges,tapercuttotoocoarse,notproperlycleatedor cut from wet material(b) Inadequatelateralandtorsionbracing,e.g.betweentelescopic centres,centrescarryingheavyloadsoverlongspans,steel propssupportingheavyloadsat,ornear,maximumextension and between towers supporting independent spans(c) HorizontalmembersnotcentrallyplacedinU-heads(d) Inadequatesupportstocantilevers,e.g.strutssupportingdeep beam sides on the outer face of the structure(e) Inadequatebearingareastoverticalsupportsandundersideof principal members causing crushing(f) Inadequatesupporttopreventoverturningofdeepprincipal membersbecausestirrupsorU-headsomitted(g) Boltedtimberconnectionsnotstaggeredcreatingtendency to split out.

vertical supports(a) Inadequatebracingduringerection(b) Supportsnotplumb(c) Inadequatelateraltiesand/orverticalandplanbracing(d) Notiesbetweenstandardsatpointofloading(mostimportant wheretelescopiccentresarebeingsupported)(e) Incorrectprovisionofpropsfromfloortofloor(f) Lackofrigidityofscrewconnectionsduetoover-extensionor lack of bracing(g) Incorrectpinsusedinadjustablesteelprops,e.g.nails,mild- steel bolts and reinforcing bars used(h) ScaffoldU-headsorsupportsomittedorotherwiseeccentrically loaded without allowance having been made for this condition(i) Bearingplatesdistorted(topandbottomplatesofsteelprops)(j) Inadequateordiscontinuousbracingtoscaffold(k) Basejacksover-extended.

general(a) Excessivetolerancesinconstruction(b) Failuretochecktightnessofbolts,wedges,etc(c) Failuretocontrolverticalrateofplacementofconcrete(d) Failuretocontrolplacementofconcrete,causinguneven loading of forms(e) Inadequateallowanceforupliftofconcreteunderinclinedforms(f) Inadequateallowancefortheeffectsofvibrationonjoints(g) Inadequateallowanceforstressesinducedbypre-stressing, temperature and moisture movements(h) Noallowanceforwindloading(i) Noallowancefortheeffectofvibrationonties,struts,braces, and wedges(j) Unrealisticassessmentofstressesduetoover-simplificationof design assumptions(k) Unequalloaddistributionbetweentwoormorememberscarrying a common load(l) Penetrationstometaldeckstobesupported.

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