1 - intro to rc detailing - k

7/28/2019 1 - Intro to Rc Detailing - k

1/23

Introduction

What needs detailing & Resources

Reinforced concrete

Steel reinforcement why it is needed

Material Concrete

Material Steel reinforcement

Which part of a member is in tension?

Designer information to detailer

RC Detailing - communication

Introduction


Reinforced concrete


Material Concrete






2/23

Concrete building structures

Flat Slab

Voided slabs

Beams

Frame options


Leeds Oncology Wing - Flat slab 350mm thick

8.1m x 8.1m grid


3/23


Structural elements

Foundations - Pad bases, Pile caps

Columns

Beams

Slabs

Walls

Structural drawings General Arrangement drawings:

Explain the shape and position of all the parts of the structure

They provide the detailer with the layout information required to

specify the steel reinforcement.

General arrangement drawings


4/23

Leeds Oncology Wing

Flat slab - reinforcement

Shear studs

Link shape 22

Leeds Oncology Wing

Column reinforcement Link shape 51


5/23

Leeds Oncology Wing

Column formwork

Formwork the mould

Column

Leeds Oncology WingRC Drawing Flat slab


6/23

Communication RC Drawing

Introduction


Reinforced concrete


Material Concrete





RC Drawing - Detailing a group of bars


7/23

Standard Method of DetailingStructural Concrete

Third edition 2006

Gives: Model details for structural

elements

Examples of typical RCdetails

Guidance consistent withEurocode 2

Model Detail MF1

SMD

Concrete Society


8/23

Specification NSCS, v4

1 Scope

2 Bibliography

3 Definitions

4 Execution Management

5 Falsework and Formwork

6 Reinforcement

7 Prestressed Concrete

8 In-situ Concrete - Finishes

9 Precast Concrete

10 Geometric Tolerances

Health & Safety


9/23

Introduction


Reinforced concrete Steel reinforcement why it is needed Material Concrete Material Steel reinforcement




Steel reinforcement Why it is needed

Concrete CompressionResistance - Good

Tensile strength zeroSteel reinforcement needed


10/23

Steel reinforcement Why it is needed

Analysis shows which part of a member is in tension

Reinforcement is designed to

carry these tensile forces

Material - Concrete

PUMP SKIP

Detail Min75 mm gap


11/23

Material - Concrete

Properties

Strength in Compression very good

Compressive strength class defines 28 day compressive strength

Compressive strength class

C32/40

Minimum characteristic cube strength

40 MPa

Minimum characteristic 150mm diameter by 300mm

cylinder strength

Letter for type of concrete

(C normal & heavyweight; LC lightweight)


12/23

Material - Concrete

Properties

Strength in Compression very goodCompressive strength class defines 28 day compressive strength

Strength in Tension for design = zero

e.g. C32/40


Properties

Characteristic yield strength, fyk = 500MPa (UK BS 4449:2005)

tensile and compressive strength

BS 4449:2005 has three ductility grades A, B & C

Notation of steel reinforcement, BS 8666:2005

www.ukcares.co.ukwww.uk-bar.org

e.g. H16

Nominal bar diameterLetter defines steel type


13/23

Notation of steel reinforcement

H A

B

C

Stainless steel

Defined by specifier

12mm,

Ductility16 to 50mm

16 to 50mm

S

X

BS 8666:2005

Reinforcement

SMD


14/23

Reinforcement

Supply:

Coil up to 16mm (2.5T)

Bar 12,14,15 and 18m

Practicalities:

12m maximum length H20 to H40

(12m H40 = 18 stone/ 118Kg)

9m maximum length H16 & H12

6m maximum length H10 & H8

Reinforcement Anchorage and

laps lengthsAnchorage and lap lengths

for bars in compression worst case

Ch 10. Detailing

Anchorage length = 40

Lap length = 61


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Detailing Fabrication tolerances(BS8666)

10mm minimum tolerancebetween bars

-5mm

+5mm

Example Two U-bars

Detailing Construction tolerances

(IStructE)

Member dimension minus

Nominal cover minus

Fabrication tolerances as required

Bending Schedule Dimensions -


16/23

Approximate Costs

Formwork &

Falsework

Concrete

Reinforcement

Material cost

Labour

Introduction


Reinforced concrete


Material Concrete






17/23

Which part of a member is intension?

Beams and slabs

FlexureThe vertical loads on a beam or slabcause it to bend.

The Bending Moment diagram shows which part of a member isin tension due to flexure, Top or Bottom.

Shear

Shear forces may require vertical steel in slabs.Beams require shear links

a lFtd

a l

Envelope of (MEd /z +NEd)

Acting tensile force

Resisting tensile force

lbd

lbd

lbd

lbd

lbd lbd

lbd

lbdFtd

Shift rule

Bending moment diagram

Bending moment diagram continuous member

Top bars in tension

Bottom bars in tension


18/23

Shear force diagram

Shear

Shear forces may require vertical steel in slabs.

Beams require shear links

Shear Link shape 51

Shear force diagram

Shear

Shear forces may require vertical steel in slabs.

Beams require shear links


19/23

Introduction


Reinforced concrete


Material Concrete






Steel areas at critical locations

From calculation sheets

Marked up General Arrangement drawings

Proforma sheet

Designer provides sketch of detail


20/23


Steel areas at critical locations - From calculation sheets


Steel areas at critical locations - From calculation sheets


21/23


Steel areas at critical locations Marked up GA


Steel areas at critical locations Proforma sheets


22/23


Concrete grade compression strength class eg C28/35

Nominal Cover to bars

Nominal cover, cnom(RC Drawing)

Minimum cover, cmin(Durability & Bond)

Allowance for deviation, cdev

Axis distance, aFire protection

Introduction


Reinforced concrete


Material Concrete






23/23

Communication - Designer to construction site

Design

Find location &extent of tensionin members.

Determine areaof steel to resisttension.

Construction

Fix steelreinforcement.

Place concretein members.

RC Detailing

RC Drawings + Bar Schedule

Call up bars. List every barBar marks. mark.Bar location. BS 8666: 2005

RC Detailing

Bar Schedule Steel supplier

Cutting & bending dimensions

1 - intro to rc detailing - k

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