adriandetailingreinf2014.pdf

STRUCTURAL DESIGN:

DETAILING OF REINFORCEMENT

Reinforcement for a Floor Slab

Reinforcement for a Circular Column

Reinforcement for an Elevated Section of Motorway

This lecture will cover:

• Properties of reinforcement

• Cover to reinforcement

• Spacing of reinforcement

• Connecting reinforcement

• Worked example

THERE ARE SIX TYPES OF STEEL REINFORCEMENT

SPECIFIED IN BS 8666 : 2005

For diameters ≤ 12mm, Grade B500A, Grade B500B or Grade B500C conforming1

H

For diameters >12mm, Grade B500B or Grade B500C conforming to BS 4449:20052

Grade B500A conforming to BS 4449:2005 A

Grade B500B or Grade B500C conforming to BS 4449:2005 B

Grade B500C conforming to BS 4449:2005 C

A specified grade and type of ribbed stainless steel conforming to BS 6744:2001 S

Reinforcement of a type not included in the above list having material properties that are defined in the design or contract specification.

X

PROPERTIES OF TYPE ‘H’ STEEL REINFORCEMENT

Nominal dia. (mm)

8 10 12 16 20 25 32 40

Max. O/A dia. (mm)

10 12 14 19 23 29 37 46

Mass

( kg/m ) 0.40 0.62 0.89 1.58 2.47 3.85 6.31 9.86

Details of Steel Reinforcement

PROPERTIES OF STANDARD FABRIC [ Standard size - 4.8 m x 2.4 m ]

Fabric reference

Longitudinal bars Cross bars

Mass Nominal bar size

Pitch Area Nominal bar size

Pitch Area

(mm) (mm) (mm2/m) (mm) (mm) (mm2/m) (Kg/m2)

Square fabric:

A393 10 200 393 10 200 393 6.16

A252 8 200 252 8 200 252 3.95

A193 7 200 193 7 200 193 3.02

A142 6 200 142 6 200 142 2.22

Image of Mesh Reinforcement

Minimum Bending Radii

Nominal dia. ( mm ) Min radius ( mm )

8 16

10 20

12 24

16 32

20 70

25 78

32 112

40 140






• Worked example

MAINTAINING COVER TO REINFORCEMENT:

• The nominal cover to reinforcement 'cover' will have

been selected during the design stage - this distance

must be maintained during fabrication

• In order to do this, spacers are used – these can be

either concrete or plastic

Examples of Plastic and Concrete Spacers for the Bottom Face of Structural Member

http://www.anchor-bay-direct.co.uk/images_products/clip-chair-spacers.jpg

http://www.anchor-bay-direct.co.uk/images_products/double-cover-spacers.jpg

Examples of Chairs for Structural Slabs

http://www.anchor-bay-direct.co.uk/images_products/meshfix-spacers.jpg

http://www.anchor-bay-direct.co.uk/images_products/Hoop Spacers.jpg

http://www.anchor-bay-direct.co.uk/images_products/deckchairs_1.jpg

Workforce Standing on Reinforcement During the Placing of Concrete

MAINTAINING COVER TO REINFORCEMENT

• The nominal cover to reinforcement 'cover' will have

been selected during the design stage - this distance

must be maintained during fabrication

• In order to do this, spacers are used - these can be either

concrete or plastic

• When selecting concrete spacers, care must be taken to

ensure that they are comparable in strength, etc. with

the surrounding conc. and that they do not contain any

substances that are harmful to conc. / steel rebar






• Worked example

SPACING OF REINFORCEMENT:

The basic principles of the spacing of reinforcement are:

• The concrete can be placed and compacted satisfactory,

• There will adequate bond between the reinforcement

and surrounding concrete

• The MINIMUM spacing is described as the clear

horiz./vert. distance between bars should not be less

than the greater of;

the diameter of the reinforcing bar [or their

equivalent size if they are in bundles],

The maximum size of the aggregate + 5mm, or 20 mm

SPACING OF REINFORCEMENT - MINIMUM:

The greater of; the dia. of the bar; max. size

of the aggregate + 5mm; or 20mm.

The greater of; the dia. of the bar; max. size

of the aggregate + 5mm; or 20mm.

SPACING OF REINFORCEMENT:

If there is insufficient space for the bars to be placed

individually they can be bundled together. There are

accepted arrangements/shapes for these bundles:

Acceptable Shapes

Unacceptable Shapes

CONNECTING REINFORCING BARS:

There are three methods of connecting steel reinforcing

bars:

• Mechanical couplers

• Lap lengths

• Welding - although it is permitted in EuroCode 2 it

should be avoid where possible






• Worked example


Apart from on the very small projects, reinforcing bars

often need to be joined together. The reasons for this

include;

to extend their length

to change their shape in situations where it is

impractical to provide anchorage

At discontinuities in slabs/walls (i.e. starter bars)

Reinforcement for a Concrete 'Upstand' with Starter Bars projecting from Previously Cast Slab

High-visibility Covers for Exposed Starter Bars



bars:


• Lap lengths



A Mechanical Connector for Steel Reinforcement in Tension

A Mechanical Connector for Steel Reinforcement in Compression



bars:


• Lap lengths



Design Anchorage and Lap Lengths

Strength of concrete (N/mm2)

Diameter of reinforcing bar (mm)

8 10 12 16 20 25 32 40

25 Anchorage length 200 250 300 400 500 625 800 1000

Lap length 425 530 640 850 1060 1325 1700 2120


Lap length 385 480 580 770 960 1200 1540 1920


Lap length 355 440 530 705 880 1100 1410 1760


Lap length 305 380 460 610 760 950 1220 1520

GENERAL NOTES ABOUT CONNECTING REINFORCING BARS:

• Joints should be placed away from points of high stress,

i.e. outside the middle third of simply supported

members or at points of contra-flexure in continuous

members

• In situations where there are several adjacent joints, i.e.

in a reinforced concrete slabs, the joints should be

staggered






• Worked example

Extract of a Bar Bending Schedule

Shape Codes - Required for the Detailing of the Steel Reinforcement

3000 mm

350

mm

250 mm

350

mm

DIMENSIONAL ELEVATION SECTION A - AA

A

ELEVATION

AA

SECTION A - A

ELEVATION SECTION A - A

AA

U - BARS

2H16 - 022H16 - 02

U - BARS

01

01

03

01

01

4H16 - 01

2 T + 2 B

16H10 - 03 - 200

01

01

01

01

02

02

02

02

AA

SECTION A-AELEVATION

NOTES : DRAWING TITLE : SCALE : DRAWN BY : CHECKED :

DRAWING No. :

LEEDSMETROPOLITAN

UNIVERSITY

RC DETAILS FOR

A SIMPLY SUPORTED BEAM

A. R. B.

1000 - 02

BENDING SCHEDULE

Job No.: 1234

Bar

sched

ule

ref.:

1234 _ 01

Prepared

by: A. R. B. Sheet No.: 01

Project: Simply supported R. C.

beam

Date

prepare

d:

Revision:

Client: Leeds Metropolitan

University Last revised: Status:

Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number

Length of each bar, L

Shape code

A B C D E / R Rev.

letter

Beam 01 H16 1 4 4 2800 00 2800

02 H16 1 4 4 1700 21 750 270

03 H10 1 16 16 1100 51 290 190 120

2800 mm

3000 mm

100 mm [ 30 mm cover + 'nominal' 70 mm ]30 mm cover

2940 mm

3000 mm

30 mm cover

Number of shear links: • Length of beam = 3000 mm • Nominal cover to reinforcement = 30 mm • Length of reinforcement cage = 3000 - 2 (30) = 2940 mm • Spacing of shear links = 200 mm • Number of spaces = 2940 mm / 200mm = 15 • Number of shear links = 15 + 1 = 16

BENDING SCHEDULE

Job No.: 1234

Bar

sched

ule

ref.:

1234 _ 01

Prepared



beam

Date

prepare

d:

Revision:



Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number


Shape code

A B C D E / R Rev.

letter

Beam 01 H16 1 4 4 2800 00 2800

02 H16 1 4 4 1700 21 750 270

03 H10 1 16 16 1100 51 290 190 120

BENDING SCHEDULE

Job No.: 1234

Bar

schedule

ref.:

1234 _ 01

Prepared



beam

Date

prepared: Revision:



Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number


Shape code

A B C D E / R Rev.

letter

Nearest 25 mm Nearest 5 mm

BENDING SCHEDULE

Job No.: 1234

Bar

sched

ule

ref.:

1234 _ 01

Prepared



beam

Date

prepare

d:

Revision:



Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number


Shape code

A B C D E / R Rev.

letter

Beam 01 H16 1 4 4 2925 00 2925

02 H16 1 4 4 1700 21 750 270

03 H10 1 16 16 1100 51 290 190 120

2800 mm

3000 mm

100 mm [ 30 mm cover + 'nominal' 70 mm ]30 mm cover

2940 mm (nearest 25 mm = 2925 mm)

3000 mm

BENDING SCHEDULE

Job No.: 1234

Bar

sched

ule

ref.:

1234 _ 01

Prepared



beam

Date

prepare

d:

Revision:



Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number


Shape code

A B C D E / R Rev.

letter

Beam 01 H16 1 4 4 2925 00 2925

02 H16 1 4 4 1700 21 750 270

03 H10 1 16 16 1100 51 290 190 120

Lap length [ 610 mm for H16/Grade C40 Concrete ]

30 mm [ cover] + 10 mm [ dia of link ]

350 mm

270 mm

30 mm [ cover] + 10 mm [ dia of link ]

Lap length [ 610 mm for H16/Grade C40 Concrete ]

L = A + B + C - r (min. bending radius) - 2d (diameter) = 610 + 270 + 610 - 32 - (2 * 16) = 1426 mm = 1450 mm

Nominal dia. ( mm ) Min radius, r ( mm )

12 24

16 32

20 70

25 78

BENDING SCHEDULE

Job No.: 1234

Bar

sched

ule

ref.:

1234 _ 01

Prepared



beam

Date

prepare

d:

Revision:



Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number


Shape code

A B C D E / R Rev.

letter

Beam 01 H16 1 4 4 2925 00 2925

02 H16 1 4 4 1450 21 610 270

03 H10 1 16 16 1100 51 290 190 120

250 mm

350 mm

BENDING SCHEDULE

Job No.: 1234

Bar

sched

ule

ref.:

1234 _ 01

Prepared



beam

Date

prepare

d:

Revision:



Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number


Shape code

A B C D E / R Rev.

letter

Beam 01 H16 1 4 4 2925 00 2925

02 H16 1 4 4 1450 21 610 270

03 H10 1 16 16 1100 51 290 190 120

30 mm [ cover]

290 mm

30 mm [ cover]

30 mm [ cover] 30 mm [ cover]190 mm

L = 2A + 2B + max (16 d, 160) = 2 ( 190 ) + 2 ( 290 ) + 16 ( 10 ) = 1020 mm = 1025 mm

BENDING SCHEDULE

Job No.: 1234

Bar

sched

ule

ref.:

1234 _ 01

Prepared



beam

Date

prepare

d:

Revision:



Member Bar

mark

Type and Size

No. of members

No. of bars in each

Total number


Shape code

A B C D E / R Rev.

letter

Beam 01 H16 1 4 4 2925 00 2925

02 H16 1 4 4 1450 21 610 270

03 H10 1 16 16 1025 51 290 190

adriandetailingreinf2014.pdf

Documents

spacing of reinforcement

s reinforcement

types of steel reinforcement

circular column reinforcement

floor slab reinforcement

nominal cover

grade b500b

grade b500a