Detailing to BS 8110

RC Detailing to BS 8110 S A Karunaratne 29-01-2013

(I)

Paper & Envelope Sizes & Drawing Sizes

(II)

Title Panel, Scales, Line Thickness & Abbreviations

(III)

Layouts, Axes & Grid Lines & G A Drawings

(IV)

Levels & Dimensions

(V)

Slabs & Beams

(VI)

Columns & Walls

(VII)

Staircases

(IIX)

Corbels & Nibs

(IX)

Footings, Piles & Pile Caps

(X)

Bar Bending Schedules

What is presented ?

(XI) What should be done & what should not be done

Paper & Envelope sizes ISO 216 sizes

ISO 216 sizes

ISO 269 sizes

(mm x mm)

(mm x mm)

(mm x mm)

Paper - A Series

Paper - B Series

Envelopes - C Series

A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10

841 594 420 297 210 148 105 74 52 37 26

x x x x x x x x x x x

1189 841 594 420 297 210 148 105 74 52 37

A0 aspect ratio is 1 : √2 & area is 1m2

B0 1000 x B1 707 x B2 500 x B3 353 x B4 250 x B5 176 x B6 125 x B7 88 x B8 62 x B9 44 x B10 31 x

1414 1000 707 500 353 250 176 125 88 62 44

B0 is 1m to √2m & GM between A series same number and one lower

C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10

917 648 458 324 229 162 114 81 57 40 28

x x x x x x x x x x x

1297 917 648 458 324 229 162 114 81 57 40

GM between B series same number & A series same number

Sizes of Paper A & B & Envelopes C are defined by halving preceding size

3 A1

A0

5

6

4

A2

Size A Paper fits to same size Envelope – e.g., A4 to C4 Size B Paper fits to one number lower size Envelope – e.g., B4 to C3

Notes

MA2-4 MA0-1

M A0-1 = 20 Minimum M A2-4 = 10 Minimum Design stage changes

Margin Thickness = 0.5mm minimum

Revisions

Title Panel

M L = 20mm minimum

105

Drawing Margins & Title Panel

75 - 200

MA2-4 MA0-1

Title Panel should include: Main & Associated Consultants (If Applicable) Project Title Client’s Name (If Applicable)

Drawing Title Drawn by (Name) Designed by (Name) Checked by (Name & Signature) Approved by (Name & Signature) Scales & drawn Scale Office Job Number

Drawing Number & Space for Revision Suffix Date of Drawing Office of origin of Drawing Copy Right Protection Statement

Recommended sizes of drawings General Arrangement Drawings (G A) Reinforcement Drawings Details

: A1 : A1 : A3 & A4

Recommended scales GA

1 : 100

Beam & Column elevations 1 : 50

Wall & Slab details

1 : 50

Beam & Column sections

1 : 20

Recommended thickness of lines Dimensions & center lines Concrete outlines & G A drawings

0.25mm 0.35mm

Concrete outlines & R/F drawings Links, hoops & cross-ties

0.35mm 0.35 – 0.7mm

Main R/F bars

0.7mm

Changes & Revisions should include: Suffix; numeral for changes – 1, 2, 3, ----- & letters for revisions – A, B, C, -Brief description of revision

450

Revision made by (Name & Signature) Date of revision Cloud revised details

A

Beam depth changed 300 to 450

Revision Description

250

SAK Made by

24-06-2008 Signature

Date

Notes should include: Cross references to GA Drgs Cross references to connected Detail Drgs List of abbreviations Grade of concrete

(i) Main bar size minus link size (40 -10) = 30mm

(ii) Exposure – moderate - C40 – 30mm Cover to R/F (iii) 1 ½ hour fire resistance – 20mm

(iv) 20 mm aggregate size – 20mm

30mm

BS 8110 – Exposure conditions Specify nominal cover to all reinforcement including links o Mild – Protected from weather or aggressive conditions o Moderate – Sheltered from severe rain, subject condensation, continuously under water, in contact with non-aggressive soil o Severe – Exposed to severe rain, alternate wetting and drying or severe condensation o Very severe – Exposed to sea water spray, corrosive fumes o Extreme – Exposed to abrasive action or machinery or vehicles

BS 8110 – Table 3.4 Nominal cover to meet durability requirements Condition of exposure

Nominal cover

Mild Moderate Severe Very severe Extreme Max. w/c ratio

mm

mm

mm

mm

mm

0.65

0.60

0.55

0.50

0.45

Min. cement (kg/m3)

275

300

325

350

400

Lowest concrete grade

C30

C35

C40

C45

C50

25 -

20 35 -

20 30 40 50 -

20 25 30 40 60

20 20 25 30 50

Cover may be reduced to 15mm aggregate not exceeding 15mm Table is for normal-weight aggregate of 20mm nominal max. size

BS 8110 – Table 3.5 Nominal cover to meet fire requirements Fire resistance

Nominal cover Beams Floors Ribs Columns SS Cts SS Cts SS Cts

h

mm

mm

mm

mm

mm

mm

mm

0.5

20

20

20

20

20

20

20

1

20

20

20

20

20

20

20

1.5

20

20

25

20

35

20

20

2

40

30

35

25

45

35

25

3

60

40

45

35

55

45

25

4

70

50

55

45

65

55

25

Cover may be reduced to 15mm aggregate not exceeding 15mm Additional measures are required to reduce spalling Cover to main R/F given in Tables 4.2 & 4.3 is considered.

BS 8110: Part 1: Section 7.3

COVER TO REINFORCEMENT Reference to EuroCodes BS EN 206-1 Concrete – Part 1: Specification, Performance, production & conformity

 BS 8500-1 Concrete – Part 1: 2002 Method of specifying & guidance for the specifier  BS 8500-2 Concrete – Part 2: 2002 Specification for constituent materials & concrete ; BS 5328 withdrawn 1-12-2003

A List of Abbreviations ABR

= Alternate Bar Reversed

Blk

= block work

Bw

= Both ways

B

= Bottom

Bwk

= Brick work

Crs

= Centres

¢

= Centre Line

dia or F = Diameter

drg

= drawing

EF

= Each face

EGWL = Existing ground water level

EL

= Existing level

FF

= Front face

FFL

= Finished floor level

FS

= Full size

H

= High tensile steel

horiz

= Horizontal

R

= Mild steel / Round bars

NF

= Near face

NTS

= Not to scale

pkt

= pocket

RC

= Reinforced concrete

RRM

= Random rubble masonry

SFL

= Structural floor level

T

= Top

vert

= vertical

Recommended practices in drawing preparation Site Plan drgs

: should show North Point

All other drgs

: to site plan orientation

Continuation drgs

: provide key plan / portion covered

N

provide reference continuation drg numbers

R/F drgs

: show large openings; upto 150 x 150 mm &

150F holes need not be shown; but refer to drgs As-Built or Record drgs: amend original drawings as constructed

1

N

7000

6000

E A 6000

6000

Road

6000

Access

D

C

B 6000

6000

1

7000

C

B 6000

2

A

Plan - Detail Main Road

LAYOUT PLAN

E

D

DETAIL PLAN

ORIENTATION OF DRAWINGS

6000

1

1

2

3

B

A

Key Plan

A

Floor slab A1 - 22nd Level

Detailed Area is marked in Key Plan

Grid lines & Axes LUC

A

LLC

Beam reference is panel LLC column identification & a suffix say A11, A12 etc

A21

Columns A1, A2 are at intersection of A & 1, A & 2 etc

A12

3 C

C22 B23

B22

B31

B12

B

A11

Grids commence at LUC and right

C12

2 C

A23

A31

C C

B21

1 C

B11

Axes commence at LLC and up. Omit I and O

A22

Structural General Arrangement Drawing (BASED ON ORIGINAL DRAWING BY OTHERS)

GENERAL ARRANGEMENT DRAWING

C25/ 30

Concrete C40/50

C35/45

C32/40

C25/30

C20/25

Concrete Grades in High Rise Buildings

Building Structures are Designed from top (roof) to bottom (foundations) Building Structures are usually constructed from foundations to roof Therefore typical details should be referred from bottom (foundation level) to top (roof level) and not from top to bottom to avoid confusion at construction stage.

Levels

in metres

(a) For major works use Ordnance Survey (OS) datum (b) Civil & major Building works use a TBM or transferred OS datum (c) For minor works use a job datum wrt a suitable fixed point On plan levels are indicated within a rectangle and preferably described SSL 155.075 On Elevations & Sections project beyond drawing with closed FFL SSL arrowhead 155.075

50

Dimensioning recommendations Unit for layouts and levels is metre; say 2.450, 128.400, 9.125m Unit for R/F and sections is millimeter; say 5, 35, 2575 (can avoid writing mm and dimension to whole mm) Place dimensions above and not through dimension lines or not inside details. Place to view from bottom or RHS of drg.

G A drgs should give setting out dimension & sizes of members

Dimensions in R/F drgs only to show correct location of R/F.

GENERAL ARRANGEMENT DRAWING SHOWING DIMENSIONING AND LEVELS

SLABS 1 BAR CURTAILMENT SIMPLE RULES

SLABS 2 BAR ANCHORAGE

TYPICAL ONE-WAY SPANNING SLAB

TYPICAL

TWO-WAY SLAB

SLAB R/F ARRANGEMENT

1

2

3

4

5

6

7

8

H G F E

Open courtyard D C B A

From experience recommend continuous nominal top R/F in: (1) All coloured panels preferably in open courtyard situations (2) All the slab panels in a roof to avoid shrinkage cracks

TYPICAL FLAT-SLAB PANEL 1

Flat Slab Raft Foundation & Column R/F Starter Bars

TYPICAL FLAT-SLAB PANEL 2

Flat Slab Raft Foundation with a Deep Beam at Change of Levels

Trimming of holes in normal slabs 1 Conditions

l = length w = width (a) wras - max = 1000 ps = parallel to span (b) wmin - used = w1 = 250 (assume) lps lps used = unsupported lps edge distance (c) lps - max = 0.25 l x = 1000 wa-i wras w1 = = ras = right angle to span (d) wtotal - max = 0.25 l y = 1500 wmin - used (e) Small holes with sides (F ) = 250 furnish diagonal bars top and bottom.

(h) In group of holes within 500 or less treat as single hole and trim as in (f); but bars should pass alongside where possible. (i) In group of holes within 500 and 1000 treat as single hole and trim as in (f) and (g).

® Cutting element bars passing through hole and furnishing a stirrup as a trimmer is totally wrong

Joints in Slabs 1 Control joints a retooled, sawed, or pre-moulded joints to allow for shrinkage of large concrete areas.

Control joints create a weakened section that induce cracking to occur along the joint, rather than in a random fashion. Isolation joints provide a separation between a slab on grade and columns or walls, so that each can move independently.

Expansion Joints 2

In a 100mm thick concrete walkway, what is the typical spacing for expansion joints? 6m on center accommodates movement due to both expansion and contraction

EXPANSION JOINTS 3

BEAMS 1 BAR CURTAILMENTS SIMPLE RULES 1

BEAMS 2

BEAMS 3 ANCHORAGE & LAP LENGTHS

Beam R/F Detailing Methods (i) If pre-assembled main R/F, hanger bars & links stopped 50mm short of face of support & splice bars used at supports.

(ii) If assembled at works - Span main bars lapped at or near the support. Link support bars lapped with ends of top main bars. (iii) Max. link space 0.75d longitudinal & 150mm horizontal space between tension bars (iv) Max. area Asc or Ast = 0.2 & Ast >= 0.13 (V) Maxim. Clear Distance between tension bars ab = hagg +5

Min. distance between bars

Bar curtailment not shown completely Sometimes stirrup arrangement not shown

Correct & unacceptable beam labeling

150

450

750

sb

450

b = 500 >1000 for EC2

b =500

ab 2%; Max. bar space >= 16 x vertical bar size

WALL VERTICAL R/F INSIDE & HORIZONTAL R/F OUTSIDE

DETAILS OF WALLS

R/F of wall showing horizontal bar placement in outer layer

WALL R/F ASSEMBLY

RETAINING WALL DETAILS SHOWS OUTER HORIZONTAL R/F

500T16-02-250 NF

500T16-02-250 NF

500T16-01-250 NF

12T10-04-200 NF

12T10-05-200 FF

500T16-01-250 NF

12T10-05-200 FF

500T12-03-250 FF

500T12-03-250 FF

12T10-04-200 NF

Correct & unacceptable labeling of wall R/F

STAIRCASE R/F DETAILS

DETAILS OF STAIRCASES

Ast- Main TR; Main tensile R/F. Large bend required on plan

Ast- Main TR; Main tensile R/F. Large bend required as in elevation

Two column links close to corbel top

Ast - Main TR welded to plate or cross bar

Two column links close to corbel top

DO NOT BEND THIS WAY Tension lap

Compression anchorage

Tension lap

Ast - Horiz >= 50% of Ast - Main TR

Compression bars. Area >= 1000mm2/metre of width of corbel

Compression anchorage

Ast - Horiz >= 50% of Ast - Main TR

Compression bars. Area >= 1000mm2/metre of width of corbel

When main tensile R/F