design appendix ecs318 (final exam copy)

UiTM

2nd edition

DESIGN APPENDIX FOR STRUCTURAL CONCRETE

DESIGN

UiTM DESIGN APPENDIX FOR STRUCTURAL CONCRETE DESIGN

i

TABLE OF CONTENTS

CONTENT PAGE

1.0 Nominal Cover 1

1.1 Minimum concrete cover for durability 1

1.2 Nominal cover for concrete cast against uneven surfaces 3

1.3 Minimum concrete cover for fire resistance 4

2.0 Effective width of flange 7

3.0 Main reinforcement design 8

3.1 Design formula for rectangular sections 8

3.2 Design formula for flanged sections 9

4.0 Minimum and maximum area of reinforcement 10

5.0 Minimum spacing of bars 10

6.0 Shear reinforcement design 12

6.1 Shear resistance of concrete 12

6.2 Maximum shear resistance 12

6.3 Shear reinforcement 13

6.4 Minimum shear reinforcement 13

6.5 Spacing of shear reinforcements 13

7.0 Deflection control 13

8.0 Crack control 15

8.1 Beam 15

8.2 Slab 17

9.0 Curtailment rules for detailing 17

9.1 Simplified curtailments rules for beams 17

9.2 Simplified curtailments rules for slabs 18

10.0 Loading analysis 19

10.1 Continuous beam with approximately equal span

(moments and shears)

19

10.2 Continuous one way slab (moments and shears) 19

10.3 Simply supported two way slab (moments) 20

10.4 Two way restrained slab (moments) 20

10.5 Two way restrained 22

11.0 Column design 23

11.1 Slenderness and effective length 24

11.2 Slenderness ratio limit 26

12.0 Biaxial bending 26

12.1 Biaxial bending design formula 28

13.0 Moment due to imperfection 28

14.0 Column design charts 29

15.0 Pad footing design 33

16.0 Partial of safety 34

Table of reinforcements 35


1

1.0 NOMINAL COVER, Cnom

1.1 MINIMUM CONCRETE COVER FOR DURABILITY

Reference: BS EN 1992-1-1:2004 Section 4.1(Table 4.1)


2

Reference: BS EN 1992-1-1:2004 Section 4.4.1


3

Reference: BS EN 1992-1-1:2004 Section 4.4.1.3 (1)

1.2 NOMINAL COVER FOR CONCRETE CAST AGAINST UNEVEN SURFACES

Reference: BS EN 1992-1-1:2004 Section 4.4.1.3 (4)


4

1.3 MINIMUM CONCRETE COVER FOR FIRE RESISTANCE

Reference: BS EN 1992-1-2 : 2004 (Figure 5.2)

Reference: BS EN 1992-1-2 : 2004 (Table 5.5)


5




6

Reference: BS EN 1992-1-2 : 2004, Section 5.7.3


7

2.0 EFFECTIVE WIDTH OF FLANGE

Reference: BS EN 1992-1-1: 2004 Section 5.3.2.1


8

3.0 MAIN REINFORCEMENT DESIGN

3.1 DESIGN FORMULA FOR RECTANGULAR SECTIONS

Valid only for fck C50/60

Limiting value, Kbal = 0.167

If K ≤ Kbal, compression reinforcement is not required (singly reinforced section), and

If K > Kbal, compression reinforcement is required (doubly reinforced section) and

Check d’/d

If d’/d ≤ 0.171

If d’/d > 0.171

where


9

3.2 DESIGN FORMULA FOR FLANGED SECTIONS

Ultimate moment of resistance in flange, Mf

If M ≤ Mf, the neutral axis lies in flange

Therefore, design as a rectangular section.

If M > Mf, the neutral axis lies below flange

If M Muf , compression reinforcement is not required

If M > Muf , compression reinforcement is required


10

4.0 MINIMUM AND MAXIMUM AREA OF REINFORCEMENT

Reference: BS EN 1992-1-1: 2004 Section 9.2.1.1

5.0 MINIMUM SPACING OF BARS

Reference: BS EN 1992-1-1: 2004 Section 8.2


11

Reference: BS EN 1992-1-1: 2004 Table 3.1


12

6.0 SHEAR REINFORCEMENT DESIGN

Reference: BS EN 1992-1-1: 2004 (Section 6.2.1)

6.1 Shear resistance of the concrete, VRd,c


where,

Asl is the area of the tensile reinforcement, which extends (lbd + d) beyond the section considered

bw is the smallest width of the cross-section in the tensile area

6.2 Maximum shear resistance, VRd,max


a) If VEd ≤ VRd,max ( = 22)

Therefore, design the shear links

b) If VEd > VRd,max ( = 22)

Recalculate VRd,max ( = 45) and compare with VEd

If VEd ≤ VRd,max ( = 45),

If VEd > VRd,max ( = 45), redesign the section.


13

6.3 Shear reinforcement

6.4 Minimum shear reinforcement

6.5 Spacing of shear reinforcements

Reference: BS EN 1992-1-1: 2004 Section 9.2.2 (6-8)

7.0 DEFLECTION CONTROL

Reference: BS EN 1992-1-1: 2004 Section 7.4.1


14


15

8.0 CRACK CONTROL

8.1 BEAM

Reference: BS EN 1992-1-1: 2004 Section 7.3


16



17

8.2 SLAB


9.0 CURTAILMENT RULES FOR DETAILING

9.1 SIMPLIFIED CURTAILMENT RULES FOR BEAMS

Reference: BS 8110: Part 1: 1997: Figure 3.24

Figure 10.1(a): Simply supported beam


18

Figure 10.1(b): Continuous beam

9.2 SIMPLIFIED CURTAILMENT RULES FOR SLABS

Reference: BS 8110: Part 1: 1997: Figure 3.25

Figure 10.2(a): Simply supported slab

Figure 10.2(b): Continuous slab


19

10.0 LOADING ANALYSIS

10.1 CONTINUOUS BEAM WITH APPROXIMATELY EQUAL SPAN (MOMENTS AND

SHEARS)

Reference: BS 8110: Part 1: 1997: Table 3.5

Table 3.5 may be used to calculate the design ultimate bending moments and shear forces, subject to the

following provisions:

a) Characteristic variable action, Qk may not exceed characteristic permanent action, Gk.

b) Loads should be substantially uniformly distributed over three or more spans.

c) Variations in span length should not exceed 15% of the longest.

10.2 CONTINUOUS ONE WAY SLAB (MOMENTS AND SHEARS)


The ultimate bending moments and shear forces in one-way spanning slab may be calculated using the

coefficients in Table 3.12, provided that these conditions are met:

a) In a one-way spanning slab, the area of each bay exceeds 30 m2.

In this context, a bay means a strip across the full width of a structure bounded on the other two sides

by lines of support (Figure 3.7)

b) The ratio of the characteristic variable action and the characteristic permanent action does not exceed

1.25.

c) The characteristic variable action does not exceed 5 kN/m2 excluding partitions.


20

10.3 SIMPLY SUPPORTED TWO WAY SLAB (MOMENTS)


10.4 TWO WAY RESTRAINED SLAB (MOMENTS)



21


22

10.5 TWO WAY RESTRAINED SLAB (SHEARS)



23

11.0 COLUMN DESIGN

Reference: BS EN 1992-1-1: 2004 : Section 9.5


24

11.1 SLENDERNESS AND EFFECTIVE LENGTH

Reference: BS EN 1992-1-1: 2004: Section 5.8.3


25

with


26

11.2 SLENDERNESS RATIO LIMIT, lim


12.0 BIAXIAL BENDING



27


28

12.1 BIAXIAL BENDING DESIGN FORMULA

Reference: BS 8110: Part 1: 1997: Section 3.8.4.5

If

If

Equation for coefficient,

13.0 MOMENT DUE TO IMPERFECTION

Reference: BS EN 1992-1-1: 2004: Section 6.1 (4)

Reference: BS EN 1992-1-1: 2004: Section 5.2 (7)


29

14.0 COLUMN DESIGN CHARTS

Reference: Manual for the design of reinforced concrete building structure to EC2 (IStructE)


30


31


32


33

15.0 PAD FOOTING DESIGN

Area within perimeter = (bcol + 4d)2 – (4 - ) ( 2d)

2

Reference: BS EN 1992-1-1: 2004: Section 6.4.5 (3)

Reference: BS EN 1992-1-1: 2004: Section 6.2.2 (6)

d h

1.0 d

2.0 d Maximum shear Punching shear perimeter

= column perimeter + 4d


34

16.0 PARTIAL FACTOR OF SAFETY

Reference: BS EN 1992-1-1: 2004: Section 2.4.2.4


35

TABLE OF REINFORCEMENTS

Sectional Areas of Group of Bars (mm2)

Bar

Size

(mm)

Number of Bars

1 2 3 4 5 6 7 8 9 10

8 50.3 101 151 201 252 302 352 402 453 503

10 78.5 157 236 314 393 471 550 628 707 785

12 113 226 339 452 566 679 792 905 1020 1130

16 201 402 603 804 1010 1210 1410 1610 1810 2010

20 314 628 943 1260 1570 1890 2200 2510 2830 3140

25 491 982 1470 1960 2450 2950 3440 3930 4420 4910

32 804 1610 2410 3220 4020 4830 5630 6430 7240 8040

40 1260 2510 3770 5030 6280 7540 8800 10100 11300 12600

Sectional Areas Per meter Width for Various Bar Spacing (mm2/m)

Bar

Size

(mm)

Spacing of Bars

50 75 100 125 150 175 200 250 300

8 1010 671 503 402 335 287 252 201 168

10 1570 1050 785 628 523 449 393 314 262

12 2260 1510 1130 905 754 646 566 452 377

16 4020 2680 2010 1610 1340 1150 1010 804 670

20 3280 4190 3140 2510 2090 1800 1570 1260 1050

25 9820 6550 4910 3930 3270 2810 2450 1960 1640

32 16100 10700 8040 6430 5360 4600 4020 3220 2680

40 25100 16800 12600 10100 8380 7180 6280 5030 4190

Asw/s for varying stirrup diameter and spacing (mm)

Bar

Size

(mm)

Stirrup Spacing (mm)

85 90 100 125 150 175 200 225 250 275 300

8 1.183 1.118 1.006 0.805 0.671 0.575 0.503 0.447 0.402 0.366 0.335

10 1.847 1.744 1.57 1.256 1.047 0.897 0.785 0.698 0.628 0.571 0.523

12 2.659 2.511 2.26 1.808 1.507 1.291 1.13 1.004 0.904 0.822 0.753

16 4.729 4.467 4.02 3.216 2.68 2.297 2.01 1.787 1.608 1.462 1.34

Note: Asw is based on the cross sectional area of two legs of the stirrup

design appendix ecs318 (final exam copy)

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