Shear
Design aids for shear reinforcement
Slabs: this extract is from How to Design Concrete Structures using Eurocode 2 (page 27)
It is not usual for a slab to contain shear reinforcement, therefore it is only necessary to ensure that the concrete shear stress capacity without shear reinforcement (vRd,c – see Table 7A below) is more than applied shear stress (vEd = VEd /(bd)). Where shear reinforcement is required, e.g. for ribs in a ribbed slab, refer to Chapter 4.
Table 7 vRd,c resistance of members without shear reinforcement, MPa
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r I =
As/(bd)
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Effective depth, d (mm)
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≤200
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225
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250
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275
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300
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350
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400
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450
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500
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600
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750
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0.25%
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0.54
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0.52
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0.50
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0.48
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0.47
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0.45
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0.43
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0.41
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0.40
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0.38
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0.36
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0.50%
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|
0.59
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0.57
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0.56
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0.55
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0.54
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0.52
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0.51
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0.49
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0.48
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0.47
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0.45
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0.75%
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|
0.68
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0.66
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0.64
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0.63
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0.62
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0.59
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0.58
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0.56
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0.55
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0.53
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0.51
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1.00%
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0.75
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0.72
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0.71
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0.69
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0.68
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0.65
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0.64
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0.62
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0.61
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0.59
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0.57
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1.25%
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|
0.80
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0.78
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0.76
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0.74
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0.73
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0.71
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0.69
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0.67
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0.66
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0.63
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0.61
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1.50%
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|
0.85
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0.83
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0.81
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0.79
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0.78
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0.75
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0.73
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0.71
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0.70
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0.67
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0.65
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1.75%
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|
0.90
|
0.87
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0.85
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0.83
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0.82
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0.79
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0.77
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0.75
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0.73
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0.71
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0.68
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≥2.00%
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0.94
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0.91
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0.89
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0.87
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0.85
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0.82
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0.80
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0.78
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0.77
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0.74
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0.71
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k
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2.000
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1.943
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1.894
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1.853
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1.816
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1.756
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1.707
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1.667
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1.632
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1.577
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1.516
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Table derived from: vRd,c = 0.12 k (100rI fck)1/3 ≥ 0.035 k1.5 f0.5
ck
where k = 1 + R(200/d) ≤ 2 and rI = As /(bd) ≤ 0.02
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Note
- This table has been prepared for fck = 30.
- Where rI exceeds 0.40% the following factors may be used:
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fck
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25
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28
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32
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35
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40
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45
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50
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Factor
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0.94
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0.98
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1.02
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1.05
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1.10
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1.14
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1.19
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| |
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Note: Extract from How to Design Concrete Structures using Eurocode 2 (page 27, Table 7)
Beams
Procedure for determining vertical shear reinforcement in beams is shown in the following flow chart:
Shear theory
Note: Extract from How to Design Concrete Structures using Eurocode 2: Beams (page 34, Figure 5)
Table 7: Minimum and maximum concrete strut capacity in terms of stress
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fck
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vRd, max (cot Θ = 2.5), MPa
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vRd, max (cot Θ = 1.0) MPa
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25
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3.10
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4.50
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28
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3.43
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4.97
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30
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3.64
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5.28
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32
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3.84
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5.58
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35
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4.15
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6.02
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40
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4.63
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6.72
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45
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5.08
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7.38
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50
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5.51
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8.00
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Note: Extract from How to Design Concrete Structures using Eurocode 2 (page 34, Table 7)
How to Design Concrete Structures using Eurocode 2: Second edition
