Shear resistance

Shear will be taken as acting on the web of the section only.

When combined shear and torsion effects are to be considered, shear is to be checked using the variable strut inclination method. The angle 0 of the equivalent concrete struts is to be the same for both torsion and shear design.

The design shear resistance, V , with zero axial load is given by

Eqn 4.18

Table 4.8

Assuming 0.25°/o tensile reinforcement, p; = 0.0025 > 0.02

i/Rd1 = 0.34 x 1(1.2 + 40 x 0.0025) x 250 x 1440 x 10"3 = 159.1 kN < 355 kN Therefore shear reinforcement required.

Use the variable strut inclination method. The maximum design shear force, fRd2, to avoid web crushing is given by

w cd

Re-arranging gives

0 0

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