Shear and Torsion

The February 1965 amendment to CP 114:1957 does not give recommendations for ultimate load design with regard to shear. Recent tests carried out at the Building Research Station have shown that the permissible shear stress given in Table 6 (CP 114), for beams without shear reinforcement, do not give a load factor consistent with that adopted for bending failure. In order to take advantage of redistribution of moments, the structural members must be proportioned to ensure that failure will occur in bending. The B.R.S. tests have led to recommendations given in the table below for permissible shear stresses in beams without shear reinforcement. The nominal shear stresses in CP 114 are given for comparison, a value of 7/8d being assumed for the lever arm.