Find ratio for ultimate flexural strength at the centre – span section given that Aps = 3000mm2, d = 1150mm, fcu = 50n/mm2, bw = 150mm, fpu = 1500n/mm2, b = 600mm, ht = 250mm, design ultimate moment mud = 3400knm?

Correct Answer: 0.23
Aps = 3000mm2, d = 1150mm, fcu = 50n/mm2, bw = 150mm, fpu = 1500n/mm2, b = 600mm, ht = 250mm, design ultimate moment mud = 3400knm, according to BS: 8110-1985, Aps = (Apw+Apf) = Apf = 0.45×50(600-150)(250/1500) = 0.45xfcu(b-bw)(hf/fpu) = 1680mm2, Apw = (1300-1680) = 1320mm2, ratio(fpuApw/fcubwd) = (1500×1320/50x150x1150) = 0.23.