• The design moment for a R.C. beam of b × h=250mm × 450mm is M=132kN·m, the concrete is of grade C40( α 1 =1.0 , f c =19.1N/mm 2 , f t =1.71N/mm 2 ) ,the steel is of grade HRB400.(f y =360N/mm 2 , ξ b =0.518, a s =40mm,). Calculate the area of the longitudinal tensile reinforcement of the beam . As=?