GATE Civil Engineering (CE) 2013 Solved Paper

As per IS 456:2000 for M20 grade concrete and plain bars in tension the design bond stress τ_bd 1.2 MPa. Further, IS 456:2000 permits this design bond stress value to be increased by 60% for HYSD bars. The stress in the HYSD reinforcing steel bars in tension, σ_s = 360 MPa. Find the required development length, L_d , for HYSD bars in terms of the bar diameter, ϕ .