In limit state design, the design bond stress for deformed bars (conforming to IS 1786) for M20 concrete mentioned in IS 456 : 2000 is (in N/mm2units):
Design bond stresses for deformed bars in tension: For deformed bars conforming to IS 1786 these values shall be increased by 60%.
Design bond stress for bars in compression: For bars in compression, the values of bond stress shall be increased by 25%.
The bond stress for different grades of concrete as per different established provisions are as follows:
τbd = 1.2 × 1.6 = 1.92 N/mm2