The bending strength of a concrete beam reinforced with a bar — FRP or steel — depends upon the compressive strength in concrete, and development of ultimate tensile strength in a bar, which in turn depends on the strain compatibility of the reinforcing bar with the surrounding concrete. The two materials (bar and concrete) must act in unison to develop full structural compositeness and efficiently resist external loads. Thus, the tension force resisted by the reinforcing bar, which induces bond stress, must be in equilibrium with the compression force resisted by the concrete.