Flexural behaviour of high strength basalt FRP rebar concrete

In this paper, the flexural behaviour of under-reinforced M70 grade basalt FRP rebar concrete beams in terms of first crack load, pre-cracking and post-cracking behavior, deflection pattern, crack development pattern and ultimate load carrying capacity is evaluated. Loads at first crack in basalt FRP rebars beams are higher than the normal steel rebar concrete beams confirming that basalt FRP rebars beams offer greater resistance to cracking. The ultimate flexural strength of basalt FRP rebar concrete beams have improved when compared to normal steel rebar concrete beams. First crack formation was delayed in basalt FRP rebar concrete beams due to which fatigue strength is increased which in turn increases the time taken for first crack occurrence and thereby increasing the load carrying capacity. The deflection at the mid span decreased in basalt FRP rebar concrete beams which indicates the improved flexural stiffness of the elements thereby reducing the structural member’s deformability, increasing strength and hence controlling deflection. Mid-span deflections at peak load reduced in basalt FRP rebar concrete beams. The ultimate deflection in case of basalt FRP rebar concrete beams is less than that of normal steel rebar concrete beams.