What is FRP Rebar? Definition and Composition of FRP Rebar FRP, or Fiber Reinforced Polymer rebar, is a sturdy material that strengthens concrete buildings. It’s made of strong fibers, like glass, carbon, or basalt, mixed into a plastic-like base. These fibers make the rebar tough. The plastic base keeps the fibers together and protects them from things like rain or air. FRP rebar is a good choice...