Disclosed are structural materials including polymeric reinforcement
fibers that can provide added strength and fracture toughness to the
matrix. The polymeric reinforcement fibers are polypropylene-based
monofilament fibers or tape fibers exhibiting extremely favorable
mechanical characteristics for structural reinforcement including modulus
greater than 12 MPa and elongation less than about 10%. The disclosed
reinforced composite materials can exhibit desired average residual
strength values with less total fiber loading necessary to attain the ARS
values as compared to previously known polymer reinforced materials. Very
high strength and fracture toughness can be attained in the disclosed
composite materials.