Mechanical properties of fiber reinforced lightweight concrete composites

Hybrid composites with variable strength/toughness properties can be manufactured using combinations of brittle or ductile mesh in addition to brittle and ductile matrix reinforcements. The bending and tensile properties of thin sheet fiber cement composites made from these mixtures were investigated. Composites consisted of a woven mesh of either polyvinyl chloride (PVC) coated E-glass or polypropylene (PP) fibers for the surface reinforcement. In addition, chopped polypropylene, acrylic, nylon, and alkali-resistant (AR) glass fibers were used for the core reinforcement. It is shown that by controlling fiber contents, types, and combinations, design objectives such as strength, stiffness and toughness, can be achieved. Superior post-cracking behavior was measured for composites reinforced both with glass mesh and PP mesh. Load carrying capacity of PP mesh composites can be increased with the use of 1% or higher chopped PP fibers. Glass mesh composites with short AR glass fibers as matrix reinforcement indicate an increased matrix cracking strength and modulus of rupture. Combinations of PP mesh/short AR glass did not show a substantial improvement in the matrix ultimate strength. An increased nylon fiber surface area resulted in improved post peak response.