Tensile properties of strain-hardening cementitious composites containing polyvinyl-alcohol fibers hybridized with polypropylene fibers

Partially replacing polyvinyl-alcohol (PVA) fibers with polypropylene (PP) fibers in strain-hardening cementitious composites (fiber hybridization) modify certain mechanical properties of these materials. The hybridization based on the introduction of low-modulus hydrophobic polypropylene fibers improves the ductility and the strain-hardening behavior of the cementitious composites containing polyvinyl-alcohol fibers of different types (PVA-SHCC). Pull-out tests indicate that adding PP fibers increases the energy capacity of the hybrid composite with respect to the material containing only PVA fibers under tensile loading, and PP-fiber geometry (i.e., section shape and length) is a key factor in enhancing the strain capacity.