Tensile behavior of fiber-cement hybrid composites containing polyvinyl alcohol fiber yarns

This paper presents the results of a study on fiber-cement hybrid composites containing high-performance continuous polyvinyl alcohol (PVA) fiber yams or rovings. Two types of hybrid composites were constructed using fiber combinations of PVA and glass (either continuous glass or 38-mm chopped strand), and PVA and fibrillated polypropylene networks. The tensile stress-strain behavior of these hybrids was studied, showing that the fibers, when used in a hybrid form, could result in superior composite performance compared to their individual fiber reinforced cements. The PVA-glass hybrid composite allowed similar or more favorable composite properties to be achieved at a lower addition of the high elongation fibers when compared to polypropylene-glass hybrids.(1) In comparison with the hybrids containing glass fibers (i.e., polypropylene-glass(1) and PVA-glass), the PVA-polypropylene hybrid was less efficient at small strains (say, up to 1 percent) because of the high elongation of both fibers at small strains. However the PVA-polypropylene combination was advantageous in achieving high ultimate composite strength because the PVA and the polypropylene could simultaneously contribute to the composite strength, and because of the synergistic interaction between the two reinforcing fibers.