Abstract:At present, the PVA (polyvinyl plcohol) fiber used in ECC (engineered cementitious composites) mainly produced by KURARAY Co. Ltd., Japan, and its cost is very high. The price of domestic PVA fiber is reasonable, however, the tensile ductility of the domestic PVA ECC is limited. To further increase the tensile ductility of ECC, looking after both side the cost, domestic PVA fiber was mixed with Japanese one at a proper proportion to develop hybrid PVA ECC. Based upon the micromechanics model, the mix proportion was redesigned through the parametric analysis. The four point bending test, uniaxial tensile test and uniaxial compressive test were carried out to characterize the mechanical behavior of hybrid PVAECC with five mix proportions. According to the performance and cost of the material , three typical mixes were proposed: M7 with low cost, relatively low tensile ductility and reinforced by domestic PVA fiber, M17 with moderate cost, relatively high tensile ductility and reinforced by hybrid PVA fiber and M21 with high cost, high tensile ductility and reinforced by Japanese PVA fiber. In practical applications which mix to be chosen depends on the structural performance to be achieved. The development of hybrid ECC helps cut costs of ECC, and the widespread use of ECC becomes possible.
