Tensile strain-hardening behavior of polyvinyl alcohol engineered cementitious composite (PVA-ECC)

A high-performance polyvinyl alcohol fiber-reinforced engineered cementitio us composite (PVA-ECC) for structural applications has been developed under the performance-driven design approach. Fiber, matrix, and fiber/matrix in terfacial properties were tailored based on micromechanics models to satisf y the pseudo strain-hardening condition. In this paper, the effects of fibe r surface treatment and sand content on the composite performance were expe rimentally investigated. Results from uniaxial tensile tests show an ultima te strain exceeding 4%, as well as an ultimate strength of 4.5 MPa for the composites, with a moderate fiber volume fraction of 2.0%. The specimens re veal saturated multiple cracking with crack width at ultimate strain limite d to below 100 mum. The underlying reason of the distinctly different tensi le behavior between normal fiber-reinforced concrete and PVA-ECC is highlig hted by the comparison of complementary energy from their fiber bridging st ress and crack opening curves.