Effects of environmental temperature on the mechanical properties of polyethylene fiber-engineered cementitious composites

Engineered cementitious composites (ECC) incorporated with synthetic fibers possess extraordinary tensile capacity; however, temperature sensitivity of synthetic fiber arouses concern about the reliability of ECC working at extremely environmental temperature. This article is aimed to study the influence of environmental temperatures, from -20 to 90 degrees C, on the mechanical properties of polyethylene (PE) fiber reinforced ECC (PE-ECC). Experiments were conducted from four different angles, that is, compressive, and tensile properties of composites, fiber bridging behavior of composites, fracture toughness of cementitious matrix, and tensile property of PE fiber bundle. It is demonstrated that temperatures have significant impacts on the tensile and compressive strength of PE-ECC. Furthermore, the test results indicated that the tensile strength of PE fiber, fracture toughness of matrix and fiber bridging strength all decreased, while the elongation of fiber and crack opening displacement are increased with temperature increasing from -20 to 90 degrees C. On this basis, a pseudo-strain-hardening index is utilized to explain the mechanism underlying the temperature-dependent behaviors of PE-ECC.