Impact resistance of engineered geopolymer composite (EGC) in cold temperatures

This paper was intended to investigate the impact resistance of engineered geopolymer composite (EGC) in cold temperatures. The ambient cured EGC based on local PVA fibers, which has favorable environmental and eco-nomic benefits, was first developed and tested under uniaxial compressive and tensile loading conditions. The drooping hammer test machine retrofitted with a liquid nitrogen canister was applied to conduct the impact tests of EGC specimens under different cold temperatures, i.e.,-10 degrees C,-20 degrees C and-50 degrees C. The conventional engi-neered cementitious composite (ECC) specimens and the corresponding cement mortar were also tested as the control groups. The influences of alkali concentrations on the compressive, tensile and impact behaviors of EGC were investigated. According to the experimental results, it was found that the developed EGC could have comparable compressive strength and tensile behaviors with ECC. For both EGC, ECC and their corresponding matrixes, the impact load increased while the ultimate displacement decreased when the temperature dropped from-10 degrees C to-50 degrees C. It was also found that the energy dissipation coefficient of EGC specimens increased with the decrease of temperature, indicating that EGC materials have preferable impact resistance under low or ultra -low temperature environments.