Mechanical properties of hybrid fibers engineered cementitious composites containing ceramic wastes exposed to elevated temperatures

This study investigated the compressive and tensile performance of hybrid fibers reinforced engineered cementitious composites (ECC) containing ceramic wastes after and under elevated temperatures, respectively. Four temperatures of 20, 200, 400, and 600 ℃ were employed. The effects of ceramic polishing powder, ceramic sand and basalt fibers on the mechanical properties of hybrid fibers reinforced ECC were examined. The residual compressive strength and elastic modulus declined continuously in polyethylene (PE)-ECC as the temperature rose, while increased slightly in hybrid fibers reinforced ECC after 200 ℃. The tensile strength and ultimate tensile strain of both ECCs deteriorated sharply when the temperature exceeded 200 ℃. Tensile failure modes changed from multiple cracking to single one. Replacement of fly ash by ceramic polishing powder resulted in variations of 9.3 %, 21.3 %, −18.1 % and −24.6 % in compressive strength of ECC at 20 and after 200, 400 and 600 ℃, respectively. Replacement of quartz sand by ceramic sand resulted in reductions of 8.6 %, 21.7 %, 58.0 % and 67.3 % in compressive strength of ECC at 20 and after 200, 400 and 600 ℃, respectively. Basalt fibers could improve the tensile strength of ECC by 16.6 %, 20.6 % and 56.3 % at 200, 400 and 600 ℃, respectively.