Performance and microscopic study of various mineral admixtures on reactive powder concrete

Abstract

A ternary admixture system of industrial waste (silica fume (SF), slag powder (SL), and fly ash (FA)) was used to replace quartz powder and reduce the cement content to prepare green, low-carbon and high-performance cement-based materials. The mechanical properties of RPC under natural watering curing (NWC), standard curing (TC), and mixed curing (MC) conditions were studied, and the influencing mechanism was analyzed and explored from a microscopic perspective. The results show that the MC curing system promotes the early hydration of cement and improves the compactness of the matrix. However, the strength in the later stage was affected by temperature internal force, and the compressive and splitting tensile strength in the later stage increased by −0.1% and −36.27%, respectively. The 28 day compressive strength of RPC under TC and NSC conditions increased by 10.30% and 11.78% compared to 7 days, while the splitting tensile strength increased by 17.42% and 14.10%, and the difference between RPC and MC strength gradually decreased.