Study on Mechanical Properties and Mechanism of Recycled Brick Powder UHPC

Recycled brick powder (RBP) is a kind of solid waste material with pozzolanic activity, which can partially replace cement as cementitious to prepare concrete. In this paper, ultra-high-performance concrete (UHPC) was prepared by RBP. The effects different RBP contents mineral admixture on the mechanical properties and microstructure UHPC were studied experiments. results show that has certain weakening effect compressive strength development UHPC. decreases increase in replacement rate RBP, but 28 d each group specimens not less than 140 MPa. flexural toughness tensile strain increased first then decreased reached maximum at 40% 30%, respectively. exhibits good strain-hardening characteristics. addition, incorporation improve bond between steel fiber matrix ultimate reaches when substitution 40%. From perspective nano-scale characteristics, only fills pores micro-aggregate, also participates secondary hydration reaction further optimize pore structure