Comparative study on properties of recycled concrete mixed with slag and polypropylene fiber/steel fiber

Abstract

In order to study the effect of fiber and slag on the performance of high performance recycled aggregate concrete, polypropylene fiber/steel fiber and slag are selected as admixtures, in which fiber is used as admixture and slag is equivalent to replace cement content. The influence of recycled aggregate content, admixture formula and admixture on the mechanical and water absorption properties of high performance recycled concrete and its improvement effect were analyzed systematically. The results showed that when the slag is added, the early mechanical properties of concrete have little effect, the later is slightly improved, but the water absorption of concrete is improved significantly. Adding fiber can not only improve the compressive strength, splitting tensile strength and flexural tensile strength of high performance recycled concrete, but also significantly improve the water absorption properties. Fiber and slag composite modified material can bond concrete mixture into a whole and improve the density of the mixture.