Influence of Mineral Additions on the Anti-cracking Performance of Recycled Aggregate Concrete

摘要

The effect of fly ash (FA) and slag (SG) on the anti-cracking performance of recycled aggregate concrete (RAC) is discussed, taking the toughness index as the concrete anti-cracking performance evaluation index, and the mechanism of action is researched at the meantime. The experimental results show that the strength of RAC is reduced when containing fly ash only or slag only, but the crack-resistance of RAC is improved significantly at 3 days and 28 days of hydration process of RAC. Furthermore, the 28 days anti-cracking performance of RCA improved significantly with 30% FA single-doped or 20% SG single-doped. It can improve the 28 days anti-cracking performance of RAC, by using double-mixture of fly ash and slag, there is an optimal FA/SG ratio and a best total content, the FA/SG ratio is 3:1 and the total content is 30%.