Effects of ring-type and straight steel fibres on the compressive performance of rubber-recycled aggregate concrete

Abstract

The application of rubber-recycled aggregate concrete (RRAC) is beneficial for the deep integration of environmental protection and circular economy. However, the mechanical properties of RRAC are poor. The use of ring-type steel fibres (RSFs) and straight steel fibres (SSFs) may be a potential method to solve this problem. This study investigated the single and combined effects of RSFs and SSFs on the compressive performance of RRAC. It is found that compared with the single use of RSFs or SSFs, the combined use of RSFs and SSFs better improved the compressive performance of RRAC. The combination of RSFs and SSFs maximally increased the compressive strength, strain at peak stress, and toughness of RRAC by 16.46%, 14.63%, and 40.09%, respectively. The optimal contents of RSFs and SSFs were 0.4% and 0.8%, respectively. Finally, the effects of RSFs and SSFs on the damage evolution curves of RRAC were analysed.