The influence of carbonized recycled fine aggregate on the bond properties between recycled aggregate concrete and corroded rebars

Abstract

Recycled aggregate concrete (RAC) technology is one of the important measures for the development of green concrete, which can realize the sustainable development of architecture, resources and environment. Steel corrosion has great influence on the safety and durability of reinforced concrete structure, the research problem of bonding between corroded steel bars and RAC has important significance and engineering value. The effect of carbonized recycled fine aggregate (C-RFA) on bond behaviour between corroded rebars and RAC was studied through 28 sets of pull-out tests, were performed on RAC with recycled coarse aggregate (RCA) replacement percentage of 70%. Four carbonized recycled fine aggregate replacement percentages (0%, 20%, 30% and 40%) and four corrosion rates (0%, 1%, 2% and 4%) were considered in this study. The results show that carbonized RFA improved the peak pull-out strength of the specimens. The peak pull-out strength of the specimens with 20% C-RFA replacement percentage had only 1.02% decrease compared with those of unincorporated of RFA. When rebar corrosion rates was less than 4%, the corrosion of rebar improved peak pull-out strength of the specimen. It was found that 2% corrosion rate had the most significant effect.