Bond behavior between steel reinforcement and concrete with recycled fine aggregate under different confinement levels

Journal article, 2026

This paper identifies the trends on the bond behavior of concrete with recycled fine aggregate (RFA). This was analyzed replacing natural fine aggregate with recycled fine aggregate at different percentages (20%, 50% and 100%). Using a real-case fine recycled aggregate from a decommissioned bridge and keeping constant the mix proportion, the w/c ratio. The bond strength was measured in three different confinement levels with 16 mm rebars, and the bond was confirmed to be reduced compared with conventional concrete. The results indicate a reduction trend of the bond strength as the proportion of recycled fine aggregate increases for the and both in splitting and pull-out failure modes. Finally, when using the Model Code 2020 to predict bond strength, the ratio of experimental values to theoretical predictions may decrease by up to 40%, therefore, to maintain design conservatism, the anchorage length should be increased in this case.