Bond performance of recycled coarse aggregate concrete with rebar under freeze-thaw environment: A review

In this article, a review focusing on the frost resistance of recycled coarse aggregate concrete (RAC) and the bond performance of RAC with rebar under freeze-thaw environment is carried out. The results show that there are still some controversies about the advantages and disadvantages of the frost resistance of RAC, and many influencing factors have not been considered. The mass of the RAC pullout specimens shows a trend of first increasing and then decreasing after freeze-thaw cycles. The failure modes of the RAC pullout specimens after freeze-thaw cycles include pullout failure, pullout-splitting failure, splitting failure, and rebar yielding failure. The bond performance of RAC with rebar shows a degradation trend after freeze-thaw cycles, mainly in the decrease in bond strength and the increase in bond slip. The bond performance of RAC specimens is inferior to that of natural aggregate concrete specimens after freeze-thaw cycles. The bond strength prediction models and the bond-slip constitutive relation prediction models of RAC with rebar after freeze-thaw cycles have been summarized to ensure that engineers can better understand their applicability. The bond stress distribution between the RAC and rebar in the anchoring area is not uniform and constantly changes with the number of freeze-thaw cycles. The degradation mechanism of the bond performance of RAC with rebar after freeze-thaw cycles is analyzed.