Abstract: The application of recycled coarse aggregate in the field of concrete production effectively reduces environmental pollution, and realizes building waste recycling. However, due to the inherent defects such as surface wrapping by existing mortar and initial imperfection, recycled coarse aggregate concrete (RCAC) has a relatively high water absorption rate and inferior interface bond which will lead to poor frost resistance of RCAC structures exposed to subzero environment. Based on the review of both domestic and overseas researches for frost resistance of RCAC, it is found that the interfacial transition zone in freezing RCAC presents complexly vulnerable character. The development of micro-crack and pores causes the deterioration of RCAC under the freeze-thaw cycles. The growth of recycled coarse aggregate replacement percentage accelerates the degradation of frost resistance, and the mass content of recycled coarse aggregate should be controlled within 50% for optimum consideration. Mass loss, relative dynamic elastic modulus and compressive strength are usual parameters for damage level evaluation of recycled concrete. The mass loss shows negative growth at the initial stage of test, and the relative dynamic elastic modulus is less sensitive under limited freeze-thaw cycles. By contrast, the compressive strength better reflects the freeze-thaw damage level of RCAC. In the future, it is necessary to pay more attention on more systematic and in-depth research into the freeze-thaw damage mechanism of recycled concrete, and to explore reasonable non-destructive test indices that work well, as well as specific evaluation of the frost resistance behavior of recycled concrete for specific engineering environments based on standard freeze-thaw tests, in order to promote more widespread use of RCAC.

Key words: recycled coarse aggregate concrete, frost resistance property, replacement percentage, failure mechanism, microstructure, mass loss, relative dynamic elastic modulus, compressive strength