Sustainable high strength polymer concrete with high ratios of recycled aggregate from different decades under heat curing

ABSTRACT This study investigates the influence of heat curing on polymer concrete (PC) incorporating high replacement ratios (up to 80%) of recycled aggregates sourced from demolished buildings of different ages to prepare recycle aggregate polymer concrete (RAPC). The research addresses the gap in understanding how recycled aggregate properties, influenced by the age of source structures, impact PC performance under varying curing conditions. Two curing methods were applied: (1) air curing for 28 days and (2) accelerated heat curing at 100°C for 2 hours, followed by air curing. Results show that heat curing significantly enhances compressive strength, reaching 69 MPa in reference specimens compared to 53 MPa under air curing. When using 10-year-old recycled aggregates, RAPC maintained comparable strength (up to 65 MPa at 60% replacement), while 20-year-old recycled aggregates led to lower strengths (51 MPa at 60% replacement). The key contribution of this study lies in demonstrating that heat curing can compensate for strength loss in RAPC, enabling high replacement ratios while maintaining mechanical performance, knowing that the optimal balance between strength retention and sustainability was achieved at 60% replacement. Also, these findings underscore the potential of promoting sustainability by reducing natural resource consumption and construction waste.