Influence of the Flexural Fatigue Properties of Recycled Aggregate Concrete Under Different Emery Replacement Ratios

Five groups of recycled aggregate concrete (RAC) mixtures with mass replacement ratios of emery (0, 5%, 10%, 15%, 20%) were prepared. The cubic compressive strength, splitting tensile strength, flexural strength, and flexural fatigue properties under stress levels of 0.6, 0.7, and 0.9 were tested. The fatigue reliability of RAC was analyzed based on the Miner model. Test results indicate that emery incorporation significantly improves the mechanical properties, flexural fatigue properties, and fatigue reliability of RAC. Compared with the reference group (0% emery), the 28-day cubic compressive strength, splitting tensile strength, and flexural strength of RAC with 20% emery increase by 18.62%, 27.35%, and 20.28%, respectively. The flexural fatigue life increases by up to 135.8% under high stress level (0.9). Flexural fatigue performance and fatigue reliability decrease with increasing stress level. The S-N curve was obtained based on the Wöhler mathematical model with high fitting reliability (R2 > 0.95).