Influence of recycled coarse aggregate replacement percentage on fatigue performance of recycled aggregate concrete

The fatigue residual strength or stiffness of concrete refers to its strength or stiffness after a certain extent of fatigue loading. They decrease with loading cycles, a distinct feature of the fatigue process. To investigate the influence of recycled coarse aggregate (RCA) content on the fatigue performance of recycled aggregate concrete (RAC), an experiment about compressive fatigue residual strength on RAC with different replacement percentages was conducted. The results show that fatigue life, residual strength, and residual stiffness all decrease with an increase in RCA replacement percentage, with the smallest effect on stiffness. The residual strength and stiffness degradation curves of RAC were obtained by regression analysis and the replacement percentage effect on degradation laws was discussed. Furthermore, fatigue damage evolution was analyzed by defining the damage variable based on residual strength.