Abstract: To investigate the influence of recycled coarse aggregate (RCA) substitution rates on the mechanical properties and discreteness of recycled coarse aggregate concrete (RAC), RAC specimens with three different substitution rates of 0%, 50%, and 100% were prepared for the quasi-static compressive test. In order to expand the limited test data, a large number of constitutive parameters were obtained by using the third-order moment inverse normal transform, and a nonhomogeneous mesoscale model that takes into account the variability of the mechanical properties of the RAC was established. The experimental and numerical results demonstrated that an increase in the RCA substitution rate led to a reduction in compressive strength and, in elastic modulus, and to a slight increase in peak strain of RAC. The discreteness of compressive strength, of peak strain and, of elastic modulus of RAC initially increased and subsequently decreased with the increase of RCA substitution rates, reaching the maximum at a substitution rate of 50%. With the experimental and numerical results, predictive formulas for compressive strength, peak strain, and elastic modulus of RAC at any reliability were proposed upon the Weibull distribution, offering a reference for the reasonable design of RAC components with different RCA substitution rates.