Abstract:The cube and prism specimens of gravel concrete with replacement ratio of recycled coarse aggregate r=0%, 30%, 50%, 70% and 100% were designed and manufactured. The change trend of cube compressive strength and prismatic compressive strength of concrete at different ages under different replacement rates of recycled coarse aggregate was studied. The results show that the compressive strength of concrete has no significant change when r is 30% when the age is 3 d and 7 d; If r is more than 30%, the compressive strength of concrete tends to decrease when r increases, and the decrease range is obvious. At the age of 14 d and 28 d, the compressive strength decreased with the increase of r. A calculation model for the correlation between cube compressive strength and prismatic compressive strength is proposed when the replacement ratio of recycled coarse aggregate is considered. The model is fc=(-0.190 3r2+0.148r+0.722 7)fcu.