Effect of recycled concrete coarse aggregate from multiple sources on the hardened properties of concrete with equivalent compressive strength

This study evaluated the effect of fully replacing natural aggregate (NA) with several sources of recycled concrete aggregate (RCA) on the various mechanical properties of multiple concrete mixtures having equivalent compressive strength and slump (compressive strengths between 40 and 60 MPa and slumps between 75 and 125 mm). The RCA concrete (having equivalent compressive strengths as the NA concrete) had modulus of elasticity values up to 19% lower than NA concrete. The average secant modulus of elasticity of bulk RCA was evaluated and was shown to be proportional to the modulus of elasticity of concrete incorporating the RCA as coarse aggregate. Fracture energy of RCA concrete was measured using single edge notched double-cantilevered (SENDC) beam specimens and was measured to be up to 32% lower in comparison to the NA concrete specimens. Fracture energy of RCA concrete was found to increase with an increase in aggregate strength.