Mechanical and Freeze-Thaw Durability Properties of Recycled Aggregate Concrete Made with Recycled Coarse Aggregate

Abstract

The influence of recycled coarse aggregates (RCAs) on the fresh, hardened, and freeze-thaw durability properties of recycled aggregate concrete (RAC) is investigated in the research reported in this paper. Four different mixes were considered with natural aggregate and three different replacement levels of RCA [i.e., (1) 30%, (2) 40%, and (3) 50%]. The fresh and hardened properties of RAC were investigated according to national standards where the target strength was 35 MPa in 56 days. The compressive strengths of different concrete mixes were determined after 3, 7, 28, 56, and 120 days of moist curing. The results are also presented in terms of stress-strain curves, modulus of elasticity, and Poisson’s ratio. Freeze-thaw durability performance of RAC was studied in accordance with a national standard. This paper shows that the performance of RAC slightly decreases with increasing RCA replacement levels; however, their overall performance is comparable to natural aggregate concrete (NAC). This paper indicates that the use of RCA in new concrete production can lead to a greener environment and pave the way for sustainable construction.