Analytical model for predicting the compressive strength of recycled aggregate concrete

The use of recycled concrete aggregate obtained from construction and demolition waste is an effective way to reduce the negative environmental impact of construction and to preserve natural resources. However, concrete produced with recycled concrete aggregate (RCA) generally exhibits lower mechanical properties than conventional concrete made with natural aggregates due to the inferior characteristics of the recycled material. Most existing models for predicting the strength of recycled aggregate concrete (RAC) primarily consider the replacement ratio of natural aggregate, while the intrinsic properties of the recycled concrete aggregate (RCA) are not sufficiently accounted for. This paper proposes a simple analytical model for estimating the compressive strength of concrete with recycled concrete aggregate, which explicitly accounts for the replacement ratio, the strength of the original concrete ( f c , r = 40 MPa), and the water absorption of the recycled aggregate ( W r = 2 %). The proposed relationship has a dimensionless form, is based on physically justified parameters, and is intended for preliminary engineering estimations and parametric studies. The analytical and parametric analysis demonstrates that the obtained relationships are consistent with trends widely reported in the scientific literature.