Abstract
In this research, the effects of recycled coarse aggregate (RCA) gradation (5–10 mm, 5–16 mm, 5–20 mm, and 5–31.5 mm), RCA content (30 %, 50 %, and 70 %), fly ash content (10 %, 20 %, and 30%) and water–binder ratio (0.35, 0.4, and 0.45) on the stress–strain constitutive relationship of recycled aggregate concrete (RAC) were analyzed. For this purpose, 45 prism specimens were designed, and then it was obtained by gray relational entropy analysis that the water–binder ratio and RCA content have a considerable influence on RAC’s mechanical and energy absorption properties. A mathematical expression for the stress–strain constitutive relationship of the RAC concerning the four aforementioned factors was developed through experimental investigation and regression analysis. The proposed model is compared with the experimental date, and the result has a good fit.