Evaluation of high-strength concrete made with recycled aggregate under effect of well water

Abstract

In the present study, the influence of using recycled coarse aggregate (RCA) and well water (WW) on the mechanical characteristics of high-strength concrete were investigated. The reuse of devastated structures as recycled aggregate became an especially serious issue in Mosul City, Iraq, following the 2017 war. These events have also made it difficult to access drinking water. This study sought to determine the effect of the more readily available well water in Mosul City when combined with recycled aggregate on compressive, splitting, and flexural strengths of high-strength concrete. The mixtures were prepared using four different percentages of RCA, replacing 0 %, 25 %, 50 %, and 100 % natural coarse aggregate (NCA). In total, eight mixtures were designed, four mixtures cured by potable water (PW), and the other four mixtures cured by well water. The results showed the compressive strength decreases by about 16.0 % when using well water for concrete made with NCA. Also using WW caused drop about 13.2 %, 10.0 % and 8.5 % for concrete containing 25 %, 50 % and 100 % RCA, respectively. The flexural and splitting tensile strength also reduced when using well water. A regression analysis allowed the formulation of new material constitutive relationships for high-strength concrete, including the effects of WW and RCA.