Utilization of ceramic waste powder in cement mortar exposed to elevated temperature

The utilization of ceramic waste powder (CWP) is increasing in construction industry and influences significantly fresh and mechanical properties of concrete. However, these properties of concrete significantly changed if subjected to higher temperature. Thus, this paper presents the effect of partial replacement of cement to CWP with different weight percent (0%, 20%, 40% and 60%) on the workability, dry density and compressive strength of the concrete. In addition, the influence of elevated temperature (200–800 °C) at 2 h was also carried to investigate the effect on residual compressive strength of the concrete. Furthermore, ANOVA analysis was used for the prediction and optimization of the influenced variables on the compressive strength (response) of the concrete mixes. The results showed that the CWP and temperature significantly influenced the workability, dry density and compressive strength of the concrete mixes. And increasing the percentages of CWP leads to a reduction in the workability, dry density and compressive strength of the concrete mixes. The highest values of workability, dry density and compressive strength were obtained as 240 mm and 220 mm, 2200 kg/m3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{m}}^{3}$$\end{document} and 2215 kg/m3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{m}}^{3}$$\end{document} and 30 MPa and 33 MPa for A-20 and B-20 mixes, respectively, whereas increasing the temperature caused to decrease the compressive strength of the concrete, and in this context, the maximum residual compressive strength was observed as 32 MPa and 36 MPa for A-20 and B-20, respectively, at 200 °C. Furthermore, CW-A and temperature significantly impact the compressive strength of the concrete, whereas CW-B not. For the optimization, 22% of CW-A, 31.5% of CW-B and 122 °C provide the optimum compressive strength of the concrete. These results give a good indication that CWP could be used in the production of eco-friendly concrete with improved mechanical properties.