Evaluation of mechanical properties and leaching tests results of mortars containing waste bottom ash as replacement of cement

Abstract

The disposal of waste bottom ash (WBA) is an environmental and economic challenge for the manufacturer. Therefore, disposal of waste bottom ashes is important for sustainable production. In this study, the usability of WBA instead of cement in the mortar was investigated. For this purpose, the workability, ultrasonic pulse velocity (UPV), flexural strength (f_f), compressive strength (f_c), microstructure, and hazard potentials of mortars containing WBA were examined. Effect levels of the selected variables (replacement ratio: 0%, 5%, 10%, 15%, 25%, 35%, and 50%, specimen age: 28, 60, and 90 day) on the UPV, f_f, and f_c were determined by ANOVA, and response surfaces were created. UPV and f_c were decreased at all specimen ages with an increasing replacement ratio. The R² of the models for the UPV, f_f, and f_c is higher (0.9660, 0.8034, and 0.9029). According to the leaching test results, Cd, Pb, Hg, and As values of all mortar samples were below the detection limit (not detectable) in this evaluation. The Cr values in all mortar samples remained below the maximum concentration of 5 mg/L, which is the given restriction of TCLP procedure.