Physical and Mechanical Characteristics of Cement Mortar with Coal Bottom Ash as Fine Aggregate Under Elevated Temperature

Abstract

AbstractThis experimental study aims at evaluating the performance of coal bottom ash (CBA) mortar after exposure to elevated temperatures. Two mortar mixes were prepared in which one was conventional natural sand (NS) based mortar and other mix contains CBA as 100% replacement of NS. The test specimens were cured for 28 days at ambient condition and then was heat treated at different elevated temperature (200, 400, 600 and 800 °C) using an electric controlled high-temperature furnace. The effect of elevated temperature on the mass loss, ultrasonic pulse velocity (UPV) and compressive strength of mortar specimens was evaluated after the high-temperature treatment. In addition, empirical equation derived from regression analysis was proposed to predict the residual mechanical strength of mortar incorporating CBA as fine aggregate at different elevated temperature. The test results signify that both mass and UPV decreases with increases in temperature, however, residual compressive strength of CBA mortar was better or comparable to NS mortar up to 400 °C, but above 400 °C; strength reduction rate in CBA mortar was higher than NS mortar.KeywordsCoal bottom ashFine aggregateElevated temperatureMortarCompressive strengthMass lossUPV