The effect of high temperature on the residual mechanical performance of concrete made with recycled ceramic coarse aggregates

Abstract

SummaryThis paper presents an experimental study on the residual mechanical properties of concrete with recycled ceramic coarse aggregate (RCCA) after exposure to elevated temperatures. Four concrete mixes were produced: a control concrete and three concrete mixes with replacement ratios of 20, 50 and 100% of natural aggregate (NA) by RCCA. The specimens were subjected to temperatures of 200, 400 and 600°C, for a period of 60 min. After cooling down to room temperature, the following concrete properties were evaluated: (i) compressive strength; (ii) splitting tensile strength; (iii) modulus of elasticity; (iv) ultrasonic pulse velocity (UPV); and (v) water absorption by immersion. At ambient temperature, as expected, the replacement of NA by RCCA resulted in a performance reduction of concrete. After exposure to elevated temperature, in general, the results obtained indicated an improvement of the residual relative mechanical properties of the mixes with RCCA, particularly after exposure to 400 and 600°C. However, exposure to the highest temperature (600°C) tended to cause spalling in concrete mixes containing RCCA. Significant linear correlations were observed between the residual compressive strength of all concrete mixes and both the UPV and the water absorption by immersion. Copyright © 2014 John Wiley & Sons, Ltd.