Effects of high-temperature exposure on concrete containing waste porcelain coarse aggregates and steel chips

Abstract

The objective of this study is to find a new way for improving the heat resistance of concrete at extreme temperatures in structural members at low cost. In this study, a new generation of ceramics or porcelains were used in concrete for the first time. These ceramics have higher strength and heat resistance than all other types of tiles. They were used in concrete as 25% on up to 100% replacements for coarse aggregates, as well as with two types of cement (Portland cement Type I and alumina cement). Red ceramics were also used in some specimens for better comparison between heat resistance of porcelains and ordinary ceramics. Moreover, waste steel chips were used at 1%, 1.25%, and 1.5% volume ratios. The specimens were exposed to temperatures of 100 °C–850 °C, and then their compressive strength, weight change, and long-term behavior were determined. In addition, fractal dimensional changes were also determined to study concrete's crack propagation; it was observed that it decreased to zero in concrete containing Portland cement and waste porcelains after exposure to 600 °C. Conventional concrete made of alumina cement exhibited a reduction of 92% in compressive strength after exposure to 850 °C, while steel chip-concrete and porcelain-concrete showed reductions of 82% and 74%, respectively. Results also indicated that specimens with Portland cement have better heat resistance than alumina cement up to 600 °C, although such specimens were not able to withstand heat above 600 °C.