Post-fire impact behaviour of rubberized alkali-activated slag concrete

Abstract

Rubberized concrete is eco-friendly concrete with improved impact resistance. However, impact loads may also be combined with fire due to blasting, explosions, and earthquake. Hence, this study investigates the post-fire impact behaviour for rubberized alkali-activated slag (AAS) concrete. Static and dynamic properties of AAS mixtures, incorporating 5%, 10%, and 15% crumb rubber, were evaluated under ambient and after exposure to elevated temperatures (200, 400, and 600 °C). Results reveal that AAS properties' degradations were similar to ordinary Portland cement (OPC) at ambient temperature. At elevated temperatures, the differences in hydration products’ nature between AAS and OPC alternated the performance. The formed low Ca/Si ratio calcium silicate hydrated in the AAS exhibited higher stability at elevated temperatures. AAS with 10% rubber content showed an optimum impact performance. Above 400 °C, degradation of the binder microstructure and voids due to rubber particle decomposition adversely affected the impact performance of AAS. The addition of 0.5% steel tire wire showed a high potential sustainable solution to maintain adequate performance.