Performance of steel-fibre-reinforced self-compacting concrete subjected to high temperature

Self-compacting concrete (SCC) has recently become more popular in high-rise structures and industrial units. Such structures are more at risk of fire owing to the extensive installation of gas and electrical appliances, so investigating the performance of SCC after high-temperature exposure is extremely important. Therefore, in this study, the properties of SCC after exposure a temperature of 500°C were investigated. Furthermore, differential expansion between aggregates and the cementitious matrix can induce internal stresses, which may result in cracking. Therefore, steel fibre (SF) at different dosages were added to SCC to prevent crack formation under high temperatures. Marble waste (10%) was examined as a filler material, and was found to improve the interfacial transition zone. The performance of SCC after high-temperature exposure was evaluated through visual inspection (cracking and spalling) and assessments of mass loss, compressive strength and tensile strength. Furthermore, the microstructure of the SCC was analysed using scanning electron microscopy. The results indicated that the addition of SF improved the performance of SCC at elevated temperatures. Considerable degradation was observed in the control mix (without SF) at 500°C. However, the SF-reinforced SCC was stable and had better strength at 500°C. Therefore, it is recommended that SF-reinforced SCC exposed to temperatures up to 500°C without any harmful impact.