Bonding behaviour between steel fibre and concrete matrix after experiencing elevated temperature at various loading rates

Abstract

The bonding behaviour between steel fibre and concrete matrix at elevated temperature and various loading rates was investigated. Pullout tests were carried out on the hooked-end steel fibre reinforced concrete specimen and the effects of elevated temperatures (200, 400, and 600°C) and loading rates (2, 10, and 50 mm·min−1) were considered. The ultimate bond strength and energy absorption were discussed to evaluate the bonding behaviour. The results revealed that the bonding behaviour for the case of 400°C performed best, while the bonding behaviour for the case of 600°C performed the worst. At room temperature, the bonding behaviour is similar to the case of 200°C. In addition, the higher the loading rate, the greater the fluctuation of the bond slip curve of the specimen, and higher ultimate pullout load and energy absorption may be observed.

Keywords

• hooked-end steel fibre
• concrete mortar matrix
• bonding behaviour
• pullout rate
• elevated temperature