LAUSR

Abstract Except for service loadings, concrete or steel fiber reinforced concrete (SFRC) may be subjected to some extreme loadings, such as fire, impact, blast or their combinations during occasional events. In order to capture the mechanical behavior of SFRC subjected to both high temperature and high strain rate, three SFRC mixtures with different steel fiber volume fractions were experimentally tested using both resistance furnace and SHPB apparatus. The exposure temperatures included 25 °C, 200 °C, 400 °C, 600 °C and 800 °C, while the strain rate range was from 36 s−1 to 185 s−1. For the comparison purpose, quasi-static tests were carried out at corresponding temperatures. The results indicate that under temperatures no higher than 600 °C, the addition of steel fiber can effectively inhibit SFRC specimens from crushing into fragments when subjected to dynamic compressive loadings. Both quasi-static and dynamic stress-strain curves have similar shapes, and they become flatter and flatter with respect to temperature. Under elevated temperatures, dynamic compressive strength of SFRC still displays obvious strain rate sensitivity. The exposure to high temperature reduces strength and elastic modulus of SFRC while increases its critical strain. Peak toughness increases firstly and then decreases with increasing the temperature. The amount of steel fiber has a quite slight effect on strength, critical strain, elastic modulus and toughness of SFRC in high temperature conditions.