Experimental Evaluation of Energy Absorption and Post-Failure Behaviour of Steel Fibre-Reinforced Concrete

Abstract

Steel fibre-reinforced concrete (SFRC) is a composite cementitious material in which discrete steel fibres are uniformly distributed throughout the concrete matrix to improve crack resistance, ductility, toughness, and post-cracking load-carrying capacity. Conventional concrete exhibits relatively brittle behaviour because of its low tensile strength and limited ability to sustain load after cracking. This study experimentally evaluates the energy absorption capacity and post-failure behaviour of SFRC under flexural loading. Four fibre-volume fractions, namely 0%, 0.5%, 1.0%, and 1.5%, are considered using hooked-end steel fibres. Beam specimens are subjected to third-point flexural loading, and load-deflection responses are recorded to determine first-crack load, peak load, residual strength, flexural toughness, and energy absorption capacity. Particular emphasis is placed on post-failure behaviour, including crack propagation, fibre bridging, crack opening, failure characteristics, and residual load-carrying capacity. The results indicate that increasing steel-fibre content substantially improves post-cracking performance and energy absorption. The 1.5% fibre mixture demonstrates the highest expected toughness, residual strength, and deformation capacity compared with conventional concrete. These improvements are mainly attributed to fibre bridging, mechanical anchorage, fibre pull-out resistance, and controlled crack propagation. The study highlights that energy absorption and post-failure behaviour are critical parameters for assessing SFRC performance in structural applications subjected to impact, cyclic, seismic, and other severe loading conditions.