Residual Strength of Fiber-reinforced EPS Lightweight Concrete After Exposure to Fire

Aggregates typically constitute 65%-75% of the concrete volume and significantly influence its mechanical properties while also playing a crucial role in the post-fire behavior. This study explores the effect of fire exposure on thermal conductivity, residual strength, and performance of Expanded Polystyrene (EPS) lightweight Self-Compacting Concrete (SCC) reinforced with steel fibers. EPS beads are utilized as a coarse aggregate replacement and steel fiber reinforcement with different volume fractions. The test for the pre-fire concrete samples indicated that EPS beads significantly reduced the mechanical properties of the hardened concrete, resulting in significant improvement in the splitting and flexural strength due to the steel fiber reinforcement. Also, the rheological properties for the mixtures were within the ENFARC limits for the different EPS and fiber volume fractions. Following exposure to fire, the findings revealed that increasing the EPS content enhances the retention of strength in the post-fire samples. The experimental results highlighted the constructive effect of EPS beads on tensile strength, flexural strength, and mass loss due to fire exposure. On the other hand, for post-fire performance, results revealed a significant adverse effect of the steel fibers on the thermal conductivity and mechanical properties of the concrete samples.