This study investigates the post-fire flexural performance of reinforced concrete (RC) slabs, with novelty in evaluating the combined effects of reinforcement type, hybrid fibre concretes, and thermal exposure at 700°C for two hours. An experimental program was conducted on eight one-way simply supported slabs (2,200 mm long) tested under two-point loading. Key variables included reinforcement type (steel vs. stainless steel), mix composition (ordinary Portland cement, 1% steel fibre concrete, or a combination of 2% plastic wire and 1% steel fibre concrete), and thermal exposure (heated vs. unheated). Experimental results were compared with finite element simulations in ABAQUS and predictions from ACI 318-19.
The results showed that plain stainless-steel reinforcement experienced severe bond deterioration, reducing load capacity by 67.3% and initial stiffness by 71% relative to conventional steel …