A Finite Element Modeling (FEM) Approach in Evaluating Fire-Induced Damage in Reinforced Concrete Slabs

The study proposes a finite element modeling (FEM) method for analyzing fire-induced damage in reinforced concrete (RC) slabs using ANSYS Workbench. RC slabs experience severe damage in terms of thermal and mechanical degradation under fire exposure, including microcracking, loss of stiffness, and compressive strength weakening. To fill the gaps in the literature on post-fire one-way reinforced concrete slabs, a three-dimensional FEM model was developed using ANSYS software, incorporating Eurocode 2 properties of temperature-dependent concrete strength and steel strength. A Coupled Field analysis was performed using ISO 834 standard fire exposures from 200℃ up to 1200℃ and exposure durations of 30 minutes to 180 minutes. Validation against published experimental data indicated that there was a close correlation between simulated and experimental results, with the highest deflection difference of 1.484 mm. It was also found that temperature gradients resulted in significant mid-span deflections, tensile cracking, and progressive stiffness deterioration. Regression analysis showed that temperature and exposure time influence the loss of concrete strength, and exposure time is more effective.