Concrete structural members in high-temperature industrial environments are susceptible to thermal cracking and performance degradation. This study aims to evaluate the thermo-mechanical behavior and reliability of glass fiber–reinforced concrete (GFRC) beams exposed to elevated temperatures using finite element-based probabilistic assessment.
RC beams incorporating glass fibers at volume fractions of 0.5%, 1.0%, 1.5% and 2.0% were numerically investigated under thermal exposure levels ranging from 25°C to 600°C. A total of 20 beam models were developed in ABAQUS using cohesive zone modeling (CZM) to simulate crack initiation and propagation. Several structural responses were evaluated and probabilistic analysis was conducted to estimate failure probability under thermal loading conditions.
Results indicate that incorporation of 1.5% glass fiber provides the optimum structural response. Compared with conventional RC beams, GFRC beams exhibited an increase of approximately 30–35% in load capacity at crack initiation and a 20–28% increase in mid-span deflection capacity at ambient temperature. Fracture energy increased from 0.10 N/mm in control beams to approximately 0.22 N/mm in fiber-reinforced beams, resulting in a reduction in crack width from 0.102 mm to 0.051 mm. The reliability index increased from β = 1.9 for control beams to β = 2.6 for beams containing 1.5% fibers, while the probability of failure decreased from 18% to 6% after thermal exposure.
This study provides a comprehensive numerical framework integrating CZM and reliability-based analysis to assess the high-temperature performance of GFRC beams, offering valuable insights for fire-resistant structural design in industrial applications.
