TY  - EJOU
AU  - Liu, Hongyan 
AU  - Wang, Fang 
AU  - Zhao, Jie 
AU  - Wu, Feng 

TI  - Thermo-Mechanical Behavior and Residual Strength of Reinforced Concrete Beams under Fire Exposure
T2  - Structural Durability \& Health Monitoring

PY  - 
VL  - 
IS  - 
SN  - 1930-2991

AB  - This study investigates the thermo-mechanical behavior and residual strength of full-scale reinforced concrete (RC) beams subjected to ISO-834 fire exposure, emphasizing temperature-dependent material degradation and bond-slip effects. A sequentially coupled numerical framework was developed in ABAQUS, integrating a temperature-indexed Concrete Damage Plasticity (CDP) model for concrete, elastoplastic steel constitutive laws, and a temperature-dependent bond-slip model implemented via nonlinear SPRING2 elements. The model explicitly accounts for post-peak concrete softening, steel yield degradation, and interface deterioration, and was calibrated against full-scale experiments. Experimental measurements included internal and surface temperatures, load–midspan deflection, and residual strength after natural cooling. The numerical results closely reproduce the experimental observations, with deviations of 7%–10% for both mid-span deflection and ultimate load. Key findings include: C40 concrete retains ~60% of its ambient compressive strength at 300°C–400°C; stiffness and peak load decrease by 30%–70% and 40%–50% at 600°C, respectively; residual load capacity drops to 20%–25% at 700°C. Steel yield strength decreases by ~50% at 600°C, and bond deterioration accelerates deflection and reduces residual capacity. This integrated numerical–experimental framework provides a validated predictive tool for post-fire performance assessment of RC beams, supporting fire-resilient design and structural safety evaluation.
KW  - Thermo-mechanical coupling; reinforced concrete; fire resistance; concrete damage plasticity (CDP); bond-slip; residual strength

DO  - 10.32604/sdhm.2026.079457