Effect of Loading and Beam Sizes on the Structural Behaviors of Reinforced Concrete Beams Under and After Fire

Performance-based fire resistance design needs consideration of various influencing parameters of structures such as load levels and cross-sectional size. Therefore, the studies of fire damaged reinforced concrete (RC) structures are performed experimentally and analytically. Twelve RC beams with different load levels and cross sections are exposed to high temperatures following the ISO 834 standard time temperature. After the fire test, the fire-damaged beams are loaded using four-point loading to obtain its residual strength. In addition, ABAQUS 6.10-3 is used to preform structural analyses of the ductility of the fire-damaged beams. The results indicate that the temperature, stiffness and ductility of the fire-damaged beams are significantly influenced by the load level, cross-sectional size and time exposed to fire. Also, the ductility of the fire-damaged beam can be predicted using an analytical method, which is not easy to otherwise determine experimentally.