Post-fire reliability analysis of concrete beams retrofitted with CFRPs: a new approach

A new reliability analysis approach for the flexural capacity of post-fire reinforced concrete (RC) beams retrofitted with carbon-fibre-reinforced polymers/plastics (CFRPs) is proposed. In this approach, the thermal parameters of RC beams are first determined to enable heat transfer analysis in Abaqus. Based on the thermal response obtained from the heat transfer analysis, a section method is used to calculate the post-fire residual flexural capacity of RC beams. Reliability analysis of the beams retrofitted with CFRPs is subsequently performed using the Monte Carlo method. The effects of fire exposure time, concrete cover thickness and CFRP usage on the reliability of the flexural capacity of RC beams after fire exposure were studied. This new approach was found to be accurate and effective. It provides an effective reliable model for the evaluation of the mechanical properties of post-fire RC beams strengthened with CFRPs.