Simplified Temperature Prediction Method for Insulated CFRP-Strengthened RC Beams Exposed to Standard Fire

Abstract

This paper presented the finite element (FE) models for thermal analysis of insulated CFRP-strengthened reinforcement concrete beams under standard fire condition. Based on these models, the influences of some parameters (e.g. thermal conductivity, thickness of fireproof coating, time of exposure to fire, and steel bar location) on thermal response were analyzed. The numerical results showed that the temperature at the surface of coating could be calculated by combining standard fire curve and time of fire exposure. The temperature at the surface of concrete beam decreased with the increase of coating thickness and increased linearly with the increase of thermal conductivity. The temperatures at internal concrete were only influenced by the temperature at the surface, the location from the surface and the time of fire exposure. After numerical analysis, a simplified calculating method was presented to predict the temperature value at any points of insulated CFRP-strengthened RC beam section, under standard fire condition. By comparing with the experimental results, the simplified method was well verified.