Nonlinear analysis of FRP-strengthened reinforced concrete slabs under fire

Abstract:

This paper presented a numerical model of FRP-strengthened reinforced concrete(RC) slabs under fire and conducted the coupled thermo-mechanical analysis.Based on the information about the temperature-dependent mechanical properties of concrete,reinforcing steel and FRP materials,this study developed a nonlinear finite element(FE) code to investigate the fire performance of FRP strengthened RC slabs.The FE code was verified through comparisons with existing fire tests.Based on the code,the effects of intumescent coating thickness,fire load ratio,longitudinal steel reinforcement,amount of FRP strengthening,sectional height and concrete cover on the mid-span deflection of FRP-strengthened RC slabs under fire were considered.The parametric studies show that intumescent coating thickness,fire load ratio and amount of FRP strengthening have significant effects on fire performance of strengthened slabs;sectional height and concrete cover only have moderate influences;and mid-span deflection versus longitudinal steel reinforcement is not obvious.