Nonlinear Analysis of Insulated Carbon Fiber Reinforced Polymer Strengthened Reinforced Concrete Beams in Fire

Abstract:

Based on the reliable models of mechanical properties degradation of concrete,steel reinforement steel and carbon fiber reinforced polymer (CFRP) materials with increasing temperature being taken into account,the paper presents a numerical model of insulated CFRP strengthened reinforced concrete beams and a nonlinear finite element method (FEM) program (named NFACCB) of strengthened beams under exposure of fire event with the generalpurpose code ANSYS.Moreover,the coupled thermomechanical is analyzed.The simulated results show that although CFRPs are sensitive to elevated temperature,satisfactory fire performance behaviour can be achieved by providing reasonably supplemental fire insulation.Fire insulation thickness and fire load ratio have a significant effect on fire performance of strengthened beams;while the influence of longitudinal bar reinforcement,the amount of CFRP strengthening,the thermal conductivity of insulation materials and sectional dimension are moderate;the influence of the midspan deformations with thermal specific heat and density is the least.