Analytical modeling of the static behaviour of CFRP-strengthened RC beams subjected to freeze–thaw cycles

This paper presents an analytical model for predicting the flexural strength of reinforced concrete (RC) beams strengthened with carbon fibre-reinforced polymer (CFRP) sheets, including the effects of freeze–thaw (F/T) exposure. The model integrates nonlinear material behaviour and accounts for parameters influencing the flexural behaviour of CFRP-strengthened RC beams. The model combines the fibre method with established failure criteria and was validated against an experimental database of 98 RC beams strengthened with CFRP sheets. Also, the model includes F/T-concrete stress-strain curves as well as the degradation of concrete/CFRP interface and accounts for elastic-plastic properties of steel reinforcements and elastic properties of CFRP reinforcements. The validation confirms the accuracy and reliability of the developed model in predicting the behaviour of CFRP-strengthened RC beams under freeze–thaw conditions. A comparison of the proposed analytical model versus the available design provisions indicates that the analytical model has the best fitting with the experimental data.