Empirical and precise finite element modelling of bond-slip contact behavior between heat-damaged concrete and anchored CFRP composites with groove

Abstract

Predicting the overall capacity of Reinforced Concrete (RC) structures strengthened with Carbon Fiber Reinforced Polymers (CFRP) is challenging due to the difficulties in addressing their bond strength accurately. Concerns regarding the predicting accuracy are induced, including debonding probability, strengthening anchorage, and constituent material’s degradation due to sudden action such as exposure to high temperatures. This study presents a new bond-slip relationship for predicting the bond-slippage behavior of groove-anchored CFRP-strengthened members exposed to heat-damage effect using the nonlinear finite element analysis (NLFEA) method. The new model was generated using various high-temperature levels from 23° C to 800° C, CFRP bonded length (L_f) (0.1 L_c(length of the concrete specimen) to 1.0 L_c), CFRP bonded width (b_f) (0.1b_c(width of the concrete specimen) to 1.0b_c), and anchored groove numbers (0−3). The simulation was accomplished using ANSYS software and its accuracy was ensured using the precisely captured lateral strain values and overall distribution within the CFRP strips at the interface area. It was observed that normal and lateral stress contours were irregularly distributed within the CFRP strip width, whereas a regular distribution was captured in the other two directions. The new models were compared with experimental and theoretical models from the literature where high predictability was demonstrated compared to high disturbance and errors for the other existing models.