Prediction of compressive strength of FRP-confined concrete square columns using fuzzy logic approach

The behavior and modeling of circular concrete sections confined by Fiber Reinforced Polymer (FRP) wraps have been recently studied extensively while non-circular sections have received much less attention. This study focuses on FRP-confined specimens with square sections under axial loading. A fuzzy logic based model is developed to predict the compressive strength of the FRP-confined square sections. The explicit formation of the proposed fuzzy model for the compressive strength of FRP-confined concrete is presented as a function of the section width، corner radius، compressive strength of unconfined concrete، thickness of FRP sheets، tensile strength and elastic modulus of FRP materials. The results indicated that the accuracy of the proposed fuzzy model is quite satisfactory as compared to a large database containing experimental results of 182 specimens assembled from the open literature. Moreover، the proposed fuzzy model is compared with the existing nine models developed by various researchers and is found to be more accurate.