Peak Strength Expression for Concrete Confined with Fiber-Reinforced Polymer

This study obtains a three-dimensional unified peak strength expression for confined concrete from the reported experimental results of circular concrete columns confined with different fiber-reinforced polymer (FRP) materials under axial compressive load for application in pile design. The reported experimental results are divided into two groups: FRP-wrapped and FRP tube-encased specimens. An assessment using various statistical indicators is carried out to evaluate the performance of existing predictive equations for peak strength. A reliability analysis of the models is conducted using the advanced first-order second-moment approach. Based on the assessment, it is inferred that most of the models conform to the reliability index criteria suggested by current requirements for structural concrete. (C) 2018 American Society of Civil Engineers.