Prediction on stress-strain behavior of FRP-confined concrete with passive confinement-based 3D constitutive model

Abstract

The confinement through fiber reinforced polymer (FRP) wrapping belongs to passive confinement. Since the concrete is a path-dependent material, the passive confinement causes typical stress-strain behavior of concrete which is different from concrete under active confinement. The first author’s research group have developed the true-triaxial database associated with the passive confinement by the novel true-triaxial testing system. Accordingly, two types of 3D constitutive models for FRP confined concrete are proposed. They are analysis-oriented and FEM-based constitutive models, which can simulate the compression behavior of concrete square columns with FRP confinement. The well-matched performance demonstrates the improved constitutive models’ applicability in simulating the mechanical behavior of concrete with complex passive confinement fields. At last, the arching effect was re-examined for the square section.