Load path dependence of strain and stress for confined concrete Available to Purchase

The assumption of load-path independence of strain and stress has been widely adopted as the basis for building analysis-oriented models of fibre-reinforced polymer (FRP)-confined concrete. This assumption facilitates the application of stress–strain models to actively confined concrete in FRP-confined (or passively confined) concrete. However, consensus on the path independence of concrete has not yet been reached. In this study, an investigation into the influence of stress path on concrete mechanical behaviour was conducted by assessing the models of actively confined concrete and comparing the results of the most accurate active confinement model with the experimental results for FRP-confined concrete cylinders at the same confinement pressures. The influence of two confinement systems on strain and axial stress under the same lateral pressures was studied in detail. The results show that strain and axial stress are path dependent. The loading-path effect on both axial strain and stress is related to the lateral stiffness ratio. Based on the confirmation of the path dependence in the confined concrete, a modified analysis-oriented model is proposed. The model has good performance in predicting the stress–strain behaviour of FRP-confined concrete.