Constitutive Model for Rubberized Concrete Passively Confined with FRP Laminates

This article develops an analysis-oriented stress-strain model for rubberized concrete (RuC) passively confined with fiber-reinforced polymer (FRP) composites. The model was calibrated using highly instrumented experiments on 38 cylinders with high rubber content (60% replacement of the total aggregate volume) tested under uniaxial compression. Parameters investigated include cylinder size (diameter×height: 100×200 mm or 150×300 mm), as well as amount (two, three, four, or six layers) and type of external confinement (carbon or aramid FRP sheets). FRP-confined rubberized concrete (FRP CRuC) develops high confinement effectiveness (fcc/fco up to 11) and extremely high deformability (axial strains up to 6%). It is shown that existing stress-strain models for FRP-confined conventional concrete do not predict the behavior of such highly deformable FRP CRuC. Based on the results, this study develops a new analysis-oriented model that predicts accurately the behavior of such concrete. This article contributes toward developing advanced constitutive models for analysis/design of sustainable high-value FRP CRuC components that can develop high deformability.