Plasticity constitutive modeling of partially confined concrete with steel jacketing

Current research offers experimental and numerical investigation on concrete blocks with partial steel jackets, which endures axial compression. Experimental procedure provides the primary data for calibration of proposed model. Specimens have various steel jacketing ratios and the load is axial compression. The recorded data are strain components, elongation and the resisted force in experiment. A continuous cap plasticity surface expresses the non-uniform expansion and contraction of concrete beside an isotropic damage law that models the strength degradation using AbaqusA (R) code. In presented mathematical model, the contraction and dilation of concrete is function of lateral pressure provided by steel jackets. The confining pressure is non-uniform due to discrete arrangement of steel ties in jacket and yielding of steel as concrete expands. Model provides parametric curves in order to design the confined-to-unconfined strength and ductility capacities of confined concrete. The presented numerical model is in close agreement with experimental results based on acquired results. We derive finally parametric curves for ductility and strength of confined concrete for various jacketing ratios.