Mechanical properties of steel reinforced coral aggregate concrete column under uniaxial compression

The production of coral aggregate concrete (CAC) from coral debris effectively addresses the lack of building materials in island construction. Due to the low compressive strength and visible brittleness of CAC, steel reinforcement with anti-rust treatment is adopted to improve the mechanical properties of CAC. This paper presents an experimental study on the mechanical behavior of 45 anti-rust coated steel reinforced coral aggregate concrete (RCAC) columns under uniaxial compression, designed with the consideration of concrete strength and configurations of the transverse reinforcement. The test results show that the volumetric ratio of lateral confinement can improve the compressive strength and ductility of RCAC effectively. The strengthening effect of diamond-shaped composite and spiral hoop is higher, while that of rectangular hoop is slightly weaker. The increase of concrete strength has a significant positive effect on the peak stress, but not on the peak strain. Based on the experiments, the formulae for the peak stress and peak strain of RCAC are given, and the constitutive model of RCAC is proposed. Moreover, the calculation method of the theoretical bearing capacity is arrived at, and the predicted values with a specific safety reserve are close to the measured values.