STUDY ON THE COMPRESSIVE CONSTITUTIVE MODEL OF CONCRETE CONFINED BY HIGH-STRENGTH STAINLESS STEEL WIRE MESHES/ECC

To investigate the application of the novel composite material 'high-strength stainless steel wire mesh/ECC confined concrete' in engineering practice, based on the axial compression test results of high-strength stainless steel wire mesh/ECC confined high strength concrete (referred to as HSME confined high strength concrete) components, the effects of ECC's strength, strength of core concrete and transverse steel strand reinforcement ratio on the compressive performance are investigated and analyzed. The test results indicate that the HSME can effectively constrain the core concrete, and the specimens exhibit ductile failure pattern. The compressive stress-strain curves of the HSME confined high strength concrete are obtained based on the test results, which include three stages: elastic stage, elastoplastic stage and descending stage. According to the mathematical characteristics of the stress-strain curve at each stage, the constitutive model of HSME confined high strength concrete under the whole loading process is established. The ECC characteristic value and the transverse steel strand characteristic value are introduced to analyze various parameters of the proposed constitutive model. Then, the formulas of cracking strain under compression, peak stress, strain at the peak stress and the ultimate compressive strain, et al, are proposed. The stress-strain curves are obtained by substituting parameters into the proposed compressive constitutive relationship, which are in good agreement with the stress-strain curves obtained from the test results. The ratios of calculated value to the test value for the cracking strain under compression and the ultimate compressive strain are within 0.949-1.068 and 0.938-1.039, respectively. It demonstrates that the proposed compression constitutive model could accurately describe the stress-strain relationship of the HSME confined high strength concrete.