THE CONSTITUTIVE MODEL OF CONCRETE SUBJECTED TO SULFATE ATTACK BASED ON STATISTICAL DAMAGE THEORY

Based on the statistical damage theory and the test phenomenon, a statistical damage model for concrete under uniaxial and biaxial compression is proposed to consider the impact of sulphate attack. The deformation and failure of concrete is regarded as the continuous accumulation evolution of the two meso-damage modes, i.e., rupture and yield. Sulfate erosion effect changes the component and mechanical characteristics in the microstructure of concrete, and then changes the initiation and propagation process of microcracks. The above effects could be simulated by changing the probability distribution which characterizes the evolution process of the two meso-damage modes. The results show that in the sulphate erosion environment, the meso-damage cumulative evolution process would be significantly changed with the deepening of the degree of erosion, and finally causes the macro-mechanical properties of concrete exhibiting the phenomenon of ‘weakening’ after ‘strengthening’. During this process, the law of meso-damage evolution of the concrete shows obvious regularity, and it could be reflected by the five characteristic parameters in the statistical damage model. This paper presents a new method and tool to predict and analyze the damage mechanism of eroded concrete in complex environment.