Abstract: Deterioration of mechanical behavior of concrete structures results from the leaching of calcium ion in concrete pore solution,which is caused by water.Based on the experimental data,a new coupled constitutive model of chemical-mechanical damage is presented.An isotropic damage variable is used to describe the chemical-mechanical damage.The calcium concentration in concrete pore solution satisfies the nonlinear diffusion equation of calcium mass conservation.The results of finite element computations and experiments demonstrate that the calculated values agree very well with the testing data and the model can describe the chemical-mechanical coupling effects fairly.