摘要: |
In the light of the characteristics of concrete under sulphate attack,a two-dimension cellular automaton model is developed based on the fundamental of cellular automata to simulate the diffusion transfer process of sulphate ions in concrete,and the distinction between the cellular automata and the traditional finite difference method is analyzed.The calculation formula of effective stress in concrete under sulphate attack is proposed on the basis of the transformation relation among the corrosion depth of concrete,the extent of corrosion and the effective loading area of concrete.In combination with the characteristics of the concrete creep model B3,a modified B3 model is presented to predict the time-dependent deformations of concrete under coupled effects of sustained loading and sulphate attack.To validate the modified model,an experiment was carried out to examine the long term deformations of concrete under sustained loading in the sodium sulphate solution(the concentration of sulphate ions is 1% and 5%,respectively).The results show that the two-dimension cellular automaton model is applicable to simulate the diffusion transfer process of sulphate ions in concrete and the prediction value of modified B3 model is in good agreement with the experimental data.The method that modification of B3 model theoretically improves the approaches for the study of concrete durability as well as the prediction of concrete time-dependent deformations under the situation of actual engineering effects. |