硅烷憎水处理混凝土的氯离子电场迁移模型研究

All right reserved. Electrical migration test is a common method to evaluate concrete's resistance to the chloride-ion penetration. However, it has been found that the existing migration models are not accurate enough to interpret the test results due to neglecting the effect of pore structure distribution in concrete on the migration process. Stanish et al. proposed a new model by considering the random characteristics of chloride migration velocity and found that the model prediction agreed well with the test results. Based on Stanish's model, a simplified model is further developed herein by assuming that the chloride diffusion coefficient instead of the chloride migration velocity follows a logarithmic normal distribution. This assumption reflects more directly the random characteristics of concrete pore structures. It can simplify the solutions to a large extent with the same accuracy of prediction. This simplified model was verified to be also applicable to the migration tests of silane-based water repellent concrete. It was revealed that the silane-based water repellent only affected the surface chloride concentration during the migration tests. The measured electric flux can reflect the influence of silane-based water repellent on the penetration of chloride ions, however, the silver nitrate colorimetric method is inapplicable to evaluating the chloride resistance of concrete with silane-based water repellent.