基于渗透性能的混凝土耐久性预测模型

闫菲+王瑞骏+车明杰+贺新星

摘要：通过不同配合比混凝土试件的气体渗透性测试、吸水性测试及氯离子侵蚀试验，分析了混凝土氯离子扩散系数与渗透性能之间的关系，建立了基于渗透性能的混凝土耐久性预测模型，并以某临海水闸工程为例对所建模型进行验证。结果表明：空气渗透性系数、吸水性系数及氯离子扩散系数均随着水灰比的增大而增大；不同水灰比情况下，氯离子扩散系数均随空气渗透性系数、吸水性系数的增大而增大，且呈现一定的相关性；建立的基于渗透性能的混凝土耐久性预测模型，只需进行混凝土结构渗透性能的试验，即可预测混凝土结构的使用寿命；以某临海水闸工程为例对所建模型进行验证，认为该模型是可行的。建立基于渗透性能的混凝土耐久性预测模型对在氯离子环境下的混凝土结构工程直接利用渗透性能预测其使用寿命具有重要意义。

关键词：混凝土；渗透性能；氯离子侵蚀；耐久性预测模型

中图分类号：TV223.4 文献标识码：A 文章编号：1672-1683（2017）04-0161-07

Abstract：Through gas permeability test，water absorption test，and chloride ion erosion test of concrete samples with different mix proportions，this article has analyzed the relationship between the chloride ion diffusion coefficient and permeability，established a concrete durability prediction model based on permeability，and verified the model with a coastal sluice.The results showed that gas permeability coefficient，water absorption coefficient，and chloride ion diffusion coefficient would all increase with the increase of water cement ratio；in different water cement ratio conditions，chloride ion diffusion coefficient would increase with the increase of gas permeability and water absorption coefficient，showing a certain correlation between them.Just by testing the permeability of concrete structures，the established prediction model of concrete durability can predict the service life of the concrete structures.The model was verified and proven feasible with a coastal sluice.It has great significance in predicting the service life of concrete structures in chloride environment directly based on their permeability.

Key words：concrete；permeability；chloride ion erosion；durability prediction model

钢筋锈蚀是导致钢筋混凝土结构使用寿命降低的关键因素，而引起钢筋锈蚀的主要原因是在富含氯离子环境下，氯离子通过混凝土结构缺陷渗入，最终在钢筋表面聚集并达到临界浓度，且该过程中必须要有空气和水的存在[1-2]。混凝土的渗透性能主要体现在渗气性和渗水性这两方面，因此，混凝土的渗透性能是影响氯离子侵蚀的关键因素[3]。目前基于渗透性