既有混凝土码头的时变氯离子扩散过程

发布时间：2018-02-28 09:30

本文关键词： 混凝土氯离子扩散暴露环境时间参数　出处：《上海交通大学学报》2017年04期 　论文类型：期刊论文

【摘要】：为了研究不同暴露环境(大气区、潮差区和浪溅区)对氯离子在混凝土中传输的影响,以及氯离子扩散过程的时变特性,对北部湾某码头的混凝土现场耐久性进行了检测,得到了不同深度混凝土试样的自由氯离子浓度.结果表明,在同一侵蚀深度,浪溅区的氯离子浓度最大,潮差区的次之,大气区的最小,拟合得到的表面氯离子浓度和表观氯离子扩散系数亦表现出了相同特性;浪溅区是影响临海钢筋混凝土结构耐久性的最不利暴露环境;氯离子扩散系数随侵蚀时间递减,时间参数为服从正态分布的随机变量,大气区、潮差区和浪溅区时间参数的均值分别为0.19,0.36和0.43;在钢筋混凝土结构的耐久性分析中应考虑氯离子扩散系数的时变特性.
[Abstract]:In order to study the influence of different exposure environment (large gas area, tidal zone and splash zone) on chloride ion transport in concrete, and the time-varying characteristics of chloride ion diffusion process, the durability of concrete in a pier in Beibu Bay was tested. The free chloride concentration of concrete samples with different depths is obtained. The results show that the concentration of chlorine ion in the splash zone is the highest, the lowest in the tidal range and the smallest in the large gas area at the same erosion depth. The surface chlorine ion concentration and apparent chloride ion diffusion coefficient also show the same characteristics, the splash zone is the most unfavorable exposure environment affecting the durability of reinforced concrete structures near the sea, and the chloride ion diffusion coefficient decreases with the erosion time. The time parameters are random variables from normal distribution, the mean values of time parameters in large air region, tidal zone and splash zone are 0.19 ~ 0.36 and 0.43 respectively, and the time-varying characteristics of chloride diffusion coefficient should be considered in the durability analysis of reinforced concrete structures.
【作者单位】：上海交通大学船舶海洋与建筑工程学院;
【基金】：国家自然科学基金(41274012)资助项目
【分类号】：TV332;U657

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