新老混凝土界面区氯离子传输特征与模型  

Transport characteristics and models of chloride ions in the interfacial zone of new-old concrete

作　　者：李富民[1] 武晓辉 陈志祥 Li Fumin;Wu Xiaohui;Chen Zhixiang(Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学江苏省土木工程环境灾变与结构可靠性重点实验室,徐州221116

出　　处：《东南大学学报（自然科学版）》2023年第3期425-435,共11页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51878656).

摘　　要：为研究新老混凝土界面区氯离子传输的特征及模型,制作了不同水灰比搭配、不同界面凿毛深度的新老混凝土接合体试件,进行为期90 d的氯盐溶液干湿循环侵蚀试验.然后对各试件不同位置处的氯离子浓度进行测试,据此分析界面区氯离子传输特征,并结合相关文献中本体混凝土氯离子传输模型建立界面区氯离子传输模型.结果表明:界面区氯离子浓度明显高于两侧新老混凝土本体区域,氯离子传输存在典型的界面区效应;当新老混凝土水灰比相同且界面未凿毛时,界面区呈现出良好的对称性;而当水灰比不同或(和)界面凿毛时,界面区呈现出非对称性,界面区重心偏向水灰比较高的老混凝土一侧,且水灰比差距越大或(和)凿毛深度越大,界面区向老混凝土一侧的偏移也越多,同时界面区效应水平也越弱.通过与其他试验结果的对比,验证了界面区氯离子传输模型具有较好的适用性.In order to study the transport characteristics and quantitative models of chloride ions in the interfacial zones of new-old concrete,some annectent new-old concrete specimens with different water-cement ratios and different chiseled depths of interfaces were made and subjected to dry-wet cyclic exposure in chlorine solution for 90 d,and then the chloride ion concentration at different positions of each specimen was measured.According to the test results,the transport characteristics of chloride ions in the interfacial zones were analyzed,and the transport models of chloride ions in the interfacial zones were established combined with the models for ontic concrete in the literature.The results show that the chloride ion concentration in the interfacial zones is significantly higher than that in the ontic areas of new and old concrete on both sides,namely,the chloride ions transport has a typical interfacial zone effect.When the water-cement ratios of new and old concrete are the same and the interfaces are not chiseled,the interfacial zones show good symmetry.However,when the water-cement ratios are different or(and)the interfaces are chiseled,the interfacial zones present asymmetry,and the centers of gravity of the interfacial zones tend to the side of the old concrete with high water-cement ratio;the larger the water-cement ratio gap or(and)the depth of chiseled pits,the more the interfacial zones deviate to the old concrete side,and the lower the interfacial zone effect level.By comparison with other test results,it is verified that the chloride ion transport models in the interfacial zones have good applicability.

关 键 词：装配式结构 新老混凝土 界面区 耐久性 氯离子传输 

分 类 号：TU503[建筑科学—建筑技术科学]