干湿循环作用下风积沙混凝土中氯离子扩散研究  

Chloride Ion Transport in Aeolian Sand Concrete under Dry-Wet Cycles

作　　者：董伟 王栋 刘鑫[2,3] 申向东 薛刚[1] DONG Wei;WANG Dong;LIU Xin;SHEN Xiangdong;XUE Gang(College of Civil Engineering,Inner Mongolia University of Science&Technology,Baotou,China,014010;Water Conservancy and Civil Engineering College,Inner Mongolia Agricultural University,Hohhot,China 010018;Department of Civil Engineering,Ordos Institute of Technology,Ordos,China,017000)

机构地区：[1]内蒙古科技大学土木工程学院,内蒙古包头014010 [2]内蒙古农业大学水利与土木建筑工程学院,内蒙古呼和浩特010018 [3]鄂尔多斯应用技术学院土木工程系,内蒙古鄂尔多斯017000

出　　处：《沈阳建筑大学学报（自然科学版）》2022年第5期904-911,共8页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51769025);内蒙古自治区自然科学基金项目(2020BS05008,2021LHMS05019);内蒙古科技大学创新基金项目(2019QDL-B48)。

摘　　要：目的 探究不同风积沙替代率的混凝土在干湿循环作用下对其内部氯离子扩散的影响,研究氯离子在干湿循环中的传输特性。方法 通过制备0%、25%、50%、75%、100%风积沙替代河砂的混凝土,采用磨粉滴定的方法测定不同干湿循环周期下混凝土中不同深度处的总氯离子和自由氯离子浓度,并就4种结合机制探讨氯离子结合规律。结果 自由氯离子浓度随风积沙替代率的增大先减小后增大,并且干湿循环作用对混凝土表层氯离子浓度影响较大。风积沙混凝土氯离子结合规律均符合线性结合类型,随着风积沙替代率的增大,混凝土氯离子结合能力先增大后减小。风积沙替代率为25%时混凝土自由氯离子浓度最低,结合能力最好,其结合能力为基准混凝土的1.20倍,而替代率100%的风积沙混凝土反而不利于混凝土抵抗氯离子侵蚀。结论 风积沙替代率小于50%时,风积沙混凝土的氯离子结合能力和抗氯离子侵蚀能力较好,对钢筋的保护能力比普通混凝土更强。The influence of concrete with different amount of aeolian sand on the internal chloride ion diffusion under dry wet cycle was studied,and the transmission characteristics of chloride ion in dry wet cycle were studied.Concrete samples with 0%,25%,50%,75% and 100% aeolian sand instead of river sand were prepared.And the concentrations of total chloride ion and free chloride ion at different depths in concrete under different dry and wet cycles were measured by grinding titration,and the binding law of chloride ion was discussed combined with four binding mechanisms.The results show that the free chloride ion concentration first decreases and then increases with the increase of the content of aeolian sand.The dry wet cycle has a great influence on the chloride ion concentration on the concrete surface.The chloride ion binding law of aeolian sand concrete conforms to the linear binding type.With the increase of the content of aeolian sand,the chloride ion binding capacity of concrete first increases and then decreases.When the content of aeolian sand is 25%,the free chloride ion content of concrete is the lowest and the binding capacity is the best,and its binding capacity is 1.20 times that of the reference concrete.However,100% aeolian sand concrete is not conducive to the resistance of concrete to chloride ion erosion.When the replacement rate of aeolian sand is less than 50%,the chloride ion binding ability and chloride ion corrosion resistance of concrete are better,and the protection ability to reinforcement is stronger than that of ordinary concrete.

关 键 词：干湿循环 自由氯离子 风积沙替代率 风积沙混凝土 

分 类 号：TU528[建筑科学—建筑技术科学]