氯离子在带接缝混凝土内的传输规律研究  

Research on transportation mechanism of chloride ion in concrete with joint

作　　者：延永东[1] 司有栋 陆春华[1] 高生宇 刘雪扬 YAN Yongdong;SI Youdong;LU Chunhua;GAO Shengyu;LIU Xueyang(Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang 212013,Jiangsu,China;Shanghai Baoye Group Corp.,Ltd.,Shanghai 201941,China)

机构地区：[1]江苏大学土木工程与力学学院,江苏镇江212013 [2]上海宝冶集团有限公司,上海201941

出　　处：《建筑科学与工程学报》2023年第1期49-56,共8页Journal of Architecture and Civil Engineering

基　　金：江苏省普通高校研究生科研创新计划项目(SJCX_1689);国家自然科学基金项目(51878319,51778272)。

摘　　要：为得出不同类型接缝及石灰石粉含量对混凝土构件在氯盐环境中的耐久性影响,设计了一侧为普通混凝土、另一侧为石灰石粉混凝土、中间为不同类型接缝的组合试件。将养护后的试件在10%浓度的氯盐溶液中浸泡270 d后取样,检测接缝处及其两侧混凝土内的自由氯离子浓度。结果表明:在同一试件内,接缝处的氯离子浓度最大,距接缝0~20 mm处混凝土内的氯离子浓度向远离接缝方向逐渐减小,距接缝20 mm之外混凝土内的氯离子浓度基本相等;相同侵蚀时间下,同一深度处直接湿接缝内的氯离子浓度最大,凿毛接缝处次之,界面剂接缝处最小,拟合得出的3种接缝处的表观氯离子扩散系数分别为基体混凝土的1.95倍、1.87倍、1.83倍;接缝两侧相同距离处,掺石灰石粉混凝土内的氯离子浓度均大于普通混凝土,石灰石粉掺量(质量分数)为10%、20%、30%时混凝土表观氯离子扩散系数分别增大9.8%、11.8%、65.8%;数值模拟得到的氯离子在带接缝混凝土内的分布规律与试验结果吻合较好。In order to obtain the influence of different types of joints and limestone powder contents on the durability of concrete members in chloride environment,composite specimens with one side of ordinary concrete,the other side of limestone powder concrete and the middle of different types of joints were designed.The cured specimens were immersed in 10%chloride ion concentration salt solution for 270 d,and then the specimens were taken to detect the free chloride ion concentration at the joint and the concrete on both sides.The results show that,in the same specimen,the chloride ion concentration at the joint is the largest,and the chloride ion concentration decreases gradually away from the joint in the concrete at 0-20 mm from the joint.The chloride ion concentration in concrete is basically equal at 20 mm away from the joint.Under the same erosion time,the chloride ion concentration in the direct wet joint at the same depth is the largest,followed by the rough joint,and the interface agent joint is the smallest.The chloride ion diffusion coefficients at the three joints obtained by fitting are 1.95 times,1.87 times and 1.83 times that of the matrix concrete,respectively.At the same distance on both sides of the joint,the chloride ion concentration in concrete with limestone powder is greater than that in ordinary concrete.When the limestone powder content(mass fraction)is 10%,20%and 30%,the chloride ion diffusion coefficient of concrete increases by 9.8%,11.8%and 65.8%,respectively.The distribution of chloride ions in jointed concrete obtained by numerical simulation is in good agreement with the experimental results.

关 键 词：混凝土接缝 石灰石粉 氯离子 数值模拟 

分 类 号：TU528.45[建筑科学—建筑技术科学]