冻融-干湿作用下装配式结构节点部位的氯离子传输特性  

Chloride Transport Properties at Joints of Prefabricated Structures under Freeze-Thaw-Dry-Wet Cycles

作　　者：包龙生[1] 赵家康 李练武 包宇扬 杨宇豪 BAO Longsheng;ZHAO Jiakang;LI Lianwu;BAO Yuyang;YANG Yuhao(School of Transportation and Geomatics Engineering,Shenyang Jianzhu University,Shenyang,China,110168;School of Civil Engineering,Shenyang Jianzhu University,Shenyang,China,110168;School of Applied Technology,Shenyang University,Shenyang,China,110044;School of Architectural and Civil Engineering,Shenyang University of Technology,Shenyang,China,110870)

机构地区：[1]沈阳建筑大学交通与测绘工程学院,辽宁沈阳110168 [2]沈阳建筑大学土木工程学院,辽宁沈阳110168 [3]沈阳大学应用技术学院,辽宁沈阳110044 [4]沈阳工业大学建筑与土木工程学院,辽宁沈阳110870

出　　处：《沈阳建筑大学学报（自然科学版）》2023年第2期271-277,共7页Journal of Shenyang Jianzhu University：Natural Science

基　　金：“十三五”国家重点研发计划重点专项基金项目(2018YFC0809600,2018YFC0809606);辽宁省重点研发计划基金项目(2018416028);沈阳市建委城乡系统科研项目(201904);沈阳市科技计划项目(21-108-9-13)。

摘　　要：目的 研究冻融-干湿循环作用下装配式混凝土结构节点部位的氯离子传输特性,为北方寒区装配式结构的发展提供理论基础。方法 在Fick第二定律的基础上推导氯离子在扩散和冻融作用下的偏微分方程,建立数值模型模拟冻融与氯盐干湿侵蚀交替作用下氯离子在装配式混凝土结构节点部位的传输过程。结果 在冻融-干湿循环作用下氯离子逐渐向混凝土内部扩散,随着侵蚀深度的增加,氯离子质量分数逐渐降低;在侵蚀深度10 mm处,冻融-干湿循环50次后的氯离子质量分数为0.246%,可以发现经历100次、150次、200次、250次、300次循环后,节点部位氯离子质量分数分别较经历50次循环增加了66.3%、99.2%、134.6%、164.2%、173.6%。结论 节点与其他部位相比受到氯离子的侵蚀作用更强;随着冻融-干湿循环次数的增加,氯离子质量分数增速放缓,各部位冻融破坏程度均增加。The chloride transport characteristics at joints of prefabricated concrete structures under freeze-thaw-dry-wet cycles are studied to provide a theoretical basis for the development of prefabricated structures in the northern cold regions.Based on the Fick′s second law,the partial differential equation of chloride ion under the action of diffusion and freeze-thaw is deduced.The finite element analysis software is used to simulate the transmission process of chloride ion at the joints of prefabricated concrete structures under the alternating action of freeze-thaw and chloride dry-wet erosion.The results show that under the action of freeze-thaw-dry-wet cycles,chloride ion gradually diffuses into the concrete,and its mass fraction gradually decreases with the increase of erosion depth.At the erosion depth of 10 mm,the mass fraction of chloride ion after 50 freeze-thaw-dry-wet cycles is 0.246%.It can be found that after 100,150,200,250,and 300 cycles,respectively,the mass fraction of chloride ion at the joints is higher than that of the experienced 50 cycles increased by 66.3%,99.2%,134.6%,164.2%and 173.6%,respectively.The joints are more severely corroded by chloride ion than other parts.With the increase of freeze-thaw-dry-wet cycles,the growth rate of chloride ion mass fraction slows down,and the degree of freeze-thaw damage in each part increases.

关 键 词：装配式混凝土结构 节点 干湿循环 冻融循环 氯离子 FICK第二定律 

分 类 号：TU528.01[建筑科学—建筑技术科学]