氯盐-锈蚀耦合损伤混凝土抗压强度试验  

EXPERIMENTAL RESEARCH ON COMPRESSIVE STRENGTH OF CONCRETE DAMAGED BY COUPLING OF CHLORINE-CORROSION

作　　者：钟小平[1,2] 彭蓝鸽 袁承斌 陈勇[1] 张博 ZHONG Xiaoping;PENG Lange;YUAN Chengbin;CHEN Yong;ZHANG Bo(College of Civil Science and Engineering,Yangzhou University,Yangzhou 225127,China;College of Hydraulic Science and Engineering,Yangzhou University,Yangzhou 225009,China;Hulun Buir Botai Engineering Consulting Co.,Ltd.,Hulun Buir 021000,China)

机构地区：[1]扬州大学建筑科学与工程学院,江苏扬州225127 [2]扬州大学水利科学与工程学院,江苏扬州225009 [3]呼伦贝尔市博泰工程咨询有限公司,内蒙古呼伦贝尔021000

出　　处：《工业建筑》2020年第12期69-75,共7页Industrial Construction

基　　金：国家自然科学基金资助项目(51678513,51278444);江苏高校优势学科建设工程资助项目。

摘　　要：为研究氯盐环境下混凝土力学性能的退化规律,采用质量分数为5%的NaCl溶液,对混凝土试件进行干湿循环、恒电流通电的加速腐蚀试验,获得了氯盐侵蚀及氯盐-钢筋锈蚀耦合作用下损伤混凝土试件,并对其进行抗压力学性能研究。研究结果表明:氯盐侵蚀单因素作用下,混凝土抗压强度随干湿循环时间增加呈先增大后减小的趋势,最大增幅为16.6%;氯盐-钢筋锈蚀耦合作用下,随着钢筋锈蚀率增大,抗压强度总体呈下降趋势,且前期降幅较后期快。当锈蚀率达到6.3%时,抗压强度较初始未损伤强度降低了19.4%,锈蚀率达到14.9%时,混凝土抗压强度降低了24.5%。锈蚀损伤是混凝土强度降低的主要原因,分别采用锈蚀率及锈胀裂缝宽度作为强度损伤变量,对试验结果进行回归分析,建立了氯盐-锈蚀耦合损伤混凝土抗压强度劣化计算模型。Accelerated corrosion testing on concrete specimens was carried out under the action of dry-wet cycle and constant-current power with using the mass fraction of 5%NaCl solution to investigate the degradation law of mechanical properties of concrete in chloride environment.The concrete specimens damaged by chloride erosion and coupling of chlorine-rebar corrosion were obtained,and then the compressive strength of concrete specimens was studied.The results showed that under the action of single factor for chloride erosion,the compressive strength of concrete increased first and then decreased with the increase of time of dry-wet cycle,with a maximum increase of 16.6%;under chlorine-rebar corrosion coupling,the compressive strength of concrete generally decreased with the corrosion rate of reinforcement increases,and the decrease in the early stage was faster than that in the later stage.When the corrosion rate reached 6.3%,the compressive strength was 19.4%lower than the initial undamaged strength;when the corrosion rate reached 14.9%,the compressive strength of concrete decreased by 24.5%.Corrosion damage was the main reason of the decrease of concrete strength,the corrosion rate and the corrosion-induced crack width were selected as the strength damage variables respectively to analyze regressively the test data,and consequently established the calculation models on compressive strength deterioration of concrete damaged by chlorine-corrosion coupling.

关 键 词：氯盐环境 损伤混凝土 锈蚀率 锈胀裂缝 抗压强度 

分 类 号：TU528[建筑科学—建筑技术科学]