基于双应力的钢筋混凝土恒加试验腐蚀劣化规律研究  

Study on Corrosion Deterioration of Reinforced Concrete Under Constant Acceleration Test Based on Double Stress

作　　者：尚明刚 张云升 何忠茂[1,2] 乔宏霞 冯琼[1] 薛翠真[1] 韩照 SHANG Minggang;ZHANG Yunsheng;HE Zhongmao;QIAO Hongxia;FENG Qiong;XUE Cuizhen;HAN Zhao(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;College of Science&Technology Ningbo University,Ningbo 315211,Zhejiang,China)

机构地区：[1]兰州理工大学土木工程学院,兰州730050 [2]宁波大学科学技术学院,浙江宁波315211

出　　处：《材料导报》2022年第11期108-115,共8页Materials Reports

基　　金：国家自然科学基金(U21A20150,51878153,52178216,52008196);甘肃省青年科技基金(20JR5RA440);甘肃省优秀研究生“创新之星”项目(2021CXZX-485);甘肃省绿色智慧公路关键技术研究及示范(21ZD3GA002);兰州理工大学红柳一流学科建设计划资助;公路混凝土桥梁耐久性修复关键技术研究;重庆市科学技术局重点项目(cstc2021jscx-jbgs0029)。

摘　　要：针对钢筋混凝土耐久性试验周期长、数据离散性大的特点,选择高腐蚀性盐渍土作为导电介质,设计恒加速腐蚀试验。以一维和三维钢筋混凝土试件为研究对象,模拟了恒电流和腐蚀性离子的双应力加速劣化过程。在加速测试过程中采集了电化学阻抗谱(交流阻抗)数据、氯离子含量数据以及微观和宏观形貌数据,同时建立了基于对数正态分布的恒加试验腐蚀劣化统计模型。研究表明,石蜡防护层能够延长氯离子应力、恒电流应力和双应力作用下钢筋混凝土的平均寿命,延长后分别为249 h、268 h和115 h;恒电流应力最先作用于钢筋混凝土,贯穿裂缝的出现加速了氯离子应力的腐蚀作用,最后双应力叠加提高了钢筋混凝土腐蚀劣化速率;基于对数正态分布的恒加试验劣化模型能够实现石蜡防护效果的定量分析,氯离子、恒电流和双应力作用下的石蜡影响因子分别为0.41、0.35、0.19。In view of the characteristics of long durability test period and large data dispersion of reinforced concrete, high corrosive saline soil was selec-ted as conductive medium to design constant accelerated corrosion test. In this work, the deterioration process of the one-dimensional and the three-dimensional reinforced concrete specimens under double stress of constant current and corrosive ions was simulated. Electrochemical impedance spectroscopy(AC impedance) data, chloride ion content data, and microscopic and macroscopic morphology data were collected during the accelerated test. Meanwhile, a statistical model of corrosion degradation in constant acceleration test based on lognormal distribution was established. The results have shown that the paraffin protective layer can increase the average life of reinforced concrete under chloride stress, constant current stress, and double stress by 249 h, 268 h and 115 h, respectively.The constant current stress firstly acts on the reinforced concrete, and the appearance of penetrating crack accelerates the corrosion effect of chloride ion stress. Finally, the double stress superposition increases the corrosion deterioration rate of reinforced concrete. The deterioration model of constant addition test based on lognormal distribution can realize the quantitative analysis of the protective effect of paraffin, and the influence factors of paraffin under chloride ion, constant current and double stress are 0.41, 0.35 and 0.19, respectively.

关 键 词：石蜡隔离层 恒电流加速 极大似然估计 腐蚀影响因子 

分 类 号：TU528[建筑科学—建筑技术科学]