西安建筑科技大学学报(自然科学版)

对经历不同冻融循环次数钢筋混凝土棱柱体进行了通电加速锈蚀试验,研究了混凝土强度等级、冻融循环次数和保护层厚度对钢筋临界锈蚀率的影响,并通过DIC技术监测了钢筋锈蚀全过程.试验结果表明:混凝土抗压强度随冻融循环次数增加而降低.钢筋临界锈蚀率随保护厚度与钢筋直径之比(c/d)的增大整体呈上升趋势,但随冻融循环次数增加而减小.

Accelerated corrosion tests were carried out on reinforced concrete prismatic specimens with different freeze-thaw cycles, and the influences of concrete strength grade, freeze-thaw cycles and protective layer thickness on critical corrosion rate of reinforcement were studied. The whole process of reinforcement corrosion was monitored by DIC technology. The test results showed that the compressive strength of concrete decreased with the increase of freeze-thaw cycles. The critical corrosion rate of reinforcement increased with the increase of the ratio of protection thickness to reinforcement diameter (c/d), but decreased with the increase of the number of freeze-thaw cycles.

引言
1 试验概况
2 试验结果分析与讨论
3 结论

表1 钢筋混凝土试件分组表<br/>Tab.1 Group table of reinforced concrete specimens

表1 钢筋混凝土试件分组表
Tab.1 Group table of reinforced concrete specimens

图1 钢筋混凝土试件尺寸<br/>Fig.1 Size of reinforced concrete specimen

图1 钢筋混凝土试件尺寸
Fig.1 Size of reinforced concrete specimen

图2 钢筋预处理示意图<br/>Fig.2 Schematic diagram of reinforcement pretreatment

图2 钢筋预处理示意图
Fig.2 Schematic diagram of reinforcement pretreatment

图3 冻融试验温度变化<br/>Fig.3 Temperature change of freeze-thaw test

图3 冻融试验温度变化
Fig.3 Temperature change of freeze-thaw test

图4 冻融损伤混凝土受压破坏形态<br/>Fig.4 Compression failure pattern of freeze-thaw damaged concrete

图4 冻融损伤混凝土受压破坏形态
Fig.4 Compression failure pattern of freeze-thaw damaged concrete

图5 不同冻融循环次数下的混凝土抗压强度<br/>Fig.5 Compressive strength of concrete under different freeze-thaw cycles

图5 不同冻融循环次数下的混凝土抗压强度
Fig.5 Compressive strength of concrete under different freeze-thaw cycles

图6 图像处理过程<br/>Fig.6 Image processing process

图6 图像处理过程
Fig.6 Image processing process

图7 混凝土锈蚀过程表面应变云图<br/>Fig.7 Surface strain nephogram of concrete corrosion process

图7 混凝土锈蚀过程表面应变云图
Fig.7 Surface strain nephogram of concrete corrosion process

图8 锈胀开裂时刻保护层混凝土表面形貌<br/>Fig.8 Surface morphology of concrete cover at the time of rust expansion cracking

图8 锈胀开裂时刻保护层混凝土表面形貌
Fig.8 Surface morphology of concrete cover at the time of rust expansion cracking

表2 钢筋锈蚀率试验结果<br/>Tab.2 Test results of steel corrosion rate

表2 钢筋锈蚀率试验结果
Tab.2 Test results of steel corrosion rate

图9 钢筋锈蚀率随混凝土强度等级的变化<br/>Fig.9 Variations of steel corrosion rate with concrete strength grade

图9 钢筋锈蚀率随混凝土强度等级的变化
Fig.9 Variations of steel corrosion rate with concrete strength grade

图10 钢筋锈蚀率随冻融循环次数变化规律<br/>Fig.10 Variations of steel corrosion rate with the number of freeze-thaw cycles

图10 钢筋锈蚀率随冻融循环次数变化规律
Fig.10 Variations of steel corrosion rate with the number of freeze-thaw cycles

图11 钢筋锈蚀率随混凝土保护层变化规律<br/>Fig.11 Variations of steel corrosion rate with concrete protective layer

图11 钢筋锈蚀率随混凝土保护层变化规律
Fig.11 Variations of steel corrosion rate with concrete protective layer

[1]赵炜,黄巍林,管庭.混凝土冻融损伤对内部钢筋锈蚀影响研究[J].混凝土,2016(6):42-45.
[2]陈际洲,赵铁军,张鹏等.冻融损伤对引气混凝土中钢筋锈蚀的影响研究[J].混凝土与水泥制品,2020,285(1):16-20.
[3]刘继睿,商怀帅,王玮钊,等. 钢筋非均匀锈蚀导致混凝土开裂的研究[J].青岛理工大学学报,2022,43(2):19-27.
[4]LIU Jirui, SHANG Huishuai, WANG Weizhao, et al. Study on concrete cracking caused by non-uniform corrosion of steel bar[J]. Journal of Qingdao University of Technology, 202, 43(2):19-27.
[5]CHEN J, ZHANG W, GU X. Modeling time-dependent circumferential non-uniform corrosion of steel bars in concrete considering corrosion-induced cracking effects[J]. Engineering Structures, 2019, 201: 109766.
[6]李磊,王卓涵,张艺欣,等.钢筋混凝土冻融损伤黏结滑移本构模型及其在构件中的应用[J].建筑结构学报,2021,42(9):213-222.
[7]ZHANG Y, SU R K L. Experimental investigation of the process of corrosion-caused cover cracking[J]. Construction and Building Materials, 2020, 253: 119166.
[8]张菊辉,熊杰.角区钢筋非均匀锈蚀引发混凝土保护层开裂全过程研究[J].上海理工大学学报,2020,42(1):70-78.
[9]王明年,杨恒洪,张艺腾,等.氯盐渗透下钢拱架锈蚀与喷射混凝土间锈胀力研究[J].隧道建设,2022,42(2):224-230.
[10]HE S, CAO Z, LIU W, et al. Experimental study on long-term performance of reinforced concrete beams under a sustained load in a corrosive environment[J]. Construction and Building Materials, 2020, 234: 117288.
[11]ZHANG P, CONG Y, VOGEL M, et al. Steel reinforcement corrosion in concrete under combined actions: The role of freeze-thaw cycles, chloride ingress, and surface impregnation[J]. Construction and Building Materials, 2017, 148: 113-121.
[12]CHEN D, DENG Y, SHEN J, et al. Study on damage rules on concrete under corrosion of freeze-thaw and saline solution[J]. Construction and Building Materials, 2021, 304: 124617.
[13]中华人民共和国住房和城乡建设部.普通混凝土长期性能和耐久性能试验方法:GBJ 82-1985[S]. 北京: 中国建筑工业出版社, 2009.

备注

引言

1 试验概况

2 试验结果分析与讨论

3 结论

期刊信息