硫酸盐腐蚀与冻融共同作用下井壁混凝土损伤劣化研究
Research on Damage and Deterioration of Concrete for Shaft Lining Under Action of Sulfate Corrosion and Freeze-thaw
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摘要: 通过试验研究了初始损伤井壁混凝土随硫酸盐腐蚀和冻融循环次数的增加，其质量、超声波传播速度及强度等的变化，运用损伤力学对损伤进行定量评价和参数拟合并借助环境扫描电镜观测分析混凝土微结构的变化。试验结果表明，随着腐蚀和冻融周期循环次数的增加，混凝土的质量呈先增大后迅速减小，超声波传播速度和抗压强度逐渐减小，初始损伤加剧了混凝土性能的劣化；冻融在混凝土损伤劣化中起主导作用，其引起的破坏作用远大于硫酸盐腐蚀。在冻融因素作用下，初始损伤对混凝土性能劣化的影响明显增强；腐蚀和冻融的叠加作用引起混凝土内部微裂纹的产生和连通，而初始损伤的存在使得微裂纹网络体系更加发达，呈现龟裂状延伸和扩展。Abstract: With the increase of corrosion and freeze-thaw cycles, the changes in the parameters of concrete with initial damage were experimentally studied, including mass, ultrasonic velocity and compressive strength. The quantitative evaluation and parameter fitting was made based on damage mechanical theory. The changes of concrete microstructures were analyzed using the environmental scanning electron microscopy（ＥＳＥＭ）. The research results show that: with the increase of corrosion and freeze-thaw cycles, the mass of concrete increases first and then decreases, and ultrasonic velocity and compressive strength of concrete gradually is reduced. The initial damage exacerbates deterioration of concrete. The action of freeze-thaw plays a leading role in the damage and deterioration of concrete and brings the more and greater destructive effect than corrosion. Under the action of freeze-thaw, the initial damage has an more obvious impact on deterioration of concrete. The action of sulfate attack and freeze-thaw leads to the formation and connection of micro-cracks inside concrete. The existence of initial damage leads to more developed micro-cracks network which extends and expands continuously.
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Keywords:
- initial damage /
- sulfate corrosion /
- freezing-thawing damage /
- damage evolution /
- microstructure /
- concrete /
- shaft lining
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[1] Leemann A, Loser R. Analysis of concrete in a vertical ventilation shaft exposed to sulfate-containing groundwater for 45 years[J]. Cement and Concrete Composites, 2011, 33(1):74-83. [2] 刘娟红,卞立波,何伟,等.煤矿矿井混凝土井壁腐蚀的调查与破坏机理[J].煤炭学报,2015,40(3):528. [3] 高萌,刘娟红,吴爱祥,等.典型氯盐环境中富水充填材料腐蚀及劣化机理[J].中南大学学报(自然科学版),2016,47(8):2776-2783. [4] 刘泉声,黄诗冰,康永水,等.低温饱和岩石未冻水含量与冻胀变形模型研究[J].岩石力学与工程学报,2016,35(10):2000-2012. [5] 丁梧秀,徐桃,王鸿毅,等.水化学溶液及冻融耦合作用下灰岩力学特性试验研究[J].岩石力学与工程学报,2015,34(5):979-985. [6] 赵庆新,李东华,闫国亮,等.受损混凝土抗硫酸盐腐蚀性能[J].硅酸盐学报,2012,40(2):217-220. [7] 闫东明,刘康华,李贺东,等.带初始损伤混凝土的动态抗压性能研究[J].水利学报,2015,46(9):1110. [8] 魏强,谢剑,吴洪海.超低温冻融循环对混凝土材料性能的影响[J].工程力学,2013,30(增刊):125-131. [9] 张峰,蔡建军,李树忱,等.混凝土冻融损伤厚度的超声波检测[J].深圳大学学报(理工版),2012,29(3):207. [10] 祝金鹏,李术才,刘宪波,等.冻融环境下混凝土力学性能退化模型[J].建筑科学与工程学报,2009,26(1):62-67. [11] Pan Feng,Edward J. Garboczi,Changwen Miao,et al. Microstructural origins of cement paste degradation by external sulfate attack[J]. Construction and Building Materials, 2015, 96(15): 391-403. [12] 赵力,刘娟红,周卫金,等.矿井环境中混凝土材料腐蚀损伤演化与机理分析[J].煤炭学报,2016,41(6):1422-1428. [13] 苑立冬,牛荻涛,姜磊,等.硫酸盐侵蚀与冻融循环共同作用下混凝土损伤研究[J].硅酸盐通报,2013,32(6):1171-1176. [14] 张建业,余红发,麻海燕,等.盐腐蚀与应力作用下混凝土的冻融损伤及抑制[J].混凝土,2009(12):32.
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