为探明青海地区盐沼泽环境下混凝土的腐蚀情况,在该地区展开现场腐蚀试验,考虑混凝土不同埋置工况,观察其微观结构,并结合混凝土质量损失、抗侵蚀系数变化以及钢筋锈蚀率变化评价混凝土耐久性。试验结果表明:混凝土质量变化不能作为评价指标来描述混凝土的损伤破坏;对于放置在地面和埋置在水中的混凝土,当混凝土内掺有水泥基时,其抗侵蚀系数最高,而在埋深1.25 m工况下掺有粉煤灰-硅灰的混凝土抗侵蚀能力最强;混凝土的劣化是膨胀力、冻结应力、结晶应力等多重因素共同作用下的结果;放置在地面的混凝土锈蚀率最高,尤其是单掺水泥基的钢筋混凝土锈蚀率最高,而复掺粉煤灰-水泥基的混凝土锈蚀率最低。
Abstract
Field corrosion tests were conducted in salt swamp environments in Qinghai Province to investigate the corrosion of concrete in the region. The microstructure of concrete was observed under different burial conditions, and the durability of concrete was evaluated by assessing the mass loss, changes in anti-corrosion coefficient, and changes in corrosion rate of steel bars. Results indicate that changes in the mass of concrete can not be used as an evaluation index to describe concrete damage. Embedded in the ground or water, concrete mixed with cement-based materials exhibits the highest corrosion resistance coefficient, while concrete mixed with fly ash-silica fume has the highest corrosion resistance when buried at a depth of 1.25 m. Concrete deterioration results from multiple factors such as expansion force, freezing stress, and crystallization stress. The corrosion rate of concrete embedded in the ground, particularly reinforced concrete mixed merely with cement base, is the highest. The corrosion rate of concrete with fly ash-cement base is the lowest.
关键词
混凝土 /
耐久性 /
盐沼泽 /
腐蚀试验
Key words
concrete /
durability /
salt swamp /
corrosion test
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 冯忠居, 郭穗柱, 孟莹莹, 等. 盐沼泽区冻融作用下桥梁桩基腐蚀损伤模拟试验[J]. 哈尔滨工业大学学报, 2021, 53(9): 69-78.
[2] 冯忠居, 霍建维, 胡海波, 等. 高寒盐沼泽区干湿-冻融循环下桥梁桩基腐蚀损伤与承载特性[J]. 交通运输工程学报, 2020, 20(6): 135-147.
[3] 冯忠居, 李 铁, 冯 凯, 等. 基于Mohr-Coulomb的强盐沼泽区桩基承载特性探讨[J]. 长江科学院院报, 2020, 37(11): 74-80.
[4] 冯忠居, 胡海波, 王富春, 等. 高海拔强盐沼泽区桥梁桩基损伤现场模拟试验[J]. 交通运输工程学报, 2019, 19(3): 46-57.
[5] 冯忠居, 陈思晓, 徐 浩, 等. 基于灰色系统理论的高寒盐沼泽区混凝土耐久性评估[J]. 交通运输工程学报, 2018, 18(6): 18-26.
[6] 姚贤华, 冯忠居, 王富春, 等. 盐沼泽环境下公路桥梁桩基材料耐腐蚀试验[J]. 长安大学学报(自然科学版), 2018, 38(1): 49-58.
[7] 姚贤华, 冯忠居, 王富春, 等. 复合盐浸下多元外掺剂-混凝土抗干湿-冻融循环性能[J]. 复合材料学报, 2018, 35(3): 690-698.
[8] CHEN J K, JIANG M Q, ZHU J. Damage Evolution in Cement Mortar Due to Erosion of Sulphate[J]. Corrosion Science, 2008, 50(9): 2478-2483.
[9] COLLEPARDI M. A State-of-the-Art Review on Delayed Ettringite Attack on Concrete[J]. Cement and Concrete Composites, 2003, 25(4/5): 401-407.
[10] GOLLOP R S, TAYLOR H F W. Microstructural and Microanalytical Studies of Sulfate Attack. IV. Reactions of a Slag Cement Paste with Sodium and Magnesium Sulfate Solutions[J]. Cement and Concrete Research, 1996, 26(7): 1013-1028.
[11] GOLLOP R S, TAYLOR H F W. Microstructural and Microanalytical Studies of Sulfate Attack III. Sulfate-Resisting Portland Cement: Reactions with Sodium and Magnesium Sulfate Solutions[J]. Cement and Concrete Research, 1995, 25(7): 1581-1590.
[12] AL-AMOUDI O S B, MASLEHUDDIN M, ABDUL-AL Y A B. Role of Chloride Ions on Expansion and Strength Reduction in Plain and Blended Cements in Sulfate Environments[J]. Construction and Building Materials, 1995, 9(1): 25-33.
[13] 陈晓斌, 唐孟雄, 马昆林. 地下混凝土结构硫酸盐及氯盐侵蚀的耐久性实验[J]. 中南大学学报(自然科学版), 2012, 43(7): 2803-2812.
[14] MAES M, DE BELIE N. Resistance of Concrete and Mortar Against Combined Attack of Chloride and Sodium Sulphate[J]. Cement and Concrete Composites, 2014, 53: 59-72.
[15] DU J, TANG Z, LI G, et al. Key Inhibitory Mechanism of External Chloride Ions on Concrete Sulfate Attack[J]. Construction and Building Materials, 2019, 225: 611-619.
[16] MONTEIRO P J M, KURTIS K E. Time to Failure for Concrete Exposed to Severe Sulfate Attack[J]. Cement and Concrete Research, 2003, 33(7): 987-993.
[17] MA H, GONG W, YU H, et al. Durability of Concrete Subjected to Dry-Wet Cycles in Various Types of Salt Lake Brines[J]. Construction and Building Materials, 2018, 193: 286-294.
[18] MELCHERS R E, CHAVES I A. Durability of Reinforced Concrete Bridges in Marine Environments[J]. Structure and Infrastructure Engineering, 2020, 16(1): 169-180.
[19] 李 耀, 尹世平, 吕恒林. 氯盐干湿循环下纤维编织网增强混凝土与既有混凝土的界面性能[J]. Journal of Central South University, 2020, 27(3): 876-890.
[20] YU Y L, YIN S P, NA M W. Bending Performance of TRC-Strengthened RC Beams with Secondary Load under Chloride Erosion[J]. Journal of Central South University, 2019, 26(1): 196-206.
[21] 孔元元. 镇赉盐渍土冻融条件下水热盐运移试验及结构演变研究[D]. 长春: 吉林大学, 2017.
[22] 徐善华. 混凝土结构退化模型与耐久性评估[D]. 西安: 西安建筑科技大学, 2003.
[23] 于继寿, 殷国伟, 葛 勇, 等. 掺合料对钢筋锈蚀性能的影响[J]. 武汉理工大学学报, 2009, 31(2): 82-86.
[24] 洪乃丰. 混凝土中钢筋腐蚀与防护技术(6): 钢筋阻锈剂和阴极保护[J]. 工业建筑, 2000, 30(1): 57-60.
基金
国家自然科学基金项目(41907236);青海省交通科技攻关项目(2014-07)
PDF(5725 KB)
