Study on the deterioration patterns of reinforced concrete under full immersion environment in subtropical ocean
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摘要:
针对亚热带海洋环境混凝土中钢筋锈蚀问题，通过模拟亚热带海洋环境，对不同强度等级和阻锈剂掺量的钢筋混凝土试件进行全浸泡侵蚀试验，利用电化学无损检测、氯离子含量测试，结合微观检测分析了钢筋混凝土的腐蚀劣化规律。研究结果表明：混凝土强度等级的提高和阻锈剂掺量的增加均能明显提升钢筋混凝土的耐腐蚀性能。其中，C30混凝土抗锈蚀性能最差，120 d时，腐蚀电流密度为0.118 μA/cm2，极化电阻为220 kΩ·cm2，混凝土电阻为87.3 kΩ·cm2，钢筋-混凝土界面区转移电阻为77.3 kΩ·cm2，达到脱钝状态；混凝土强度等级提高至C50时，腐蚀电流密度减小了58.47%，极化电阻增加了3.82倍，混凝土电阻增加了44.56%；阻锈剂掺量为6 kg/m3时，腐蚀电流密度减小了47.45%，极化电阻增加了2.81倍，钢筋-混凝土界面区转移电阻增加了72.43%。
Abstract:Aiming at the corrosion problem of steel bars in concrete in subtropical marine environment, the full immersion corrosion experiments of reinforced concrete specimens with different strength grades and rust inhibitor contents were carried out by simulating the subtropical marine environment.The macroscopic indexes such as chloride ion content were tested by electrochemical non-destructive testing, and the experimental results were verified by microscopic detection methods.The corrosion degradation patterns of reinforced concrete was analyzed.The results show that the improvement of concrete strength grade and the increase of rust inhibitor content can significantly improve the corrosion resistance of reinforced concrete.Among them, the corrosion resistance of C30 concrete is the worst.At 120 d, the corrosion current density is 0.118 μA/cm2, the polarization resistance is 220 kΩ cm2, the concrete resistance is 87.3 kΩ cm2, and the transfer resistance of the steel-concrete interface area is 77.3 kΩ cm2, reaching the passivation state.When the concrete strength grade is increased to C50, the corrosion current density is reduced by 58.47%, the polarization resistance is increased by 3.82 times, and the concrete resistance is increased by 44.56%;when the amount of rust inhibitors is 6 kg/m3, the corrosion current density is reduced by 47.45%, the polarization resistance is increased by 2.81 times, and the transfer resistance at the reinforcement-concrete interface is increased by 72.43%.
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图 2 不同强度混凝土中钢筋极化电阻和腐蚀电流密度随浸泡龄期变化
Figure 2. The polarization resistance and corrosion current density of steel bars in concrete with different strength change with soaking age
图 3 不同阻锈剂掺量混凝土中钢筋极化电阻和腐蚀电流密度随浸泡龄期变化
Figure 3. The polarization resistance and corrosion current density of steel bar in concrete with different corrosion inhibitor content change with soaking age
图 5 不同强度等级的混凝土电阻随浸泡龄期变化
Figure 5. The resistance of concrete with different strength grades changes with soaking age
图 6 不同阻锈剂掺量的钢筋-混凝土界面区转移电阻随浸泡龄期变化
Figure 6. The change of transfer resistance of steel-concrete interface area with different content of rust inhibitor with soaking age
图 7 S1和SZ1混凝土中不同深度氯离子含量(占混凝土质量%)
Figure 7. Change of chloride ion content at different depths in S1 and SZ1 concrete (% of concrete mass)
图 8 S1和SZ1混凝土中不同深度pH值随浸泡龄期变化
Figure 8. The change of pH value at different depths in S1 and SZ1 concrete with soaking age
图 9 不同龄期混凝土表层物质XRD图谱
Figure 9. XRD analysis results of surface material of concrete at different ages
图 10 浸泡前后不同强度等级混凝土核磁共振T2谱分布曲线
Figure 10. The distribution curve of nuclear magnetic resonance T2 spectrum of concrete with different strength before and after soaking
图 11 浸泡前后不同强度混凝土的各类孔径分布
Figure 11. The pore size distribution of concrete with different strength before and after soaking
图 14 钢筋表面氯离子腐蚀后XPS测试
Figure 14. XPS test after chloride ion corrosion on the surface of steel bar
表 1 胶凝材料化学组分质量分数
Table 1. Chemical composition of cementitious materials
% 材料 w烧失量 w(SiO2) w(Al2O3) w(Fe2O3) w(CaO) w(MgO) w(SO3) C 1.62 26.4 9.6 4.3 50.1 3.2 2.0 FA 5.4 44.4 25.1 12.6 11.9 0.8 1.8 
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表 2 混凝土配合比
Table 2. Concrete mix proportion
编号 配合比/(kg·m-3) W/C C W S R FA WR N S1 250 165 701.10 1 143.90 100 3.5 0 0.47 S2 320 160 712.00 1 068.00 100 4.2 0 0.38 S3 380 156 715.56 1 028.40 100 4.8 0 0.33 SZ1 250 165 701.10 1 143.90 100 3.5 2 0.47 SZ2 250 165 701.10 1 143.90 100 3.5 4 0.47 SZ3 250 165 701.10 1 143.90 100 3.5 6 0.47
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表 3 浸泡前后不同强度混凝土核磁共振T2谱积分面积
Table 3. Integral area of nuclear magnetic resonance T2 spectrum of concrete with different strength before and after soaking
组别 T2谱总积分面积 第一峰 第二峰 第三峰 积分面积 比例/% 积分面积 比例/% 积分面积 比例/% 侵蚀前 S1 423.470 287.970 68.04 84.448 19.94 51.052 12.06 S2 346.104 234.618 67.79 76.228 22.02 35.258 10.19 S3 262.545 172.803 65.82 66.970 25.51 22.771 8.67 侵蚀180 d后 S1 377.090 311.350 82.59 38.240 10.14 27.500 7.27 S2 326.311 271.467 82.89 31.923 9.93 22.921 12.14 S3 237.943 192.585 80.94 28.891 7.18 16.467 6.92
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[1] HOU B R, LI X G, MA X M, et al. The cost of corrosion in China[J]. NPJ Materials Degradation, 2017, 1: 4. doi: 10.1038/s41529-017-0005-2 [2] BAO J W, WEI J N, ZHANG P, et al. Experimental and theoretical investigation of chloride ingress into concrete exposed to real marine environment[J]. Cement and Concrete Composites, 2022, 130: 104511. doi: 10.1016/j.cemconcomp.2022.104511 [3] LIU Q C, SUN L F, ZHU X J, et al. Chloride transport in the reinforced concrete column under the marine environment: Distinguish the atmospheric, tidal-splash and submerged zones[J]. Structures, 2022, 39: 365-377. doi: 10.1016/j.istruc.2022.03.041 [4] ZHAO Y X, XU X Y, WANG Y Z, et al. Characteristics of pitting corrosion in an existing reinforced concrete beam exposed to marine environment[J]. Construction and Building Materials, 2020, 234: 117392. doi: 10.1016/j.conbuildmat.2019.117392 [5] ZHAO J F, LIN Y, LI X, et al. Experimental study on the cyclic behavior of reinforced concrete bridge piers with non-uniform corrosion[J]. Structures, 2021, 33: 999-1006. doi: 10.1016/j.istruc.2021.04.060 [6] YI Y, ZHU D, GUO S, et al. A review on the deterioration and approaches to enhance the durability of concrete in the marine environment[J]. Cement and Concrete Composites, 2020, 113: 103695. doi: 10.1016/j.cemconcomp.2020.103695 [7] 刘勇. 氯盐侵蚀对混凝土微观结构损伤的影响研究[J]. 西安建筑科技大学学报: 自然科学版, 2020, 52(3): 390-395. https://www.cnki.com.cn/Article/CJFDTOTAL-XAJZ202003012.htmLIU Yong. Study on the damage characteristics of concrete structures by chloride erosion[J]. Journal of Xi'an University of Architecture & Technology: Natural Science Edition, 2020, 52(3): 390-395. https://www.cnki.com.cn/Article/CJFDTOTAL-XAJZ202003012.htm [8] 周金枝, 付甜甜, 双子洋, 等. 氯盐浸泡下再生混凝土力学性能试验研究[J]. 工业建筑, 2023, 53(6): 187-193. https://www.cnki.com.cn/Article/CJFDTOTAL-GYJZ202306025.htmZHOU Jinzhi, FU Tiantian, SHUANG Ziyang, et al. Experimental research on mechanical properties of recycled concrete immersed in chloride solution[J]. Industrial Construction, 2023, 53(6): 187-193. https://www.cnki.com.cn/Article/CJFDTOTAL-GYJZ202306025.htm [9] 刘克, 张杰, 李焰, 等. 钢筋混凝土实际海洋环境下的腐蚀[J]. 装备环境工程, 2020, 17(4): 96-104. https://www.cnki.com.cn/Article/CJFDTOTAL-JSCX202004017.htmLIU Ke, ZHANG Jie, LI Yan, et al. Corrosion of reinforced concrete in marine environment[J]. Equipment Environmental Engineering, 2020, 17(4): 96-104. https://www.cnki.com.cn/Article/CJFDTOTAL-JSCX202004017.htm [10] 金祖权, 孙伟, 张云升, 等. 混凝土在硫酸盐、氯盐溶液中的损伤过程[J]. 硅酸盐学报, 2006, 34(5): 630-635. doi: 10.3321/j.issn:0454-5648.2006.05.025JIN Zuquan, SUN Wei, ZHANG Yunsheng, et al. Damage of concrete in sulfate and chloride solution[J]. Journal of the Chinese Ceramic Society, 2006, 34(5): 630-635. doi: 10.3321/j.issn:0454-5648.2006.05.025 [11] JIN Z Q, ZHAO X, ZHAO T J, et al. Chloride ions transportation behavior and binding capacity of concrete exposed to different marine corrosion zones[J]. Construction and Building Materials, 2018, 177: 170-183. doi: 10.1016/j.conbuildmat.2018.05.120 [12] LIN G, LIU Y H, XIANG Z H. Numerical modeling for predicting service life of reinforced concrete structures exposed to chloride environments[J]. Cement and Concrete Composites, 2010, 32(8): 571-579. doi: 10.1016/j.cemconcomp.2010.07.012 [13] ZHAO H R. Design of concrete building structure in marine corrosion zones[J]. Journal of Coastal Research, 2020, 110(S1): 266-270. [14] CHEN X D, MING Y, FU F, et al. Numerical and empirical models for service life assessment of RC structures in marine environment[J]. International Journal of Concrete Structures and Materials, 2022, 16(1): 11. doi: 10.1186/s40069-022-00504-0 [15] 乔宏霞, 杨振清, 王鹏辉, 等. 利用Wiener过程探究镁水泥混凝土中涂层钢筋在盐类环境下的腐蚀寿命[J]. 建筑材料学报, 2021, 24(5): 986-993. doi: 10.3969/j.issn.1007-9629.2021.05.012QIAO Hongxia, YANG Zhenqing, WANG Penghui, et al. Corrosion life investigation of coated steel bars in magnesium cement concrete under salt solution environment using Wiener process[J]. Journal of Building Materials, 2021, 24(5): 986-993. doi: 10.3969/j.issn.1007-9629.2021.05.012 [16] 付前旺. 非饱和风积沙混凝土水分与氯离子传输行为[D]. 包头: 内蒙古科技大学, 2022.FU Qianwang. Investigation of moisture and chloride ion transport behavior of unsaturated aeolian sand concrete[D]. Baotou: Inner Mongolia University of Science & Technology, 2022. [17] 刘波, 高荣, 何艳清, 等. 冻融作用下水泥改良土未冻水含量及孔隙特征试验研究[J]. 矿业科学学报, 2023, 8(6): 791-802. doi: 10.19606/j.cnki.jmst.2023.06.006LIU Bo, GAO Rong, HE Yanqing, et al. Experiment research on unfrozen water content and pore characteristic of cement improved soil under freeze-thaw cycle[J]. Journal of Mining Science and Technology, 2023, 8(6): 791-802. doi: 10.19606/j.cnki.jmst.2023.06.006 [18] 朱海威, 余红发, 麻海燕. 阻锈剂对海洋环境下混凝土中钢筋腐蚀影响的电化学研究[J]. 东南大学学报: 自然科学版, 2020, 50(1): 109-119. https://www.cnki.com.cn/Article/CJFDTOTAL-DNDX202001015.htmZHU Haiwei, YU Hongfa, MA Haiyan. Electrochemical study on effect of rust inhibitors on corrosion of reinforcing bar in concrete in marine environment[J]. Journal of Southeast University: Natural Science Edition, 2020, 50(1): 109-119. https://www.cnki.com.cn/Article/CJFDTOTAL-DNDX202001015.htm [19] 刘国建. 严酷复合介质侵蚀下混凝土中钢筋腐蚀行为及机理[D]. 南京: 东南大学, 2019.LIU Guojian. Corrosion behavior and mechanism of reinforcing steel under severe composite corrosive medium[D]. Nanjing: Southeast University, 2019. [20] HAYCOCK E W. Discussion of "electrochemical polarization, 1. A theoretical analysis of the shape of polarization curves"[M. stern and A.L. geary (pp. 56-63, vol. 104)[J]. Journal of the Electrochemical Society, 1957, 104(12): 751. [21] ALONSO C, ANDRADE C, CASTELLOTE M, et al. Chloride threshold values to depassivate reinforcing bars embedded in a standardized OPC mortar[J]. Cement and Concrete Research, 2000, 30(7): 1047-1055. doi: 10.1016/S0008-8846(00)00265-9 [22] 陈明实. 钢筋阻锈剂作用机理及效果研究[D]. 包头: 内蒙古科技大学, 2015.CHEN Mingshi. Research on mechanism and effect of rust inhibitor[D]. Baotou: Inner Mongolia University of Science & Technology, 2015. [23] 马世豪. 海洋钢筋混凝土结构内掺型阻锈剂阻锈性能研究[D]. 青岛: 青岛理工大学, 2016.MA Shihao. Study on the performance of admixed corrosion inhibitor in marine reinforced concrete structure[D]. Qingdao: Qingdao University of Technology, 2016. [24] WU Z W, Lian H Z. High performance concrete[M]. Beijing: China Railway Publishing House, 1999: 42-43. [25] 冯琼. 西部盐渍土地区钢筋混凝土耐久性试验研究及寿命预测[D]. 兰州: 兰州理工大学, 2019.FENG Qiong. Experimental study and life prediction of reinforced concrete in Western China's saline soil area[D]. Lanzhou: Lanzhou University of Technology, 2019. [26] 张杰. 海洋环境下混凝土的氯离子传输模型研究[D]. 天津: 天津大学, 2014.ZHANG Jie. Study on transmission model of chloride ions in concrete under marine environment[D]. Tianjin: Tianjin University, 2014. [27] 邓拓. 钢筋锈蚀对混凝土结构耐久性的影响及其评估[D]. 长沙: 长沙理工大学, 2012.DENG Tuo. The effect and evaluation of reinforcement corrosion on durability of concrete Structure[D]. Changsha: Changsha University of Science & Technology, 2012. [28] 马志超. 混凝土钢筋腐蚀的电化学研究[D]. 长沙: 长沙理工大学, 2012.MA Zhichao. Research on the electrochemical mechanism of concrete steel corrosion[D]. Changsha: Changsha University of Science & Technology, 2012. [29] GARDIN E, ZANNA S, SEYEUX A, et al. Comparative study of the surface oxide films on lean duplex and corresponding single phase stainless steels by XPS and ToF-SIMS[J]. Corrosion Science, 2018, 143: 403-413. -
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