INFLUENCE OF SELF-HEALING ON CHLORIDE ION INGRESS IN CRACKED CONCRETE
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摘要: 开裂及自愈合是混凝土不可避免的现象。对3种不同水灰比的预制多裂缝试件,进行40d和160d在质量分数为6%的NaCl溶液中的完全浸泡试验,结果表明,裂缝面处出现了不同程度的自愈合,自愈合面积随水灰比减小而增大,随时间增长而逐渐增大,但增大的速度逐渐变小。相同深度处裂缝附近的自由氯离子质量分数随距裂缝距离的增大而减小,且由于自愈合减小了裂缝面处的有效面积,导致氯离子从裂缝面侵入的数量小于从暴露表面侵入的数量。Abstract: Cracking and self-healing are inevitable phenomenon for concrete structures.Three types of concrete specimens with multi-pre-cracks are designed for the test.Then the specimens were exposed to 6% NaCl solution for 40 d and 160 d.At last the self-healing area fraction in cracks' surface and chloride concentration in concrete near cracks were detected by RCT methods.Results show that self-healing area is increased with exposure time and the value of W/C, it decreases the crack surface and chloride ion in the crack, which makes the chloride ion ingress into concrete through crack surface be less than that through exposed surface.
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Key words:
- concrete /
- pre-crack /
- chloride ion /
- self-healing
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? [1] 金伟良,赵羽习.混凝土结构耐久性[M].北京:科学出版社,2002. [2] 王铁梦.工程结构裂缝控制[M].北京:中国建筑工业出版社,1997. [3] Djerbi A, Bonnet S, Khelidj A, et al. Influence of Traversing Crack?on Chloride Diffusion into Concrete[J]. Cement and Concrete?Research,2008,38(6):877-883. [4] Takewaka K, Yamaguchi T, Maeda S. Simulation Model for?Deterioration of Concrete Structures due to Chloride Attack[J]. Journal of Advanced Concrete Technology,2001(2):139-146. [5] Nataliya H. Self-Sealing, Autogenous Healing and Continued?Hydration: What Is the Difference[J]. Materials and Structures,1998,31:563-567. [6] 李佩珍,谢慧才. RCT快速氯离子检测方法及其应用[J].混凝土,2000(12):46-48. [7] Neville A M. Properties of Concrete [M]. London: PrrMAN,1973. [8] Suryavanshi A K. Estimation of Diffusion Coefficients for Chloride?Ion Penetration into Structural Concrete [J]. ACI Materials?Journal,2002,99(5):441-449.
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