动水下混凝土裂缝用水泥基灌浆材料研究

发布时间：2018-07-09 20:51

本文选题：灌浆修补 + 水下混凝土裂缝　；参考：《重庆大学》2014年硕士论文

【摘要】：混凝土材料因自身抗拉强度低，温差，收缩，碱集料反应等等原因，在生产和使用过程中很容易产生裂缝。一旦产生裂缝，在影响外观同时，如果裂缝过大将对结构的安全性造成损害。灌浆法作为一种全面修复技术，其先进修补的原理和优异的效果使其成为了国内外混凝土裂缝修补的重要手段。但是对于水下混凝土裂缝，因自身的饱水环境，要求灌浆材料具备水下抗分散等性能，这使的普通的水泥基灌浆材料遇到了瓶颈。本文以水下混凝土和水下砂浆为基础，使用我国常用的聚丙烯酰胺类和纤维素类两种絮凝剂，根据水下裂缝特殊环境的要求，配制能在动水情况下使用的水泥基灌浆材料，并在实验室模拟动水情况下的裂缝灌浆。通过对此种类型水泥基灌浆材料的研究，为实际工程的水下混凝土裂缝灌浆提供参考。试验结果表明： ①聚丙烯酰胺和羟丙基甲基纤维素两类絮凝剂，通过架桥作用和电荷中和作用能使水泥浆液达到水下不分散的性能； ②聚丙烯酰胺类絮凝剂加入水泥浆液后，浆液的流动度将整体出现减小，但随其掺量的增大，浆液流动度出现先增大后减小的变化，，出现“临界点”。分子量越大的聚丙烯酰胺抗分散作用越强，但是对浆液的流动度越不利； ③羟丙基甲基纤维素同样会导致水泥浆流动度减小，同时自身具有引气作用，导致浆体硬化后内外产生大量孔洞，降低强度。浆液碱（NaOH）含量的增加将破坏此类絮凝剂抗分散效果； ④最终水泥基灌浆材料Z组配合比具有流动性大，动水不分散，能很好的填充宽大的裂缝，达到理想的修补效果，最后形成的灌注体具备较高的早期和后期强度。
[Abstract]:Because of its low tensile strength, temperature difference, shrinkage, alkali aggregate reaction and other reasons, concrete materials are easy to produce cracks in the process of production and use. Once a crack is produced, the safety of the structure will be damaged if the crack is too large at the same time as affecting the appearance. Grouting as a comprehensive repair technology, its advanced repair principle and excellent effect make it become an important means of repairing concrete cracks at home and abroad. However, for underwater concrete cracks, due to their saturated water environment, grouting materials are required to have underwater anti-dispersion and other properties, which makes the common cement-based grouting materials meet the bottleneck. Based on underwater concrete and underwater mortar, two kinds of flocculants, polyacrylamide and cellulose, which are commonly used in China, are used in this paper. According to the special environment requirements of underwater cracks, cement based grouting materials which can be used in dynamic conditions are prepared. The crack grouting is simulated in the laboratory under the condition of dynamic water. Through the study of this kind of cement-based grouting material, this paper provides a reference for underwater concrete crack grouting. The results show that: (1) two kinds of flocculants, polyacrylamide and hydroxypropyl methyl cellulose, can make the cement slurry underwater non-dispersible by bridging action and charge neutralization action; (2) when the polyacrylamide flocculant is added into the cement slurry, the fluidity of the slurry will decrease as a whole, but with the increase of its content, the fluidity of the slurry will increase first and then decrease, and the "critical point" will appear. The larger the molecular weight of polyacrylamide is, the stronger the anti-dispersion effect is, but the more unfavorable to the flow degree of the slurry, 3 hydroxypropyl methyl cellulose also leads to a decrease in the fluidity of the cement slurry, and it also has an air entraining effect on itself. After hardening, a large number of holes are produced inside and outside of the slurry, and the strength is reduced. The increase of sodium hydroxide (NaOH) content will destroy the anti-dispersion effect of this kind of flocculant. To achieve the ideal repair effect, the resulting perfusion has high early and late strength.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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