寒冷地区混凝土路面大裂缝修复用自密实混凝土性能研究

发布时间：2018-05-21 12:34

本文选题：自密实混凝土 + 聚合物　；参考：《重庆交通大学》2014年硕士论文

【摘要】：在行车荷载和自然因素的综合作用下,寒冷地区水泥混凝土路面容易破坏,其中裂缝是主要的破坏形式之一。为了延长路面寿命,需对裂缝及时进行有效修补处理。目前路面裂缝修补多采用沥青或环氧树脂等材料,但这类材料存在造价高,易老化、不环保等缺陷。本文结合寒冷地区气候特点,提出采用聚合物改性自密实混凝土对宽度大于15mm的混凝土路面裂缝进行修补。旨在开发出一种施工方便、造价低廉、环保、工作性能好的混凝土裂缝修补材料。采用固定砂石体积法设计自密实混凝土的配合比,分析了水胶比、胶凝材料总量、粉煤灰掺量、砂率等参数对自密实混凝土性能的影响规律。在此基础上,采用丁苯乳液和苯丙乳液两种聚合物分别对自密实混凝土进行改性,对聚灰比分别为1%,3%,5%,8%,10%,15%的自密实混凝土工作性、力学性能、粘结性、耐久性进行了试验研究。最后用扫描电镜试验分析了聚合物的加入对自密实混凝土微观结构的影响。试验结果表明,水胶比为0.41,胶凝材料总量为460kg/m3,粉煤灰掺量为30%,砂率为49%的自密实混凝土拌和物工作性最佳,且粗集料形状指数越大工作性越好。聚合物掺入可以改善了自密实混凝土的柔韧性,增加了界面粘结性能,提高了耐久性。微观结构表明,聚合物加入后形成连续的聚合膜,细化了孔隙,形成密实空间丝网状骨架结构,从而改善了自密实混凝土的宏观性能。综合分析,丁苯乳液聚灰比为10%的自密实混凝土作为裂缝修补材料效果较佳,丁苯乳液聚合物改性自密实混凝土适用于寒冷地区农村公路水泥混凝土路面的大裂缝修补。
[Abstract]:Under the combined action of driving load and natural factors, cement concrete pavement in cold area is easy to destroy, among which crack is one of the main failure forms. In order to prolong the pavement life, it is necessary to repair the cracks in time. At present, asphalt or epoxy resin are used to repair the pavement cracks, but these materials have the defects of high cost, easy aging and not environmental protection. Based on the climatic characteristics of cold regions, this paper proposes that polymer modified self-compacting concrete can be used to repair cracks of concrete pavement whose width is larger than 15mm. The aim is to develop a kind of concrete crack repair material which is easy to construct, low cost, environmental protection and good working performance. The mixing ratio of self-compacting concrete was designed by the method of fixed sand volume, and the influence of water binder ratio, total amount of cementing material, fly ash content and sand ratio on the performance of self-compacting concrete was analyzed. On this basis, the self-compacting concrete was modified by styrene butadiene emulsion and styrene-acrylic emulsion respectively, and the workability, mechanical properties, adhesive property and durability of self-compacting concrete with the ratio of 1 to 3 and 10 to 15% were studied. Finally, the effect of polymer addition on the microstructure of self-compacting concrete was analyzed by SEM. The experimental results show that the self-compacting concrete with water / binder ratio of 0.41, total amount of cementitious material of 460kg / m3, fly ash content of 30, sand ratio of 49% is the best, and the greater the shape index of coarse aggregate is, the better the workability is. The admixture of polymer can improve the flexibility of self-compacting concrete, increase the interfacial bond property and improve the durability of self-compacting concrete. The microstructure shows that continuous polymeric film is formed after the addition of polymer, which refines the pores and forms a dense space filamentous skeleton structure, thus improving the macroscopic properties of self-compacting concrete. Comprehensive analysis shows that the self-compacting concrete with 10% ratio of polybutylbenzene emulsion to cement is a better material for repairing cracks, and the self-compacting concrete modified by styrene butadiene emulsion is suitable for repairing the large crack of the road cement concrete pavement in the cold area.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414

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