高性能复合砂浆对混凝土抗渗及加固性能的研究

发布时间：2018-11-03 10:20

【摘要】：混凝土在目前工程建设中普遍应用,但是由于混凝土本身的材料为非均质且性质较脆,硬化成型后的混凝土存在许多微孔隙,导致其在使用过程中易出现渗水和裂缝等现象,在不同程度上影响了混凝土的耐久性和力学性能。现阶段许多高层建筑外墙及地下工程出现了渗漏的难题,混凝土具有良好的抗渗性能可以保证混凝土建筑物的安全性、节约混凝土建筑物的维护及修复成本、延长混凝土建筑物的使用寿命及改善我们的生活及居住环境条件。抗渗难题也一直受到学术界及工程界的高度重视,但取得的效果甚微。另外随着建筑结构的使用年限增加,我国面临着较多老旧建筑加固修复的问题。对结构进行加固,不但可以维持结构正常使用功能,延长结构的使用寿命,而且也可为国家节约资金。混凝土结构的加固方法有很多,常用的有外包刚加固法、加大截面加固法、预应力加固法、粘贴钢板加固法及增设支点加固法,但是这些加固方法都有一些明显的不足。现在的加固材料多为有机材料,有机材料耐火性能及抗老化性能较差,且不利于环保,而抗渗性能优异的无机材料不但可以解决以上有机材料存在的材料弊端,而且与混凝土材料非常接近,不会形成材质彼此不相容的隔离层,在加固后无机材料与原构件之间有更好的相容性及工作协调性。采用无机材料加固能够较好的解决加固工程中的耐久性问题。本文首先分析影响混凝土抗渗性能的主要因素,了解混凝土渗透的机理,为后续试验研究找到可行的解决问题的突破口,并利用抗渗仪采用水压力法中的抗渗标号法进行试验研究。了解传统提高混凝土抗渗性能的方法,与传统提高混凝土抗渗方法比较,说明本研究的优势之处。并简要介绍高性能复合砂浆钢筋网薄层对同时具有抗渗及加固需求的工程意义之处。试验分别对素混凝土试块、未掺加添加剂的水泥砂浆涂抹在混凝土迎水面的试块及掺加新型添加剂的复合砂浆涂抹在混凝土迎水面的试块进行抗渗试验,并改变砂浆的涂抹厚度及添加剂的掺入量,分析试验所得数据。研究结果表明:掺加特殊新型添加剂的高性能复合砂浆涂抹在混凝土表面可有效提高混凝土的抗渗性能。且此高性能复合砂浆与钢筋网形成加固薄层能有效的对结构进行加固,对混凝土抗渗性能及结构加固方法的研究具有重要意义。
[Abstract]:Concrete is widely used in engineering construction at present. However, because the material of concrete itself is heterogeneous and brittle, there are many micro-pores in the concrete after hardening and forming, which leads to water seepage and cracks in the process of use. The durability and mechanical properties of concrete are affected to some extent. At the present stage, many high-rise building exterior walls and underground projects have the problem of leakage. The good impermeability of concrete can ensure the safety of concrete buildings and save the maintenance and repair cost of concrete buildings. Extend the service life of concrete buildings and improve our living and living environment. The problem of impermeability has always been attached great importance by the academic and engineering circles, but the effect has been very little. In addition, with the increase of the service life of the building structure, our country is faced with many problems of strengthening and repairing old and old buildings. Strengthening the structure can not only maintain the normal function of the structure and prolong the service life of the structure, but also save money for the country. There are many reinforcement methods for concrete structures, such as the external reinforcement method, the reinforcement method of increasing section, the method of prestress strengthening, the method of sticking steel plate and the method of adding the support point, but these methods have some obvious shortcomings. At present, most of the reinforcement materials are organic materials. The refractory and anti-aging properties of organic materials are poor, and they are not conducive to environmental protection. The inorganic materials with excellent impermeability can not only solve the disadvantages of the above organic materials, Moreover, it is very close to the concrete material, and will not form a mutually incompatible isolation layer, which has better compatibility and work coordination between the inorganic materials and the original members after strengthening. Using inorganic material to reinforce can solve the durability problem in reinforcement engineering. In this paper, the main factors affecting the impermeability of concrete are analyzed, and the mechanism of concrete permeation is understood. The anti-seepage mark method of water pressure method was used to test the anti-seepage meter. To understand the traditional methods to improve the impermeability of concrete, compare with the traditional methods of improving the impermeability of concrete, and explain the advantages of this study. This paper also briefly introduces the engineering significance of high performance composite mortar steel mesh thin layer for both impermeability and reinforcement. The impermeability tests were carried out on the plain concrete test blocks, the cement mortar without additives applied on the concrete water surface and the composite mortar smeared with new additives on the concrete water surface, respectively. The thickness of mortar smear and the amount of additives are changed, and the experimental data are analyzed. The results show that the high performance composite mortar smeared on the surface of concrete with special new additives can effectively improve the impermeability of concrete. The high performance composite mortar and reinforcement mesh can effectively strengthen the structure, which is of great significance to the study of the impermeability of concrete and the method of strengthening the structure.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU746.3;TU578.1

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