有机成膜涂层混凝土抗氯盐性能的时变退化

发布时间：2018-06-28 00:18

本文选题：混凝土 + 有机成膜涂层　；参考：《中国矿业大学》2017年硕士论文

【摘要】：氯离子侵蚀作为混凝土结构发生破坏最常见的原因之一,严重威胁了混凝土结构的使用,如何阻止氯离子侵蚀混凝土结构,保证结构的使用寿命,成为当前建筑界的一大重要课题。本文以有机成膜涂层混凝土为研究对象,通过研究环氧树脂面漆、氯化橡胶面漆、聚氨酯面漆结合环氧富锌底漆、环氧云铁中间漆构成不同的涂层涂刷体系与不同的水灰比结合后的混凝土的不同老化条件的抗氯盐侵蚀性能以及涂层老化后的微观形貌,得到有机成膜涂层不同老化阶段抗氯盐侵蚀能力同涂层的宏微观性能退化之间的规律,建立基于自然气候条件以及海滨气候条件的有机成膜涂层使用预计模型,取得的主要研究结果与结论如下:1、通过对老化前涂层混凝土的电通量实验研究,获得了不同涂层体系的抗氯离子防护能力。涂刷一遍面漆:聚氨酯环氧树脂氯化橡胶。按体系涂刷:聚氨酯氯化橡胶环氧树脂。增加涂刷底漆等,可以提高涂层混凝土的抗氯离子侵蚀能力。考虑成本,最优的涂层体系为一遍底漆+一遍聚氨酯面漆。采用表面敷设有机涂层措施提高混凝土耐久性时,需考虑混凝土自身抗氯离子扩散性能的影响。2、通过对老化后涂层混凝土的电通量实验研究:发现环氧树脂涂层体系紫外老化后,混凝土的电通量值随老化时间在逐渐增大,混凝土电通量随环氧树脂涂层体系厚度的增加在呈指数型函数降低;自然大气暴露条件和自然海滨暴露条件下,各种涂层体系对混凝土的防护效果均为:聚氨酯氯化橡胶环氧树脂,且漆膜越厚,涂层的防护效果越好。电通量实验作为实验室加速测定混凝土抗氯离子渗透性能的方法与实际环境氯离子侵蚀有很好的对应性,可以相对真实地反映涂层对混凝土的防护效果。3、根据实验数据,回归分析了混凝土电通量与老化时间的函数关系,找到了预测不同涂层体系厚度在不同使用地区的寿命预测方法。相对于自然大气老化,紫外老化的平均加速效应约为13.31倍,海滨暴露老化的平均加速效应约为1.667倍。对涂层老化前后宏观变化程度和微观形貌的分析发现:有机成膜涂层的抗氯离子防护能力随着涂层老化的衰减原因在于涂层降解腐蚀造成了缺陷的产生以及发展。4、根据涂层使用寿命以及涂层体系的花费,得到各涂层体系的年平均花费,其中底漆+中漆+2遍聚氨酯面漆涂层体系的年平均花费最低,在不考虑人工成本的前提下,此涂刷体系最为经济。
[Abstract]:Chloride ion erosion is one of the most common causes of concrete structure damage, which seriously threatens the use of concrete structure. How to prevent chloride ion from eroding concrete structure and ensure the service life of concrete structure. It has become an important subject in the construction field. In this paper, organic film-forming coated concrete was studied. Epoxy resin topcoat, chlorinated rubber topcoat, polyurethane topcoat combined with epoxy zinc-rich primer were studied. Different coating systems combined with different water-cement ratio, the corrosion resistance of concrete under different aging conditions and the microstructure of the coating after aging were studied. The rules between the resistance to chloride erosion and the degradation of macro and micro properties of organic film forming coatings at different aging stages were obtained. A prediction model of organic film forming coatings was established based on natural climate conditions and coastal climate conditions. The main research results and conclusions are as follows: 1. Through the experimental study on the electrical flux of the coating concrete before aging, the anti-chloride protection ability of different coating systems is obtained. Paint: polyurethane epoxy resin chlorinated rubber. Paint according to system: polyurethane chlorinated rubber epoxy resin. With the addition of primer, the corrosion resistance of the coated concrete can be improved. Considering the cost, the best coating system is one-pass primer and one-pass polyurethane topcoat. When using organic coating on the surface to improve the durability of concrete, Considering the influence of concrete itself on chloride diffusion resistance, through the experimental study on the electric flux of the aged coated concrete, it is found that the electric flux value of the concrete increases with aging time after UV aging of epoxy resin coating system. The electric flux of concrete decreases with the increase of the thickness of epoxy resin coating system. The protective effects of various coating systems on concrete are as follows: polyurethane chlorinated rubber epoxy resin, and the thicker the coating film, the better the protective effect of the coating. As a method of accelerating the measurement of chloride permeation resistance of concrete in laboratory, the electric flux test has a good correspondence with the actual environment chloride ion erosion, and can reflect the protective effect of coating on concrete relatively truth.According to the experimental data, By regression analysis, the relationship between the electric flux of concrete and the aging time is analyzed, and the life prediction method of different coating system thickness in different service area is found. Compared with natural atmospheric aging, the average accelerated effect of ultraviolet aging is about 13.31 times, and that of coastal exposure aging is about 1.667 times. The analysis of the macroscopic change degree and microcosmic morphology before and after the aging of the coating shows that the decay of the resistance to chloride ion of the organic film coating with the aging of the coating is due to the production and development of the defects caused by the degradation and corrosion of the coating. Based on the service life of the coating and the cost of the coating system, The average annual cost of each coating system was obtained, and the average annual cost of the two-pass polyurethane coating system in primer was the lowest, which was the most economical without the consideration of labor cost.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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