【作者】 吴长发；

【导师】 叶跃忠；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 硫酸盐侵蚀是混凝土化学侵蚀中最广泛和最普通的形式，一直是结构耐久性研究中的重要组成部分，尽管到目前为止所提出的抗硫酸盐侵蚀试验方法有许多种，但是每种方法都具有一定的局限性，没有一种方法能快速而真实地揭示混凝土硫酸盐侵蚀的机理，尤其是用于长期预报混凝土处于硫酸盐侵蚀环境中的各种性能。因此，对抗硫酸盐侵蚀试验方法进行全面系统的研究就显得尤为重要。现今国标中的试验方法主要用于对水泥胶凝材料本身的抗硫酸盐侵蚀性能进行评价，以水泥砂浆试件的方式进行试验。由于混凝土的抗硫酸盐侵蚀性能不仅与其所用的水泥胶凝材料有关，还与其密实性等有很大的关系，因此不同研究者在对混凝土的抗硫酸盐侵蚀性能进行研究时，根据其研究目的的不同而采用不同的试验方法。本论文以掺粉煤灰和防腐剂的混凝土为研究对象，探讨水泥胶砂和混凝土抗硫酸盐侵蚀试验方法及其评价指标，包括国家标准和一些科研院所提出的试验方法。对各种方法的试验参数加以修改，从中得出更为实际可行的试验参数和相关指标。同时，借助扫描电镜技术从微观角度对混凝土抗硫酸盐侵蚀和各试验方法进行微观机理分析。水泥胶砂抗硫酸盐侵蚀试验采用国标GB＼T 2420—81和GB＼T 749—2001。考察粉煤灰和防腐剂的抗硫酸盐侵蚀性能，考察用砂的粒径变化、成型压力变化等对试验结果的影响及抗蚀系数和膨胀率的指标分析。混凝土抗硫酸盐侵蚀试验采用干湿循环和长期浸泡两种方法。考察立方体和棱柱体抗硫酸盐侵蚀的敏感性，浸泡溶液温度和浓度对混凝土抗硫酸盐侵蚀的影响，不同强度等级的混凝土抗硫酸盐侵蚀的能力，以及干湿循环和长期浸泡试验结果的对比分析。研究表明：相同配合比的水泥胶砂试件和混凝土试件抗硫酸盐侵蚀性能一致；干湿循环和长期浸泡试验结果相一致；通过改变试验方法的相关参数可以得到较理想的试验效果。更多还原

【Abstract】 The sulfate attack is the most extensive and common form in the concrete chemical corrosion, and it has been an important part of structure durability research. Although so far there are many sulfate attack test methods that had been proposed, each method has some limitations and not any method can reveal concrete sulfate attack mechanism quickly and truthfully, especially is used to forecast various capability of concrete that is in the sulfate attack environment for long term. Therefore, it is very important to investigate test method of resistance to sulfate attack systematically.Now the national standard test methods are mainly used to evaluate capability of resistance to sulfate attack of cement gel material. Resistance to sulfate attack of concrete relates to not only cement gel material but also its compactness. Thus, different researchers in the resistance to sulfate attack study, according to different research purposes, adopt different test methods.In this paper, object of study is concrete containing fly ash and preservatives. Discuss test methods and evaluation parameter of resistance to sulfate attack of cement mortar and concrete which include test methods of national standards and some of the scientific research institutes. Test parameters of the various methods are modified in order to obtain actually more feasible experimental parameter and correlative evaluation parameter. At the same time, microscopic mechanism of all methods is analysed by using the scanning electron microscope technology from microcosmic point of view.GB\T 2420—81 and GB\T 749—2001 are about resistance to sulfate attack of cement mortar. Main study contents of cement mortar are resistance to sulfate attack of fly ash and preservatives, size changes of sand particle, pressure changes of manufacture and evaluation parameter about corrosion resistance coefficient and bulge ratio.Resistance to sulfate attack test methods of concrete adopt drying-wetting cycles and long-term immersion. Main study contents of concrete are sensitivity of cube and prism, influence of solution temperature and concentration on resistance to sulfate attack, resistance to sulfate attack capability of different intensity levels of concrete and comparing analysis between drying-wetting cycles and long-term immersion.The result shows that resistance to sulfate attack capability of the same proportion of cement mortar and concrete specimens is accordant, the results of drying-wetting cycles and long-term immersion are accordant, the ideal test results can be gained by changing the relevant parameters of the methods.更多还原