冻融循环和氯离子侵蚀下水泥基灌浆料力学性能试验研究

发布时间：2019-01-26 14:29

【摘要】：青海盐湖地区由于其特殊的地理环境,使得当地的建筑物结构因季节性的冻融循环和氯离子侵蚀遭受严重的损害。冻融循环及氯离子侵蚀相互促进,相互递进,致使盐湖及其周边混凝土结构因腐蚀破坏而寿命缩短。因此,提高盐湖地区混凝土结构耐久性的问题迫在眉睫。本文尝试研制一种抗氯离子侵蚀的水泥基灌浆料作为防腐材料,从而有效保护混凝土抵抗氯离子侵蚀及冻融破坏,提高混凝土结构的耐久性。本文从水泥基灌浆料的材料选取、配合比设计和耐久性方面进行系统的研究,分析及优化了各因素对灌浆料性能的影响,取得了一定的成果,对今后工程的实际应用及研究具有十分重要的意义。论文的主要研究内容及成果如下:(1)采用正交法研究了水胶比、胶砂比、硅灰、粉煤灰、膨胀剂及减水剂对水泥基灌浆料流动性及强度的影响,获得了对灌浆料性能影响显著的因素,初步优化灌浆料配合比参数。(2)通过单一变量试验,深入分析研究水胶比、胶砂比、硅灰、粉煤灰及减水剂对水泥基灌浆料抗压及抗折强度的影响,进一步优化配合比参数,获得了物理力学性能较好的水泥基灌浆料;另外,通过掺加适量的消泡剂不仅改善了灌浆料的表面性质,又提高了灌浆料的强度,取得了良好的改性效果。(3)进行了水泥基灌浆料在10%、15%和20%三种浓度的盐溶液中抗冻融循环试验。试验结果表明,灌浆料强度及质量随冻融循环次数的增加先增加后降低;在15%盐溶液中的灌浆料强度及质量损失率较大,而20%的高浓度盐溶液有效降低了冰点,有利于试件的抗冻,但试件在盐溶液中冻融的损失均比在水中的严重。(4)研究了水泥基灌浆料试件在10%、15%和20%三种浓度的盐溶液中长期浸泡试验。结果表明,试件强度耐蚀系数随浸泡时间的增加先增加后降低;随盐溶液浓度的增加不断降低。在20%盐溶液中浸泡9个月的试件的氯离子侵蚀深度为3.20,且侵蚀速率明显降低,说明灌浆料具有良好的抗氯离子侵蚀性能。
[Abstract]:Due to its special geographical environment, the local building structure is seriously damaged by seasonal freeze-thaw cycle and chloride ion erosion. The freeze-thaw cycle and chloride erosion promote each other, which results in the shortening of the life of the concrete structure of salt lake and its surrounding area due to corrosion damage. Therefore, it is urgent to improve the durability of concrete structure in salt lake area. This paper attempts to develop a kind of cement based grouting material which is resistant to chloride ion erosion as anticorrosive material so as to effectively protect concrete against chloride ion erosion and freeze-thaw damage and improve the durability of concrete structure. In this paper, the material selection, mix ratio design and durability of cement-based grouting materials are systematically studied, and the effects of various factors on the performance of grouting materials are analyzed and optimized, and some achievements are obtained. It is of great significance to the practical application and research of the future engineering. The main research contents and results are as follows: (1) the effects of water-binder ratio, cement-sand ratio, silica fume, fly ash, expander and water reducer on the fluidity and strength of cement based grouting were studied by orthogonal method. The factors influencing the performance of the grouting material were obtained, and the mixing ratio parameters of the grouting material were preliminarily optimized. (2) through the single variable test, the water binder ratio, the cement-sand ratio, the silica fume ratio, the water-binder ratio, the cement-sand ratio, the silica fume ratio, The effects of fly ash and water reducer on compressive and flexural strength of cement based grouting materials were studied. In addition, the addition of proper amount of defoamer not only improves the surface properties of the grouting material, but also improves the strength of the grouting material. Freezing and thawing resistance test in salt solution of 15% and 20%. The results showed that the strength and quality of grouting materials increased firstly and then decreased with the increase of freeze-thaw cycles. The strength and mass loss rate of the grouting material in 15% salt solution is large, while 20% high concentration salt solution can effectively reduce the freezing point, which is beneficial to the freezing resistance of the sample. But the loss of freezing and thawing in salt solution was more serious than that in water. (4) the long-term soaking test of cement based grouting material in 10% and 20% salt solution was studied. The results show that the corrosion resistance coefficient of the specimen increases first and then decreases with the increase of soaking time, and decreases with the increase of salt concentration. The chloride erosion depth of the sample soaked in 20% salt solution for 9 months was 3.20, and the erosion rate was obviously decreased, which indicated that the grouting material had good resistance to chloride ion erosion.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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