矿渣—粉煤灰—水泥复合材料的钙溶蚀过程研究

发布时间：2018-01-10 16:17

本文关键词：矿渣—粉煤灰—水泥复合材料的钙溶蚀过程研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：长期处于各种河流、湖泊及海洋等复杂水环境下的混凝土等水泥基材料,易于遭受环境水侵蚀而发生混凝土耐久性退化和结构服役寿命降低等问题。为了揭示水环境下水泥基材料因钙溶蚀引起的耐久性退化问题,本文设计去离子水以及6M氯化铵溶液两种条件下掺有矿物掺和料的复合水泥硬化浆体的钙溶蚀实验,通过实验的测试以及利用模型进行数值模拟,研究了不同矿物掺和料对水泥硬化浆体的溶蚀性能的影响。主要的研究成果与结论如下:(1)通过设计去离子水腐蚀环境下,开展不同矿物掺和料对水泥基材料抗溶蚀性能的研究,并采用EDTA测定钙离子浓度法、饱水-干燥称重法、扫描电镜(SEM)和EDS等测试方法对掺有不同矿物掺和料的复合浆体在溶蚀过程中的钙离子溶出量、孔隙率、微观形貌以及钙硅比进行了测定,获得了软水腐蚀条件下不同矿物掺和料对水泥基材料溶蚀性能的影响规律。测试结果表明,粉煤灰和矿渣的掺入在一定程度上都能改善水泥浆体的抗溶蚀性能,但掺有矿渣的复合浆体抗溶蚀性能更好。(2)开展了 6M氯化铵加速溶蚀条件下粉煤灰-水泥复合浆体以及不同矿渣掺量的20%粉煤灰-水泥复合浆体圆柱试件的钙溶蚀实验研究,通过对复合浆体的溶蚀深度、孔隙率、钙硅比、微观结构以及XRD等进行试验测试,结果表明,粉煤灰-水泥复合浆体中掺入矿渣后,复合浆体的溶蚀性能得到明显提高。(3)建立了软水溶蚀条件下水泥基材料的钙溶蚀一维扩散模型,并考虑矿物掺和料对水泥基材料初始参数的影响,通过调整钙溶蚀模型的参数模拟了去离子水腐蚀条件下的薄片试件以及6M氯化铵腐蚀条件下的圆柱试件的钙溶蚀进程,将模型模拟计算结果与试验测试值进行对比分析,结果表明,两种腐蚀环境下试件的测试结果与模型模拟计算结果均具有较好的一致性,因此,该模型可对软水腐蚀条件下的水泥材料的钙溶蚀规律进行预测。
[Abstract]:In the long river, concrete and other cement-based materials in complex water environment of lakes and oceans under, prone to water erosion and the durability of concrete structure degradation and service life reduction. In order to reveal the cement-based materials under water environment caused by calcium dissolution durability degradation, dissolution of calcium doped composite cement the hardened paste of mineral admixture of the design of deionized water and 6M ammonium chloride solution under two conditions, through the experimental test and numerical simulation using the model, the influence of different mineral admixtures on the erosion resistance of the hardened cement paste was studied. The research results and conclusions of the thesis are as follows: (1) through the design of DI water corrosive environment, carry out different mineral admixtures on anti corrosion properties of cement based materials, and calcium concentration was determined by using the method of EDTA water saturated dry weighing method, Saul Scanning electron microscopy (SEM) and EDS test method with the amount of calcium ion solution composite slurry of different mineral admixtures in the process of dissolution of mixed porosity ratio were measured and microstructure of calcium silicon, the soft water under the condition of corrosion of different mineral admixture of cement based material dissolution properties. The test results show that the fly ash and slag mixed with anti corrosion properties of cement paste can be improved to a certain extent, but the composite slurry mixed with slag anti corrosion performance better. (2) developed 6M ammonium chloride under accelerated corrosion of fly ash cement composite slurry and 20% fly ash different slag cement composite slurry column experimental study of calcium dissolution parts, through the dissolution depth of composite slurry porosity, calcium silicon ratio, microstructure and XRD test, the results show that the fly ash cement composite slurry mixing Slag, the erosion resistance of composite slurry was improved. (3) the establishment of the calcium dissolution of cement-based materials one-dimensional diffusion model under the condition of water erosion, and considering the influence of mineral admixture on the initial parameters of cement based materials, by adjusting the parameters of calcium dissolution model to simulate the deionized water under corrosion sheet specimens 6M and ammonium chloride corrosion conditions of cylindrical parts test calcium dissolution process, the model simulation results and the test results were compared and analyzed, the results show that the two kinds of corrosion specimens with the test results of the model are consistent with the calculation results, the better result, the model can be calcium dissolution law of soft water under the condition of corrosion of cement materials were predicted.

【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU599

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