沙漠砂锂渣聚丙烯纤维混凝土力学性能及耐久性试验研究

发布时间：2018-01-14 14:44

本文关键词：沙漠砂锂渣聚丙烯纤维混凝土力学性能及耐久性试验研究　出处：《新疆大学》2017年硕士论文　论文类型：学位论文

【摘要】：沙漠砂混凝土是一种新型环保型混凝土,将沙漠砂按一定比例替代普通中砂,配置出符合工程实际要求的混凝土。沙漠砂混凝土基本力学性能及耐久性能与一般混凝土十分相近,然而因其较易收缩开裂,抗渗性不佳等问题而未被广泛使用,为了改善沙漠砂混凝土以上各项性能,通过掺入矿物掺合料锂渣和低弹性模量纤维的方法解决上述问题。锂渣是锂盐生产加工流程中大规模排放的工业固体废弃物,有效提高混凝土强度并改善混凝土抗渗和抗冻等耐久性能,而聚丙烯纤维能大幅度提升混凝土内部结构整体性,对混凝土抗拉强度有明显改善效用。新疆地区合理开发沙漠砂进行工程建设,降低工程造价,遏制荒漠化和沙尘暴,为生态环境做出贡献,从发展的长远角度看,有着深远的经济效益和社会效益。本文通过将新疆托克逊县沙漠砂按一定比例替代普通中砂配置混凝土,并利用工业废弃物锂渣和聚丙烯纤维对沙漠砂混凝土进行改性。对不同沙漠砂替代率下的锂渣聚丙烯纤维混凝土部分基本力学性能及耐久性深入探讨,分析了沙漠砂锂渣聚丙烯纤维混凝土的立方体抗压、劈裂抗拉、轴心抗压、受压应力—应变曲线等各项基本力学性能指标和抗冻性、抗渗性。试验研究表明:当沙漠砂替代率为30%时,试件力学及耐久性能最优异,并且通过峰值应变与轴心抗压强度数学表达式:εc=(80.02βfc-3737.86)×106,得到沙漠砂替代率影响系数。当掺入沙漠砂、聚丙烯纤维和锂渣后,立方体抗压强度提高了17.56%,轴心抗压强度提高了20.06%,劈裂抗拉强度提高了53.26%,且冻融后质量损失率降低了36.79%,立方体强度损失率降低了34.78%,动弹性模量损失率降低了25.5%,经加压水渗透后平均渗水高度降低了22.28%。综合考虑抗冻融性能中混凝土质量、强度、动弹性模量损失率整体趋势及抗渗性能中平均渗水高度,试验中各因素按影响程度排序为聚丙烯纤维锂渣沙漠砂。
[Abstract]:Desert sand concrete is a new type of environmental protection concrete. Desert sand is replaced by common medium sand in a certain proportion. The basic mechanical properties and durability of desert sand concrete are very close to those of normal concrete, but it is easy to shrink and crack. Problems such as poor impermeability are not widely used in order to improve the above properties of desert sand concrete. The above problems are solved by adding mineral admixture lithium slag and low elastic modulus fiber. Lithium slag is the industrial solid waste discharged on a large scale in the process of lithium salt production and processing. It can effectively improve the strength of concrete and improve the durability of concrete such as impermeability and frost resistance, while polypropylene fiber can greatly enhance the integrity of the internal structure of concrete. Xinjiang region reasonable development of desert sand for engineering construction, reduce engineering costs, contain desertification and dust storms, and make contributions to the ecological environment. From the long-term point of view of development, there are far-reaching economic and social benefits. In this paper, the desert sand in Tokeson County, Xinjiang, is replaced by concrete in proportion to ordinary medium sand. The sand concrete was modified by industrial waste lithium slag and polypropylene fiber. The basic mechanical properties and durability of lithium slag polypropylene fiber concrete with different desert sand replacement ratio were discussed. The basic mechanical properties and freezing resistance of Lithium slag polypropylene fiber concrete from desert sand are analyzed, such as cube compressive resistance, splitting tensile resistance, axial compression resistance, compressive stress-strain curve and so on. Impermeability. The experimental study shows that when the sand substitution ratio is 30%, the mechanical and durability of the specimen is the best. And through the mathematical expression of peak strain and axial compressive strength: 蔚 _ (CX) _ (80.02) 尾 _ (fc-3737.86) 脳 10 ~ (6), the influence coefficient of desert sand substitution rate is obtained. After polypropylene fiber and lithium slag, the cube compressive strength increased 17.56%, the axial compressive strength increased 20.06%, and the splitting tensile strength increased 53.26%. After freezing and thawing, the mass loss rate decreased by 36.79, the cube strength loss rate decreased by 34.78 and the dynamic elastic modulus loss rate decreased by 25.5%. The average percolation height is reduced by 22.28 after permeation of pressurized water. The concrete quality, strength, dynamic elastic modulus loss rate and average seepage height in the anti-freezing and thawing properties are considered comprehensively. According to the degree of influence, the factors in the test are polypropylene fiber lithium slag desert sand.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

【参考文献】