棉花秸秆—脱硫石膏基固化桩的工程力学测试研究

发布时间：2018-01-29 20:53

本文关键词： 棉花秸杆脱硫石膏固化桩力学性能配合比　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：棉花秸秆是棉花种植的主要副产物,对其有效的处理是一个关乎环境保护和资源利用的问题。本文以解决这一问题为出发点,立足于棉花秸秆良好的物理力学性能,将其类比于钢筋混凝土中的"钢筋"用于地基后期加固,为棉花秸秆的大量消耗提供了一种有效途径。作为燃煤电厂烟气脱硫的重要副产物,脱硫石膏的循环利用受到许多学者的关注,但这些研究大部分需要将脱硫石膏煅烧形成建筑脱硫石膏以激发活性。本文则另辟蹊径,在原状脱硫石膏中加入矿渣、土、激发剂来形成脱硫石膏基胶凝材料用做地基加固固化剂。并将固化胶凝材料灌入到秸秆捆中经固化硬化成为棉花秸秆-脱硫石膏基固化桩。固化桩可以与土形成桩体复合地基来增强吹填土的强度。课题前期在前人研究基础上通过单因素实验和对比实验确定了固化桩成分的掺加范围和实验条件。之后用正交实验方法研究了棉花秸秆的密度、矿渣与脱硫石膏的质量比、水添加量、激发剂掺量这5个因素对棉花秸秆-脱硫石膏基固化桩的物理特征和力学性能的影响,主要包括密度、抗压强度、抗折强度、弹性模量、软化系数、吸水率等。不同配合比的固化桩试件中,最高抗压强度为14.69MPa、最高抗折强度达到1.24 MPa、软化系数最大为0.97,说明了棉花秸秆-脱硫石膏基材料有优秀的应用前景。在工程现场的实验条件下,对因素影响下的各性能进行分析,确定了固化桩在实践中使用的最优配比:A2B3C3D3E4,即在30%土,28%脱硫石膏和42%矿渣中加入水固比为0.25的水、1.5%的NaOH和15g/cm3的棉花秸秆。制成的固化桩不仅尺寸规整、密度适中、返霜量少、并且在满足一定抗压强度的条件下有着较高的抗折、抗变形、抗软化的性能。进一步结合固化桩材料的机理研究,阐释了拌合物结合的固化硬化过程、净浆与秸秆之间的连接方式,为秸秆加固吹填土、秸秆加筋胶凝材料、脱硫石膏基净浆等领域的研究开展起到借鉴作用。
[Abstract]:Cotton straw is the main by-product of cotton planting, its effective treatment is a matter of environmental protection and resource utilization. In order to solve this problem as a starting point, based on the physical and mechanical properties of cotton straw good, the analogy to the reinforced concrete reinforced foundation for later reinforcement, provide an effective way for the large consumption of cotton straw. As an important byproduct of coal-fired power plant flue gas desulfurization, desulfurization gypsum recycling has been focused by many scholars, but most of these studies will need to form the construction of desulphurization gypsum desulfurization gypsum calcination to stimulate activity. This is another way, adding slag, in FGD gypsum in the soil. To form a foundation reinforcement activator for curing agent of gypsum based cementitious materials. And the curing of cementitious material poured into the straw after curing hardens into cotton straw - off The sulfur gypsum curing. Curing pile pile can form pile composite foundation and soil to enhance the dredger fill strength. The previous study on the basis of previous studies by single factor experiment and contrast experiment to determine the range of experimental conditions and adding curing pile composition. After using the orthogonal experiment method to study the cotton straw density, quality of slag with the desulfurization gypsum ratio, water content, affect the physical characteristics of cotton straw gypsum based curing piles and the mechanical properties of the activator content of these 5 factors, including density, compressive strength, flexural strength, elastic modulus, softening coefficient, water absorption rate. Different curing ratio of pile specimens in the highest compressive strength was 14.69MPa, flexural strength reached 1.24 MPa, the maximum softening coefficient is 0.97, the cotton straw gypsum based materials have excellent application prospect. On the site under the experimental conditions, The performance factors were analyzed to determine the optimal proportion of curing piles used in practice: A2B3C3D3E4, which is 30% in the soil, adding water solid ratio of 0.25 water 28% desulfurization gypsum and 42% slag, 1.5% NaOH and 15g/cm3 made of cotton straw. Curing pile not only size regular, moderate density back, frost less, and resistance to deformation under certain conditions with compressive strength bending strength, high performance, resistance to softening. Combining with the mechanism of curing pile materials, curing and hardening process of mixture combination explains the connection between the paste and straw, straw reinforcement for dredger fill that straw reinforced cementitious materials, study on desulfurization gypsum paste and other areas to carry out reference to the role.

【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1

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