红粘土的改性及其机理研究

发布时间：2018-03-09 03:30

本文选题：红粘土　切入点：固硫灰渣　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国高速公路及各级公路的不断延伸，在红粘土地区修建的公路也逐渐增多。红粘土在我国主要分布在南方地区，作为路基填料时，存在大量路基病害问题，影响道路的强度和长期稳定性。因此，为促进红粘土地区的道路建设，应找到一种经济合理、施工方便的措施对红粘土进行改性，解决其作为路基填料时面临的问题。红粘土液限高，属于高液限土，作为路基填料时，收缩开裂比较严重。公路路基设计以及施工规范规定有些高液限土不能直接作为路基填料，必须通过处理后才能作为路基填料。常用的处理的方法有物理方法、化学方法以及物理化学结合的方法。本文采用的红粘土取自云南地区，通过物理性质的测定，发现液限和塑性指数，不能满足规范中对于直接作为路基填料的规定。因此将红粘土作为路基填料时，必须采用措施进行处理。本文主要通过掺加固硫灰渣对其改性，使其满足规范中对于路基填料的要求。通过进行不同固硫灰掺量下的液塑限、标准击实试验、加州承载比CBR试验、收缩试验、浇注成型试验等，测定不同固硫灰掺量下的强度、收缩变形及水稳定性。通过掺加固硫灰的直剪试验，比较在相同击实功、相同含水率的情况下，粘聚力和内摩擦角的变化规律。路基填料改性过程中传统改性材料有水泥、石灰等，通过在红粘土中掺加固硫渣，与掺加水泥、石灰的液塑限、强度、水稳定性比较研究。研究固硫渣对红粘土的强度、变形基水稳定性的影响，对比不同改性材料对红粘土的影响，得出改性规律。固硫灰渣改性红粘土微观机理研究，在红粘土中掺加固硫灰渣，改变了红粘土的土体结构连接形式，固硫灰渣与红粘土反应生成新的胶凝物质，紧密的胶结起来。红粘土中的微孔隙结构多，固硫灰渣的细度大，既可以填充孔隙结构，又能胶结成整体。固硫灰渣在水化的过程中吸收大量的水分，形成结合水，并且具有膨胀性，减小了因失水引起的收缩变形。
[Abstract]:With the continuous extension of highway and highway at all levels in our country, the number of highways built in red clay area is increasing gradually. Red clay is mainly distributed in the south of China, and there are a lot of roadbed diseases when it is used as subgrade filler. Therefore, in order to promote the road construction in the red clay area, an economical and convenient measure should be found to modify the red clay and solve the problems when it is used as the filling material of the roadbed. Red clay has high liquid limit and belongs to high liquid limit soil. When used as subgrade filler, shrinkage cracking is serious. Some high liquid limit soil can not be used as roadbed filler directly according to highway roadbed design and construction code. The common methods of treatment include physical method, chemical method and physico-chemical combination method. The red clay used in this paper is taken from Yunnan area. Through the determination of physical properties, it is found that the liquid limit and plastic index can not meet the requirements of the code for the direct subgrade filling. Therefore, when the red clay is used as the subgrade filler, Measures must be adopted to treat it. In this paper, the sulfur ash is modified to meet the requirements of subgrade fillers in the code, and the standard compaction test is carried out under the liquid plastic limit of different amount of sulfur fixing ash. California bearing ratio CBR test, shrinkage test, pouring molding test, etc., to measure the strength, shrinkage deformation and water stability of different sulfur fixed ash content. In the case of the same moisture content, the change of cohesion and internal friction angle is regular. In the course of roadbed filler modification, the traditional modified materials include cement, lime and so on. By adding sulfur slag in red clay, comparing with the liquid plastic limit, strength and water stability of cement and lime, the strength of sulfur fixation slag to red clay is studied. The effect of deformable base water stability on red clay was compared with that of different modified materials, and the modification law was obtained. The microscopic mechanism of sulfur fixation ash modified red clay was studied. The structure of red clay was changed by adding sulfur ash into red clay, and a new cementitious substance was formed by the reaction of fixed sulfur ash with red clay. Tight cementation. Red clay has a large number of micropore structures and large fineness of sulfur fixation ash, which can not only fill the pore structure but also form a whole. The sulfur fixing ash absorbs a large amount of water in the process of hydration to form a combined water. Moreover, it has expansibility and reduces the shrinkage and deformation caused by water loss.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414

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