【作者】 李丽芬；

【导师】 曹德光；

【作者基本信息】 广西大学 ， 化学工艺， 2008， 硕士

【摘要】 红土是我国南方地区广泛存在的一种来源广泛的工程材料,该种材料在工程领域应用广泛,但与其他材料复合使用时存在强度低和水稳性差等工程特性,因而对固化红土体系极其性能的研究具有重要的现实和科学意义。本文主要针对采用水泥、消石灰和半水石膏作为固化剂来对红土进行固化的土壤固化体系的组成与性能关系进行研究,为该体系用于实际工程提供理论指导。本文以材料的结构与性能原理和体系的制备过程中的物理化学变化特征为主线,对体系的原材料、制备过程、产物和性能方面展开了研究。在原料方面,本文采用XRD和SEM等手段主要对红土物理力学特性、矿物组成和微观结构等进行了分析。结果表明:本试验所用的红土的主要矿物为:石英、高岭石、蒙脱石和伊利石和铁矿,且该红土中粘土矿物的含量约为:86%。对制备过程中的物理化学变化过程和产物特性的研究,主要采用单掺、双掺和三掺试验系统研究了水泥、消石灰和半水石膏的掺入量对红土固化强度和水稳性能的影响,并采用XRD和SEM等手段对其产物的结构、组成和特征进行了分析。单掺试验发现:水泥掺入量对红土固化强度和水稳性能有两种增长规律和两个界点分别为28%和50%,水泥在这两种增长过程中所起作用不同;消石灰和半水石膏的掺入对红土有一定的固化效果,但固化性能弱于水泥;双掺试验发现:水泥与消石灰或半水石膏双掺时有复合效应的存在,且双掺时的消石灰和半水石膏在固化材料中的最佳掺入比例为12.5%,并根据双掺的效果确定了三掺试验过程中各种固化材料的掺入的比例范围;三掺实验发现:水泥、消石灰和半水石膏三掺时存在复合效应,在水泥-消石灰-半水石膏三元相图中,在气养条件下强度呈带状规律分布,水养条件下强度随水泥掺量的降低逐渐降低,在富半水石膏部分强度为零。另外,本文对含砂量发现:在固化体系中加入砂强度迅速增加,掺砂量达到30%时随掺砂量的增加强度增加幅度降低,此实验结果对后续实验和实际应用提供了依据。更多还原

【Abstract】 Red clay is a kind of engineering material which exists widely in our country, and has been widely applied in engineering field, but it has some shortcomings such as the low compressive strength, the lack of water stability. So the study of the solidly red clay is of great practical and scientific significance. This article mainly studied the relationship between content and cure properties when used cement, hydrated lime and hemihydrates gypsums soil stabilizer, which provided a theoretical guidance to the practical project.The article took material structure, principle of capability and physical chemistry changes in the system synthesis process as the main lines, then researched the raw materials, synthesis process, production and capability of system. In raw materials, the article analyzed the physical mechanic of red clay, mineral compositions and micro-structure by XRD and SEM. The result show the red clay contain quartz, kaolin, elite and calcite, moreover clay content is 86%.For study of physical chemistry changes and production characteristic in the synthesis process, the article researched the effect of stabilizer (cement, hydrated lime and hemihydrates gypsums) ratio through single-doped, co-doped and tri-doped experiments. The single-doped experiment indicated that the water cure capacity and compressive strength have two kind of increasing regularity and two critical point which is 28% and 50% with various cement mixing amount, and cement take two different effects on the different of increasing regularity; when mixing hydrated lime or hemihydrates gypsum, there were a weaker cure effect. It exists the composite effect in the co-doped experiment of hydrated lime or hemihydrates gypsum and cement, and the optimum ratio of hydrated lime -mixing ratio or hemihydrates gypsum-mixing is 12.5% which determines the mixing range of cure material in the tri-doped experiment. In the cement-hydrated lime-hemihydrates gypsums phase diagram, the strength of production distributes as stripes in the air maintenance condition, but the strength decreases with cement content in the water maintenance condition, and the zone of rich gypsum’ strength is minimum. Finally, the result show the strength of cure system increases quickly with sand content, and increasing speed decreases when sand content reach 30%, which provides the theoretical basis for the future experiments and practicality applications .更多还原