砒砂岩体溃散机理及砒砂岩改性材料试验研究

发布时间：2018-05-30 19:28

  本文选题：砒砂岩 + 溃散机理　； 参考：《大连理工大学》2016年博士论文

【摘要】：砒砂岩遇水溃散的特性造成了内蒙古砒砂岩地区严重的水土流失。为了治理当地的水土流失和促进植被的恢复,需要采用淤地坝和植被固沙相结合的措施对其进行治理。而该地区地形千沟万壑导致交通极度不便,大规模从外面运进筑坝材料非常困难且成本过高。为了便于就地取材,本文通过对砒砂岩基本特性和溃散机理的研究找到了砒砂岩的改性方法,将砒砂岩改性成可用于淤地坝建设的坝身材料和过水材料,同时对改性材料的性能及影响因素展开了详细的研究。基于砒砂岩改性技术,研制出砒砂岩改性免烧砖并利用砒砂岩改性坝身材料在当地修建了一座小型淤地坝,初步实现砒砂岩改性材料的资源化利用。本文的主要研究内容和得到结论如下所示：(1)通过材料分析方法明确了砒砂岩的矿物组成和结构组成。砒砂岩是由石英、钠长石和钾长石等支撑颗粒物、膨胀粘土(蒙脱石和绿泥石等)和游离氧化物(三氧化二铁)等胶结物所构成的颗粒支撑渗透式结构,在此基础上建立起砒砂岩的三元结构物理模型,为砒砂岩的进一步研究奠定基础。(2)通过对砒砂岩基本性能及溃散过程的研究,揭示了砒砂岩溃散的根本原因在于自身胶结差且胶结物大部分为膨胀粘土矿物(胶结力不足以约束膨胀作用),并利用胶结指数和溃散指数评价了砒砂岩的胶结性能和溃散性能。结合三元结构物理模型及溃散试验,建立了砒砂岩遇水溃散过程的物理模型,提出了游离氧化物胶结增强改性的方法。(3)结合复合材料强度理论及土体的强度理论推导出砒砂岩强度的数学模型(fp=K×Pg×.fg+2C×(1-Pg)tan(45°+φ/2)),为砒砂岩增强胶结改性提供理论基础。通过向砒砂岩中加入适量的游离氧化物提高胶结指数和采用阳离子交换技术抑制膨胀辅助进一步降低溃散指数,实现对砒砂岩的胶结增强改性,研制出价格低廉、绿色无污染且性能满足要求(抗压强度大于1MPa,膨胀率小于5%以软化系数大于0.2)的砒砂岩改性坝身材料。(4)基于砒砂岩的矿物风化特性及规律,提出砒砂岩加速风化及激活改性方法。将砒砂岩中粘土弱胶结矿物(蒙脱石和绿泥石等)、部分钠长石、部分钾长石和添加的矿粉转化为耐水高强胶凝物质(水化硅铝酸钙、沸石和Si-Al胶体等),实现对砒砂岩的胶结增强改性。采用试验证实砒砂岩加速风化改性技术的可行性,并初步研制出砒砂岩改性过水材料,其最高抗压强度为46MPa、软化系数到达0.95。改性过水材料的反应产物为水化硅酸钙、水化硅铝酸钙、类沸石以及Si-Al胶体(地聚物)等。(5)在砒砂岩加速风化及激活改性方法的基础上,通过对砒砂岩进行高温煅烧以及添加适量表面活性剂,提高了浆体的流动性,实现了改性材料的浇筑成型,初步研制出砒砂岩改性胶凝材料,拓宽了改性材料的适用范围。并利用绝对体积法和线性拟合的方法得出砒砂岩加速风化及激活改性材料的材料组成设计方法。(6)基于砒砂岩加速风化及激活改性技术,初步研制出砒砂岩改性免烧砖缓解当地建筑用砖缺乏的局势,并在内蒙古鄂尔多斯二老虎沟建立了改性砒砂岩小型试验淤地坝。
[Abstract]:In order to control the local soil and water loss and promote the restoration of the vegetation, the combination of the silt dam and the vegetation and sand fixation should be adopted to control the soil erosion and soil erosion in the Inner Mongolia arsenic sandstone area. The material of the dam is very difficult and high cost. In order to make it easy to obtain the material, this paper finds the modification method of the arsenic sandstone through the study of the basic characteristics and the collapsing mechanism of the arsenic sandstone, and modifier the soft rock into the material of the dam body and the material that can be used for the construction of the silt dam. At the same time, the properties and the influencing factors of the modified material are studied in detail. Based on the modification technology of arsenic sandstone, a modified soft rock brick was developed and a small silt dam was built using the material of the modified rock dam. The main research content and conclusion of this paper are as follows: (1) the arsenic sandstone is clearly defined through the material analysis method. Mineral composition and structure composition. The arsenic sandstone is a porous structure supported by particles such as quartz, sodium feldspar and potassium feldspar, swelling clay (montmorillonite and chlorite etc.) and free oxide (iron oxide). On this basis, the physical model of the three element structure of arsenic sandstone is established, which is the one of the arsenic sandstone. 2. (2) through the study of the basic properties and the collapsing process of the arsenic sandstone, it is revealed that the fundamental reason for the collapse of the arsenic sandstone lies in its poor cementation and most of the cementation of the swelling clay minerals (the cementation force is not sufficient to restrain the expansion). The cementation index and the collapsing index are used to evaluate the cementation property and the collapsing of the arsenic sandstone. In combination with the physical model of three element structure and the collapsing test, the physical model of the water collapsing process of the arsenic sandstone is established. The method of strengthening the free oxide cementation is proposed. (3) the mathematical model of the strength of the arsenic sandstone (fp=K x Pg x.Fg+2C * (1-Pg) Tan (45 + [45] /2) is derived by combining the strength theory of the composite material and the strength theory of the soil. It provides a theoretical basis for strengthening the cementation of soft rock. By adding a proper amount of free oxide to the arsenic sandstone and improving the cementation index and using the cation exchange technique to reduce the swelling index, the cementation of the arsenic sandstone is further reduced, and the cementation of the arsenic sandstone is enhanced, and the price is low, the green is no pollution and the performance meets the requirements. The sandrock material is modified by soft rock with a degree of greater than 1MPa and less than 5% with a softening factor of more than 0.2. (4) based on the mineral weathering characteristics and regularity of the arsenic sandstone, the accelerated weathering and activation modification methods of arsenic sandstone are proposed. The clay sandstone in the sandstone (montmorillonite and chlorite), partial albite, partial potassium feldspar and added mineral powder are used. It is transformed into a water resistant and high-strength cementitious substance (calcium aluminosilicate, zeolite and Si-Al colloid) to improve the cementation of arsenic sandstone. The feasibility of testing the weathering modification technology of solid arsenic sandstone to accelerate weathering modification is tested, and the modified water material of arsenic sandstone is preliminarily developed, its maximum compressive strength is 46MPa, and the softening coefficient reaches 0.95. modified water material. The reaction products are hydrated calcium silicate, hydrated calcium aluminosilicate, zeolite and Si-Al colloid (geopolymer). (5) on the basis of accelerated weathering and activation modification methods of arsenic sandstone, the fluidity of the slurry was improved by high temperature calcination and adding a proper amount of surfactants. The preliminary research on the molding of the modified material was achieved. The modified gelatin material of arsenic sandstone has been made to broaden the scope of application of modified materials. The method of material composition for accelerated weathering and activation of modified materials is obtained by using the method of absolute volume and linear fitting. (6) based on accelerated weathering and activation modification technology of arsenic sandstone, a preliminary development of soft clay sandstone modified free brick to alleviate the local conditions The lack of building brick situation, and the two tiger grooves in Erdos, Inner Mongolia, has set up a small scale test dam for modified sandstone.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TV41;S157
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本文编号：1956500