废旧轮胎片体一风化料混合料土工特性室内试验研究

发布时间：2018-01-03 12:29

本文关键词：废旧轮胎片体一风化料混合料土工特性室内试验研究　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：废旧轮胎作为一种易燃、难以降解的材料对自然环境造成了极大影响,尤其是现如今经济快速发展、汽车数量越来越多,废旧轮胎导致的"黑色污染"问题也日益突出。对废旧轮胎的处理和利用的方法有很多,包括轮胎原型直接利用、堆存填埋、燃料焚烧、热解、翻新、机械破碎等,但存在废旧轮胎回收率低、能源消耗高、加工再利用过程中出现二次污染等现象。我国橡胶资源匮乏,同时废旧轮胎综合回收利用产业的发展速度跟不上汽车制造业的发展速度,也无法适应目前严峻的资源环境形势要求,因此妥善处理废旧轮胎,减少对资源环境的耗费和破坏,这是亟待待解决的一大难题。通过机械破碎得到的废旧轮胎片体(tire-derived aggregate,简称TDA)质量轻、耐久性好、不易降解、强度高、吸附性和排水性优良,主要应用于公路路基、挡墙、桥台和防冻胀层等作为道路工程的回填料、吸附介质或隔震材料等,能够提高结构基础承载力、降低沉降变形。废旧轮胎片体通过与土体的混合,可以改善土体工程性能,得到轻质高强的混合材料。本论文采用TDA和风化料(weathered rock material,简称WRM)材料,通过开展一系列室内土工试验,研究了废旧轮胎片体-风化料(TDA-WRM)混合料的土工特性。采用不同质量分数轮胎片体掺入风化料,制备不同含水率混合料。通过大尺寸击实设备开展重型击实试验,得到了不同含水率条件下混合料的干密度变化。击实结果表明,在风化料中掺入废旧轮胎片体不但能够有效降低混合料的自重,还能减小水的用量,另外随着混合料中废旧轮胎片体质量分数的增加,混合料击实曲线相比风化料的击实曲线出现了明显变化,通过对比与探讨,研究了 TDA-风化料混合料的压实机理。在有侧限的条件下对TDA-风化料混合料进行了压缩试验,研究在垂直荷载的作用下,混合料中TDA材料质量分数和含水率对压缩性能的影响。试验结果表明,混合料在第一次加载卸载过程中产生的永久性变形量最大,之后的循环过程中产生的永久性变形量逐渐减小;随着混合料中TDA材料的增加,试件压缩回弹曲线的重合度越来越高,压缩应变明显增大,在外力荷载作用下混合料表现出显著的沉降变形;含水率在TDA材料含量较低时对混合料永久性变形影响较大,随片体含量的增加混合料对水的敏感程度逐渐降低。为研究TDA-风化料混合料的渗透性,研发了一种新型的大尺寸变水头渗透仪,通过渗透试验研究了 TDA材料含量与含水率对混合料渗透性的影响。试验结果表明,风化料中掺入TDA能够有效增加混合料的渗透性。在片体含量较低时混合料在最优含水率处渗透性最低,混合料内部孔隙率较小,处于密实状态;当片体含量增大时,渗透系数明显变大,混合料渗透性增强,且随含水率的增大,渗透性呈现出增大趋势。
[Abstract]:Waste tires as a flammable, difficult to degrade materials have a great impact on the natural environment, especially today's rapid economic development, more and more cars. The problem of "black pollution" caused by waste tires is becoming more and more serious. There are many methods to deal with and utilize used tyres, including direct use of tire prototype, landfill, burning of fuel, pyrolysis and retreading. Mechanical crushing, but there are some phenomena such as low recovery rate of waste tires, high energy consumption, secondary pollution in the process of processing and reuse, etc. The rubber resources in our country are scarce. At the same time, the development speed of waste tire comprehensive recycling industry can not keep up with the development speed of automobile manufacturing industry, nor can it adapt to the severe resource and environmental requirements at present, so the waste tire should be properly handled. Reducing the consumption and destruction of resources and environment is a difficult problem to be solved. Referred to as TDAs, they are light in weight, good in durability, hard to degrade, high in strength, good in adsorption and drainage, and mainly used in road subgrade, retaining wall, bridge abutment and anti-frost heaving layer as backfill for road engineering. The adsorption medium or isolation material can improve the bearing capacity of the structure foundation and reduce the settlement deformation. The waste tire can improve the engineering performance of the soil by mixing with the soil. In this paper, TDA and weathered material weathered rock material (WRM) were used to obtain lightweight and high strength materials. Through a series of indoor geotechnical tests, the geotechnical characteristics of TDA-WRM mixture were studied. The mixture with different moisture content was prepared. The dry density change of the mixture under different moisture content was obtained by heavy compaction test with large size compaction equipment. The compaction results showed that. Adding waste tire into weathered material can not only effectively reduce the weight of mixture, but also reduce the amount of water. In addition, with the increase of the mass fraction of waste tire in the mixture. Compared with the compaction curve of weathering material, the compaction curve of mixture has changed obviously, through comparison and discussion. The compaction mechanism of TDA-weathered mixture was studied. The compression test of TDA-weathered mixture was carried out under the condition of side limit, and the effect of vertical load was studied. The effect of TDA material mass fraction and moisture content on the compression performance. The experimental results show that the permanent deformation of the mixture is the largest during the first loading and unloading process. The amount of permanent deformation produced in the later cycle gradually decreases. With the increase of TDA material in the mixture, the coincidence degree of the compression springback curve of the specimen is higher and higher, the compressive strain obviously increases, and the mixture shows significant settlement deformation under the external force load. The moisture content has a great influence on the permanent deformation of the mixture when the content of TDA material is low, and the sensitivity of the mixture to water gradually decreases with the increase of the content of the sheet body. In order to study the permeability of the mixture of TDA-weathering material. A new type of large size variable head permeator was developed. The influence of TDA material content and moisture content on the permeability of mixture was studied by permeation test. The experimental results showed that the permeability of the mixture was influenced by the content of the material and the moisture content of the mixture. Adding TDA into weathering material can effectively increase the permeability of mixture. When the content of sheet body is low, the permeability of mixture is the lowest at the optimum moisture content, and the internal porosity of the mixture is small, and the mixture is in a dense state. With the increase of sheet content, the permeability coefficient increases obviously, the permeability of mixture increases, and the permeability increases with the increase of moisture content.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U414

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