微波活化胶粉制备橡胶沥青的改性机理研究

发布时间：2019-06-14 23:46

【摘要】：废旧轮胎作为汽车工业最主要的固体废弃物之一,给生态环境保护带来巨大的压力。此外,道路交通方面的压力在于与之紧密相关的各种路面病害。橡胶沥青作为一种环保优质的道路工程新材料,在消耗废旧轮胎胶粉和提高道路交通服务水平方面具有良好的效果,但储存稳定性差却制约着橡胶沥青的推广应用。因此,如何提高橡胶沥青储存稳定性,延长沥青路面使用寿命,提高沥青路面服务水平成为了行业内工作者亟待解决的问题。对胶粉进行活化处理后生产改性沥青为上述问题提供了解决途径。本文采用微波活化方法对废旧胶粉进行活化处理,制备橡胶沥青并用沥青筛过滤得到不含胶粉的橡胶沥青结合料,采用布氏粘度(BV)、动态剪切流变(DSR)对比研究胶粉活化前后橡胶沥青的路用性能,在此基础上,推荐活化胶粉制备高性能橡胶沥青的制备工艺与参数。结果表明,废旧轮胎胶粉微波活化时间为90s时,胶粉改性沥青具有最佳的粘性及高温稳定性。活化胶粉改性沥青的复数剪切模量值与相应的IE存在线性正相关,IE越高,其相应的复数剪切模量值越大;活化胶粉改性沥青的复数剪切模量值与相应的PE存在线性正相关,PE越高,其相应的复数剪切模量值越大。对活化前后的胶粉进行扫描电子显微镜实验和比表面积测试,分析微波活化废旧轮胎胶粉表观形貌的影响以及比表面积的变化情况,结合活化前后胶粉改性沥青性能变化情况,对改性机理进行分析研究。通过实验得出,微波辐射使胶粉中增加了很多微孔,这些微孔提高了胶粉的比表面积。经过微波处理的胶粉都表现出不同程度的团聚现象,颗粒之间间距变小,表面孔隙有所增多,且随着微波处理时间的增加其团聚现象有所增加,表面孔隙有致密的趋势,经过微波处理的胶粉表现出类似“溶胀”的现象,孔隙增多,比表面积增大。采用凝胶渗透色谱试验对活化胶粉改性沥青的分子量进行研究,分析活化胶粉改性沥青的中大分子、中分子即小分子含量与改性沥青性能的关系,并对交互反应(IE)及交联作用(PE)与分子量的关系进行分析。结果表明,LMS与粘度及复数剪切模量的IE值呈正相关,即粘度或复数剪切模量的IE值增大,LMS值也相应增大,胶粉颗粒在沥青中的填充作用(即PE)对LMS的影响应当较小。采用差式扫描量热与热重试验分析活化胶粉改性沥青在升温过程中的质量变化及热稳定性,实验结果表明微波活化对胶粉改性沥青热重试验中质量损失及质量损失速率的影响较小。
[Abstract]:As one of the most important solid wastes in automobile industry, waste tires bring great pressure to the protection of ecological environment. In addition, the pressure of road traffic lies in a variety of road diseases closely related to it. Rubber asphalt, as a new material of environmental protection and high quality road engineering, has a good effect in consuming waste tire rubber powder and improving road traffic service level, but the poor storage stability restricts the popularization and application of rubber asphalt. Therefore, how to improve the storage stability of rubber asphalt, prolong the service life of asphalt pavement and improve the service level of asphalt pavement has become an urgent problem for workers in the industry. The production of modified asphalt after activation treatment of rubber powder provides a solution to the above problems. In this paper, waste rubber powder was activated by microwave activation method, rubber asphalt was prepared and filtered with asphalt screen to obtain rubber asphalt binder without rubber powder. Brinell viscosity (BV), dynamic shear Rheological (DSR) was used to study the road performance of rubber asphalt before and after activation of rubber powder. On this basis, the preparation process and parameters of high performance rubber asphalt prepared by activated rubber powder were recommended. The results show that when the microwave activation time of waste tire rubber powder is 90 s, the rubber powder modified asphalt has the best viscosity and high temperature stability. There is a linear positive correlation between the complex shear modulus of activated rubber powder modified asphalt and the corresponding IE. The higher the IE is, the greater the corresponding complex shear modulus is. The complex shear modulus of activated rubber powder modified asphalt has a linear positive correlation with the corresponding PE, and the higher the PE, the greater the corresponding complex shear modulus. The effects of microwave activation on the apparent morphology and specific surface area of waste tire rubber powder before and after activation were analyzed by scanning electron microscope (SEM) and specific surface area test. the modification mechanism was analyzed and studied according to the performance change of rubber powder modified asphalt before and after activation. The experimental results show that many micropores are added to the rubber powder by microwave radiation, and these micropores increase the specific surface area of the rubber powder. The rubber powder treated by microwave showed different degrees of agglomeration, the spacing between particles became smaller, the surface pores increased, and with the increase of microwave treatment time, the agglomeration phenomenon increased, and the surface pores tended to be dense. The rubber powder treated by microwave showed similar "swelling" phenomenon, the pores increased and the specific surface area increased. The molecular weight of activated rubber powder modified asphalt was studied by gel osmotic chromatography (GPC). The relationship between the content of medium and small molecules and the properties of modified asphalt was analyzed, and the relationship between the interaction reaction (IE) and crosslinked (PE) and molecular weight was analyzed. The results show that LMS is positively correlated with the IE value of viscosity and complex shear modulus, that is, the IE value of viscosity or complex shear modulus increases, and the PE value also increases correspondingly. The filling effect of rubber powder particles in asphalt (that is, PE) should have little effect on LMS. The quality change and thermal stability of activated rubber powder modified asphalt during heating were analyzed by differential scanning thermogravimetric test (DSC). The experimental results show that microwave activation has little effect on mass loss and mass loss rate in thermogravimetric test of rubber powder modified asphalt.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U414

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