废旧橡胶粉改性沥青自愈合性能研究毕业论文
2021-03-23 22:55:02
摘 要
随着汽车数量的不断增长,不但交通荷载量剧增,使得路面的压力愈来愈大,而且废旧轮胎这一固体废弃物问题也越来越严重。考虑到废旧轮胎这一固体废弃物本身就很难处理,并且设计一种长寿命的沥青路面也迫在眉睫,如何很好地解决这两个问题的意义十分重大。将废旧轮胎制成废旧橡胶粉,并利用废旧橡胶粉对沥青进行改性,不但能大幅度提高沥青的性能,而且还能很好地解决废旧轮胎这一固体废弃物问题。为了实现这一目标,深入研究废旧橡胶粉改性沥青材料自愈合能力内在机理并找到相应的评价方法显得尤为重要。
本研究利用动态剪切流变仪(DSR),选取TL-70基质沥青、自行车40-60目废旧橡胶粉改性沥青、小轿车40-60目废旧橡胶粉改性沥青、卡车40-60目废旧橡胶粉改性沥青作为研究对象,对它们的自愈合能力进行了评价和分析。
本文首先对上述四种沥青分别进行了温度扫描、频率扫描测试,对比分析了不同种基质沥青与不同种废旧橡胶粉改性沥青的基本动态流变性能的变化情况。三种废旧橡胶粉的加入均能使模量增大,相位角减小。通过实验数据及相应的图可以知道,四者的复合剪切模量数值均随着温度的升高而减小,而相位角却随着温度的升高而增大。复合剪切模量数值随着荷载作用频率的增大而增大,并且其对数值与荷载作用频率的对数值有着良好的线性关系。
最后,通过选取损伤速率和愈合指数作为参照评价标准,对四种沥青进行了疲劳—愈合—再疲劳试验,研究了沥青的自愈合性能。结果表明,在重复荷载外力作用下,除基质沥青的抗疲劳性能降低,愈合指数HI变小,自愈合能力变弱外,其它三种废旧橡胶粉改性沥青的后面几次的疲劳性能均比第一次好,自愈合能力也是逐渐变弱的。由于废旧橡胶粉改性沥青在第一次疲劳加载和间歇过后,废旧橡胶粉发生了进一步的溶胀,使得疲劳性能变好。由于重复荷载的作用,沥青内部发生了疲劳破坏,使得自愈合能力逐渐变弱。
关键词:废旧橡胶粉改性沥青;疲劳—愈合—再疲劳测试;自愈合。
Abstract
With the increasing in the number of locomotive, not only the traffic load is becoming heavier and heavier, and the pressure of pavement is becoming heavier and heavier, but also the problem of waste tires is becoming more and more serious. Considering the waste tires is difficult to deal with, and it is very useful to design a durable asphalt pavement with long life, how to solve these tow problem is very meaningful. Using rubber powder to modify the asphalt not only can greatly improve the performance of asphalt, and also can deal with the problem of waste tire well .In order to achieve this goal, it is important to have an intensive research on self-healing capacity of rubber asphalt and find a standard to evaluate this property.
The study chose standard unmodified asphalt TL—70, bicycle rubber asphalt, car rubber asphalt, truck rubber asphalt as the objects of study, and their self-healing capacities were evaluated and analyzed by dynamic shear rheometer (DSR).
Firstly, the temperature scanning test and frequency scanning test were taken on the four asphalts in this study. All of three kinds of rubber can make modulus increases, and also can make phase angle decreases. Through the experimental data and the figure, results show that the complex shear modulus value of then decline with the temperature rising, but the phase angle increases. The complex shear modulus increases with loading frequency rising, and the log of complex shear modulus has a good line relationship with that of loading frequency.
Finally, to study the self-healing properties of the four asphalts, the fatigue-healing-fatigue tests were performed on them by choosing the damage rate and the healing index as an evaluation standard, The results show that under the repeated loading, except the matrix asphalt, all of three asphalts have better anti-fatigue performance than the first loading, but all of their self-healing capacity became week gradually. After the first fatigue-healing, the waste rubber powder swelled further, which made the fatigue performance better. As a result of the action of repeated load, fatigue damage occurred in asphalt, which made the self-healing capacity become weak gradually.
Key Words: rubber asphalt; fatigue-healing-fatigue tests; self-healing.
目 录
中文摘要 I
Abstract II
第一章 绪论 1
1.1课题研究目的及意义 1
1.1.1课题研究目的 1
1.1.2课题研究意义 1
1.2 研究现状 2
1.3 研究内容以及采用的技术路线 3
1.3.1研究内容 3
1.3.2采用的技术路线 4
第二章 原材料与试验方法 5
2.1原材料 5
2.1.1沥青 5
2.1.2 废旧橡胶粉 5
2.2 试验方法 5
2.2.1试验原理 5
2.2.2实验仪器 7
2.2.3样品制备 8
第三章 废旧橡胶粉材料性能分析 10
3.1 橡胶粉扫描电镜分析 10
3.1.1不同废旧橡胶粉SEM图对比 10
3.1.2不同废旧橡胶粉扫描电镜表面元素分析EDS对比 10
3.2橡胶粉综合热分析 14
第四章 废旧橡胶粉改性沥青动态流变性能 16
4.1基本理论 16
4.2温度扫描 17
4.3频率扫描 18
第五章 废旧橡胶粉自愈合性能测试及评价 20
5.1疲劳测试 20
5.2疲劳——愈合——再疲劳测试 21
5.3废旧橡胶粉改性沥青自愈合性能评价 27
第六章 结论与展望 28
6.1主要结论 28
6.2展望 28
参考文献 29
第一章 绪论
1.1课题研究目的及意义
1.1.1课题研究目的
目前,我国废旧轮胎的产生量在1亿条以上,随着汽车工业的快速发展,废旧轮胎的产生量还将不断增加。在综合利用方面,约有46%的废旧轮胎被用于制造再生胶和胶粉,两者都可以作为生产橡胶制品的原材料,而胶粉少量直接应用于沥青改性,大部分用于生产再生胶,这对减少生胶使用量、降低资源消耗、节约生产成本都起到了一定的促进作用[1]。在国家“十三五”计划中,将轮胎翻新业、再生橡胶业、橡胶粉热裂解业列为“十三五”期间行业发展的主要任务[2]。
将废旧轮胎加工成橡胶粉是国际通用的废旧轮胎再生处理方式,其中废旧轮胎橡胶粉在公路行业中的应用是废旧轮胎处理的主要途径之一。废旧轮胎橡胶粉主要的化学成分还是天然橡胶和合成橡胶(如丁苯橡胶、顺丁橡胶),还有硫、碳黑、氧化硅、氧化铁、氧化钙等成分。以上这些成分都是良好的沥青改性剂,能够改善沥青的高低温性能、抗老化性能、抗疲劳性能,起到减薄路面、延长路面使用寿命、延缓反射裂缝、减轻行车噪声、优良的冬季柔性等作用。因此,废旧橡胶粉在公路行业中有着十分重要的现实意义。