TLA改性沥青及其混合料老化特性和机理研究

发布时间：2018-01-03 13:22

本文关键词：TLA改性沥青及其混合料老化特性和机理研究　出处：《广西大学》2015年硕士论文　论文类型：学位论文

【摘要】：特立尼达湖沥青(TLA)是天然形成的物质,其经过了亿万年地壳压力和温度的作用,已经充分氧化沉淀,性质稳定。TLA的掺入对普通石油沥青混合料路用性能(高温稳定性、低温抗裂性以及水稳定性)有明显改善作用。但是,掺入TLA对沥青及其混合料抗老化性能的研究较少,现有的老化评价体系对TLA改性沥青的适用性也有待探讨。因此,为了提高TLA改性沥青路面的使用寿命,进一步促进TLA改性沥青的推广应用与发展,本文着重对TLA改性沥青及其混合料的老化特性和机理进行深入研究。采用旋转薄膜烘箱(RTFOT)、压力老化仪(PAV)研究TLA改性沥青在不同老化温度、时间以及老化方式下三项常规指标、旋转粘度以及流变性能的变化规律。试验结果表明,三种老化因素均对TLA改性沥青各项性能有较为显著的影响,与基质沥青相比,不同老化方式下TLA改性沥青抗老化性能更为优异。采用动态剪切流变仪(DSR)对沥青老化前后的动态流变特性进行测试,并以64℃时的复合模量G*为参数建立沥青的动力老化方程,通过热力学方法比较两种沥青抗老化性能的差异。结果表明,TLA改性沥青具有较高的活化能,掺入25%TLA后活化能提高了12.8%,化学反应速率较基质沥青小,性质更稳定。通过红外光谱(IR)分析技术,对TLA改性沥青老化前后化学结构的变化进行分析,研究TLA改性沥青老化机理。结果表明,掺入TLA为物理改性,并没有产生新的特征吸收峰,TLA带入的萘官能团和季铵基团对沥青抗氧化性能有明显改善作用,改性沥青制备过程存在一定程度的老化,随着老化程度的加深羰基和亚砜指数均增大,相比之下TLA改性沥青增加幅度较小。从浸水马歇尔试验和劈裂疲劳试验入手,研究老化时间、温度及粗集料含量对沥青混合料老化性能的影响。结果表明,三种因素均对水稳定性和疲劳性能有显著影响,而粗集料含量多的混合料更容易加速老化的作用,疲劳裂缝更倾向于沿着内部空隙发展。
[Abstract]:Trinidad Lake Asphalt (TLA) is a natural form of the material, after millions of years of crustal pressure and temperature effect, fully oxidation precipitation, stable properties of doped.TLA on the performance of common asphalt mixture (high temperature stability, low temperature crack resistance and water stability) have obvious improvement. However, doping the study of TLA anti aging performance of asphalt and its mixture less, existing aging evaluation system on the applicability of TLA modified asphalt has yet to be discussed. Therefore, in order to improve the TLA modified asphalt pavement service life, further promote the development and application of TLA modified asphalt, this paper focuses on the in-depth study of aging characteristics TLA modified asphalt and its mixture and mechanism. The rotating thin film oven aging instrument (RTFOT), pressure (PAV) on TLA modified asphalt at different aging temperature, aging time and mode of three conventional means Standard, rotational viscosity and rheological properties were studied. Experimental results show that the three aging factors of TLA modified asphalt have remarkable influence on the performance, compared with matrix asphalt under different aging TLA modified asphalt anti-aging performance is more excellent. By using dynamic shear rheometer (DSR) test the dynamic rheological properties of asphalt after aging, and the composite modulus G* to 64 DEG C for the establishment of dynamic parameters of asphalt aging equation, difference by thermodynamic method anti aging performance comparison of two kinds of asphalt. The results show that the activation energy of TLA modified asphalt with high doped 25%TLA, the activation energy increased by 12.8%, chemical reaction the rate is better than the matrix asphalt, more stable in nature. By infrared spectroscopy (IR) analysis technology of TLA modified asphalt chemical structure changes before and after aging were analyzed on TLA modified asphalt aging mechanism. The results show that, The incorporation of TLA into physical modification, and did not produce new absorption peaks of naphthalene groups and quaternary ammonium groups into the TLA had a significant effect on improving the oxidation resistance of asphalt, modified asphalt preparation process has a certain degree of aging, are increasing with the aging extent of the carbonyl and sulfoxide index, compared with TLA asphalt increased to a lesser extent. From the immersion Marshall test and splitting fatigue test research of aging time, temperature and content of coarse aggregate material affect the aging properties of asphalt mixture. The results showed that all the three factors have significant influence on water stability and fatigue resistance, and the mixture of coarse aggregate content and more to accelerate the aging effect, fatigue cracks tend to develop along the inner space.

【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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