Analysis of viscosity and composition properties for crumb rubber modified asphalt
Analysis of viscosity and composition properties for crumb rubber modified asphalt
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胶粉改性沥青粘度及组成特性分析
DOI：
10.1016/j.conbuildmat.2018.02.174
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发表时间：
2018-04-30
影响因子：
7.4
通讯作者：
Shen, Minghan
中科院分区：
文献类型：
--
作者：
Li, Peilong;Jiang, Xiuming;Shen, Minghan
制备胶粉改性沥青（RA）可以有效回收废旧橡胶，减少环境污染。为了确定RA的组成和影响其粘度的因素，针对不同的橡胶用量和橡胶尺寸，在不同的混炼温度和加工时间条件下制备了一些样品。对RA样品进行Brookfield粘度测试，分析这些因素对RA粘度的影响。根据不同温度下沥青的粘度值，采用阿伦尼乌斯方程求得RA的粘流活化能(En)。剖析了E eta 的变化规律。橡胶沥青的粘度可分为三部分：基础沥青的贡献（BE）、橡胶与沥青的相互作用效应（IE）和胶粉颗粒效应（PE），另外粘度定义为eta（RA）=eta（0）（1 + IE + PE）。为了分离PE，设计了筛分测试。采用Brookfield粘度计对RA样品和从胶粉中分离出的沥青样品进行旋转粘度测试。剖析了这些因素对橡胶沥青粘度组成参数IE和PE的影响。根据粘度定义，建立了橡胶沥青的粘度预测模型。结果和分析表明，随着橡胶含量的增加，RA的粘度值按指数增长模型不断增加。提高拌和温度与延长加工时间对橡胶沥青粘度有一定的等价性。但过高的温度或过长的时间可能会导致橡胶分子过度降解，从而导致RA粘度下降。随着胶粉用量的增加，原样和老化样品的RA E eta 均先上升后下降。峰值E eta 存在于橡胶含量10%～15%范围内。对于相同的橡胶用量，老化 RA 的 E eta 值超过原始样品的 E eta 值。对于采用相同类型和尺寸的橡胶粉制备的橡胶沥青样品，IE值与橡胶粉掺量呈线性关系，而PE值随着橡胶粉掺量的增加呈指数增长模型不断增加。在一定温度范围内，IE和PE值均与混合温度呈线性关系，与加工时间呈抛物线关系。所提出的预测模型能够反映橡胶沥青的粘度组成，并具有预期的拟合精度。 (C) 2018 Elsevier Ltd. 保留所有权利。
The preparation of crumb rubber modified asphalt (RA) shall effectively recycle waste rubber and abate environmental contamination. To ascertain the composition and the factors affecting the viscosity of RA, some samples were prepared in the case of different conditions of mixing temperature and processing time for different rubber dosage and rubber size. Brookfield viscosity tests were conducted on RA samples, and the impact exerted by these factors on viscosity of RA was anatomized. The visco-flow activation energy (En) of RA was acquired through adopting Arrhenius equation in line with the viscosity values of asphalt in the case of different temperatures. The changing regularity of E eta was anatomized. The viscosity of rubber asphalt can be split into three parts: the contribution of base asphalt (BE), rubber and asphalt interaction effect (IE) and crumb rubber particle effect (PE), and additionally the viscosity definition is proposed as eta(RA) = eta(0)(1 + IE + PE). To isolate the PE, the sieving test was designed. Rotary viscosity tests were conducted on RA samples and asphalt samples separated from crumb rubber through adopting Brookfield viscosity meter. The impact exerted by these factors on the viscosity composition parameters IE and PE of rubber asphalt was anatomized. In line with the viscosity definition, the viscosity prediction model of rubber asphalt was established. It is indicated from the results and analysis that the viscosity values of RA increase by the exponential growth model continuously with the increase of rubber content. There is a certain equivalence for rubber asphalt viscosity between raising mixing temperature and extending the processing time. But too high temperature or excessive time may result in excessive degradation of rubber molecules, which shall cause the decrease of RA viscosity. With the rising of the dosage of crumb rubber, E eta of RA for origin or aged samples both goes up first and thereupon drops down. And peak E eta exists in the range of rubber content from 10% to 15%. The E eta value of aged RA outstrips that of original sample for the same rubber dosage. For the rubber asphalt samples prepared through adopting the same type and size crumb rubber, the IE values show linear relation with the dosage of crumb rubber, while PE values increase by the exponential growth model continuously with the dosage of crumb rubber. Within a certain temperature range, IE and PE values both show linear relation with the mixing temperature, and show parabola relationship with the processing time. The proposed prediction model can manifest the viscosity composition of rubber asphalt and has an expected fitting precision. (C) 2018 Elsevier Ltd. All rights reserved.