彩色沥青老化组成及性能的研究

在150、163、180℃高温下,30h的老化时间内,采用沥青4组分(饱和组分、芳香组分、胶质和沥青质)分析法对彩色沥青老化时组成及使用性能的变化情况进行了测试实验。实验结果表明,在不同温度下,随着老化时间的延长,彩色沥青4组分含量的变化趋势基本一致：饱和组分、芳香组分和胶质各自的含量均逐渐减少,沥青质的含量则明显增加;另外,随着老化时间的延长和老化温度的升高,沥青软化点近似呈线性上升,针入度下降,延度则陡然降低。     

道路沥青及SBS改性沥青的紫外老化研究

采用紫外辐射试验对道路沥青和SBS改性沥青进行加速老化试验研究.利用老化前后的软化点、针八度、延度和四组分变化。分析了道路沥青的紫外线老化机理。结果表明:随紫外线老化时间的延长,道路沥青和SBS改性沥青软化点呈上升趋势、针入度和延度呈降低变化趋势,其中又以延度变化最为明显。经紫外线老化后道路沥青和SBS改性沥青的四组分也有变化,其中沥青质略微上升、芳香分略微降低,而饱和分和胶质变化不大。     

石油沥青及其组分吸氧老化中化学组成结构的变化

详细考察了单家寺和胜利直馏道路沥青(100号)及其组分在吸氧老化中化学族组成和平均结构参数的变化。结果表明,沥青的各组分变重,平均分子量增大;各种试样平均分子的总碳数、总环数、缩合指数和芳香度增加;胶质和沥青质组分变化最明显,是沥青中不稳定的组分。两种沥青相比,吸氧量较多的胜利沥青及其组分的变化明显高于单家寺沥青及其相应组分。     

石油沥青及其组分吸氧老化中化学组成和结构的变化

考察了单家寺和胜利直馏100号道路石油沥青及其组分在吸氧老化中化学族组成和平均结构参数的变化,结果表明,沥青的各组分变重,平均分子量增大;各种试样平均分子中的总碳数、总环数、缩合指数和芳香度增加;胶质和沥青质组分变化最明显,是沥青中最不稳定的组分;沥青吸氧确为缩合反应。两种沥青相比,吸氧量较多的胜利沥青及其组分的变化明显高于单家寺沥青及相应组分的变化。     

紫外线作用下道路沥青老化行为研究

为了研究紫外线老化下沥青性能变化,选取同种产地、不同标号的两种基质沥青以及两种常规改性沥青,分析基质沥青在不同紫外线老化后组分变化,研究四种沥青在不同时长紫外绒老化后的三大指标、DSR和BBR试验。结果表明,选用沥青老化后C/H值来评价同种来源基质沥青紫外老化性能是可行的,并可以通过使用DSR、BBR补充评价基质沥青和改性沥青紫外线老化后的高低温流变性能。     

陕西常用沥青老化组分变化规律及其影响

从2002年至今的沥青四组分试验结果显示,胶质含量较往年越来越少,在2011年甚至小于4%,但其常规指标仍然符合规范要求。针对这一现象选取其中2003年、2007年、2011年出厂的埃索90号沥青在不同老化时间之后的组分含量进行测试,结果发现2011年出厂的该沥青随老化时间的延长,胶质含量有很大程度的提高。尽管埃索90号沥青2011年出厂时的四组分含量与2003年相比差别很大,但是沥青在175℃左右温度下保温3h,组分变化后四组分含量与2003年出厂的该沥青老化后四组分含量差别缩小。最后从化学性质方面分析胶质含量变化的原因,并建议相关部门对埃索90号等沥青的长期性能给予足够关注。     

沥青老化过程中组分与微观形貌演变研究

为了探索沥青老化过程中组分与微观形貌的演变趋势,以5种不同油源的基质沥青为研究对象,对其进行薄膜烘箱老化试验和压力老化试验。随后对各沥青样品进行组分分离试验,并采用原子力显微镜对其微观形貌进行观测分析。结果表明:沥青老化过程中轻质组分向重质组分迁移,胶体指数呈下降趋势,且重质组分含量多的沥青组分变化较小;沥青表面微观形貌中的"蜂状结构"变得模糊,且表面粗糙度以及凸起部位最大高度下降。此外,胶体指数的下降也使得沥青更趋于凝胶结构,皮尔逊相关系数分析表明了沥青老化过程中组分的变化率与微观形貌的演变存在较强的正相关性,即组分指数变化率越大,微观形貌参数变化率也相应越大。     

沥青耐久性的预测方法

为预测沥青的耐久性要求有一种方法。开发这种方法将导致沥青规格的建立,以便改进沥青的质量。第一,该试验方法必须在鉴别沥青质量改变方面反应灵敏。第二,这些变化必须和实际使用的道路变化相关联。第三,这种质量规格必须纳入到随时间而变化到要求程度的范围。本研究通过比较以下试验的结果鉴别了几种对沥青质量变化敏感的方法。如①化学组成;②钒含量;③人工老化箱试验;④旋转薄膜烘箱试验的老化与户外老化试件的耐久性结果相比较。测量沥青的老化性能是可以通过测量粘度和沥青质含量随时间的延长来实现的。把每种试验方法对所有样品所得的结果都进行排列,与户外实际老化试验结果比较以显示鉴别沥青耐久性最好的方法。结果表明沥青钒含量与户外老化试验的结果高度相关。如果认为沥青中的组分不稳定性或高挥发性的因素是最小因素,则钒含量是一个预测沥青耐久性的最好参数。     

石油沥青抗老化性能研究

采用薄膜烘箱试验、低温吸氧试验、自然老化试验及反相气液色谱对国产典型的石油沥青及组分进行了老化和加速老化试验。根据沥青老化前后物化性质及其变化，如粘度比、吸氧量、凝胶渗析色谱峰扩展、族组成的变化、含氧基团的变化及老化综合指数等评价了国产沥青的抗老化性能。建立了沥青吸氧动力学模型。初步讨论了提高沥青耐久性的途径     

生物型沥青再生剂对老化沥青再生性能的影响

基于沥青老化及再生机理,自主开发了生物型沥青再生剂。室内模拟了沥青短期老化,依据沥青的老化程度确定了沥青再生剂的最佳添加量,并对沥青的再生效果进行了评价。试验结果表明:沥青的老化主要是由于组分移行造成,根据"相似相溶"原理,开发的生物型沥青再生剂能很好地改善老化沥青的组分重分布,调节沥青组分之间的相溶性,对老化沥青形成了良好的再生效果,再生沥青的性能可完全恢复至原样沥青的水平,其中以CO型沥青再生剂的再生能力最好。     

Performance evaluation of asphalt containing layered double hydroxides with different zinc ratio in the host layer

The effects of five layered double hydroxides (LDHs) with different zinc ratio on the physical and rheological properties, chemical components, and anti-UV aging performance of asphalt were evaluated. Results show that LDHs improve the deformation resistance of asphalt at high temperature. After UV aging, LDH-modified asphalts show the smaller changes of physical and rheological properties and chemical components in comparison with asphalt, indicating the improved UV aging resistance. By comparison, the LDHs with higher ratio of zinc in the layers have the more outstanding UV reflection ability, leading to a beneficial effect in improving UV aging resistance of asphalt.     

PHOTOOXIDATION OF CORBETT FRACTIONS OF ASPHALT

Oxidation of asphalt causes the degradation and failure of asphalt pavement. Due to the molecular complexity and relatively high molecular weight of asphalt, the oxidation mechanism is complicated by the interactions among the molecules of different types. To minimize the interactions, the asphalt sample was chromatographically separated into saturates, naphthalene aromatics, polar aromatics, and asphaltenes. These Corbett fractions were then oxidized under ultraviolet irradiation. Fourier-transform infrared spectroscopy was used to analyze the structural changes of the Corbett fractions during photooxidation. All Corbett fractions have shown significant spectral changes in the region of 3500 - 3100 cm^-1 characterized the stretching vibrations of hydroxyl or nitrogen-hydrogen groups, the peak around 1700 cm^-1 featured carbonyl groups, and in the region of 1320 - 1000 cm^-1 characterized the formation of sulfur-containing functional groups. Strong evidence has shown that sulfates are produced in the oxidation of asphalt. The formation of sulfates provides an essential explanation for the deterioration of asphalt pavement.     

微波对胶粉与沥青交互作用的影响

制备了不同微波时间处理的胶粉改性沥青,用凝胶渗透色谱测定了微波处理胶粉的甲苯抽出物的相对分子质量分布,采用溶剂抽提法将胶粉改性沥青的胶粉相与沥青相分离,用热重分析考察胶粉的交联度和橡胶烃含量的变化。结果表明,胶粉改性沥青的性质与其甲苯中的溶解度有明显的联系;经过5 min微波处理的胶粉,在沥青中的降解程度最高,胶粉在沥青中破碎形成带状结构,其制备的改性沥青的延度和针入度最高,软化点稍低;微波处理时间为5 min时胶粉中的部分大分子发生解交联,产生中等大小的分子,而继续延长微波处理时间到6 min,使5 min时形成的中等分子又重新与大分子反应连接。沥青中胶粉的交联度随微波时间延长先减小后增加,4 min时达到最大,而橡胶烃含量随微波时间延长先减小后增加,5 min时达到最小。胶粉交联度的减小有利于沥青中轻组分溶胀进入胶粉内部,使沥青中重组分相对含量提高,沥青变硬。而胶粉中降解产生的小分子,进入沥青后,使沥青变软,并且在胶粉和沥青之间形成界面层增强了二者的作用力。     

PHOTOOXIDATION OF CORBETT FRACTIONS OF ASPHALT

ABSTRACT

Oxidation of asphalt causes the degradation and failure of asphalt pavement. Due to the molecular complexity and relatively high molecular weight of asphalt, the oxidation mechanism is complicated by the interactions among the molecules of different types. To minimize the interactions, the asphalt sample was chromatographically separated into saturates, naphthalene aromatics, polar aromatics, and asphaltenes. These Corbett fractions were then oxidized under ultraviolet irradiation. Fourier-transform infrared spectroscopy was used to analyze the structural changes of the Corbett fractions during photooxidation. All Corbett fractions have shown significant spectral changes in the region of 3500 ? 3100 cm^?1 characterized the stretching vibrations of hydroxyl or nitrogen-hydrogen groups, the peak around 1700 cm^?1 featured carbonyl groups, and in the region of 1320 ? 1000 cm^?1 characterized the formation of sulfur-containing functional groups. Strong evidence has shown that sulfates are produced in the oxidation of asphalt. The formation of sulfates provides an essential explanation for the deterioration of asphalt pavement.     

Influence of asphalt chemical composition on moisture susceptibility of asphalt mixtures

To evaluate sensitivity of moisture damage resistance with chemical composition of asphalt, the adhesion energy, debonding energy as well as compatibility ratio of 69 asphalt-aggregate combinations were calculated with thermodynamical models. Pearson correlation analysis and regression analysis were carried out to correlate the relationships between asphalt chemical composition (saturates, aromatics, resins, asphaltenes, and wax) and moisture stability of asphalt mixture. The results showed that more resins and less asphaltenes in asphalt could lead to better moisture stability of asphalt mixture under dry and wet conditions, which can be effectively predicted by multiple regression models with different asphalt chemical components.     

SBS改性沥青机理研究

通过分析SBS改性沥青的红外光谱谱图、组分分布、DSC谱图。考察储存和加工工艺参数对SBS改性沥青性能稳定性的影响,深入探讨了聚合物改性沥青的机理。认为沥青改性以物理改性为主;SBS颗柱易吸收沥青中的饱和分,溶胀后的SBS极性与胶质相似;SBS颗粒与沥青有不完全相容性,SBS颗粒与沥青组分的亲和作用对沥青的相态转变产生影响;沥青组分对SBS的溶胀与吸附是一个动态的过程,它是沥青新胶体体系的形成和沥青聚集态结构改变的基础,这种动态过程对聚合物改性沥青的性能有很大影响。     

西部环境下沥青胶浆的性能评价

首先采用常规方法对基础沥青进行了性能评定,然后借助Superpave沥青结合料 试验设备与方法对国产克拉玛依AH-90沥青进行了PG分级并对7种胶浆进行了评价,通过评价确定了在西部地区使用的性能良好的沥青胶浆及其配合比,并总结出了在沥青中加入矿粉、水泥、纤维等对性能的改变,实践证明这种通过对胶浆性能的评价来预测其混合料的性能的方法是完全可行的.     

Preparation and evaluation of 30# hard grade asphalt

The preparation and evaluation of 30# hard grade asphalt by blending softening point hard deoil asphalt with several soft components were investigated. The results showed that the properties and proportions of blending soft components had a great influence on the properties of 30# asphalt. Chunfeng 70# asphalt and Maoming deoil asphalt were more suitable as blending soft components and their blended asphalt met the technical requirements of GB/T 15180-2010 when the proportion of hard deoil asphalt were 6–12% and 8–16%, respectively. PG grade results indicated that dynamic modulus of 30# asphalts at high temperature increased significantly, and antirutting ability was also improved notably, while the bending resistant ability at low temperature was slightly inferior to the high-grade asphalt. The results of mix performance tests showed that 30# hard grade asphalt had excellent anti–high-temperature deformation ability and preferable water stability compared with high-grade asphalts.     

道路石油沥青热稳定性能物化分析

通过对三种道路石油沥青老化前后试样进行元素分析、四组分分析、热重(TG)分析和红外光谱(FT-IR)分析,试验结果表明,沥青的热稳定性能主要体现在老化前后沥青中主要元素含量、组分组成及特征基团含量的变化,说明沥青的热稳定性能不仅与油源的资源属性密切相关,而且可通过干预沥青中主要元素的含量、化学组分的分布及特征基团的含量等生产出符合沥青宏观技术性能指标需求的合格产品.