论文部分内容阅读
为了探索应力吸收层改性沥青热老化后的微观性能,选取90#基质沥青,加入一定比例SBS、SBR、稳定剂和糠醛抽出油分别形成改性沥青,进行旋转薄膜烘箱试验和压力老化试验分别得到短期老化和长期老化状态下的沥青样品。采用凝胶渗透色谱试验、差示量热扫描试验和热重试验对改性沥青分子量的变化和随温度变化引起的热性质变化进行研究。分析结果为:单掺SBR的改性沥青样品结构最不稳定,耐老化性能最差;稳定剂组和应力吸收层改性沥青老化过程中大分子的分解和小分子的聚合得到抑制,温度稳定性得到提高,而应力吸收层改性沥青低温延度增大,综合性能更能满足实际工程需要。热分析结果表明:除SBR改性沥青外,改性沥青样品短期老化阶段热晗较长期老化阶段小,短期老化阶段结构相对稳定,发生分解反应少于长期老化阶段。沥青在升温过程中质量损失主要分为小于200℃、200℃~420℃及420℃~550℃三个阶段,第三个阶段反应最剧烈,质量损失速率最大。研究结论可为应力吸收层改性沥青的制备与路用性能提供参考。
In order to explore the micro-properties of the stress-absorbing layer modified asphalt after heat aging, 90 # asphalt was selected and a certain proportion of SBS, SBR, stabilizer and furfural were extracted to form modified bitumen respectively. The rotating film oven test and pressure aging test Bitumen samples were obtained for short-term aging and long-term aging. The gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetry (TGA) were used to investigate the changes of molecular weight and the thermal properties of modified bitumen as a function of temperature. The results showed that the structure of modified bitumen with single SBR was the most unstable and the aging resistance was the worst. The degradation of macromolecules and the polymerization of small molecules during the aging of modified bitumen and stabilizer were restrained and the temperature was stable The property is improved, while the stress absorption layer modified asphalt low temperature ductility increases, the overall performance to better meet the needs of the actual project. The results of thermal analysis show that except for SBR modified bitumen, the short-term aging stage of modified bitumen sample is shorter than that of long-term aging stage, while the structure of short-term aging stage is relatively stable with less decomposition reaction than long-term aging stage. The mass loss of asphalt in heating process is mainly divided into three stages of less than 200 ℃, 200 ℃ ~ 420 ℃ and 420 ℃ ~ 550 ℃. The third stage has the most severe reaction and the mass loss rate is the highest. The conclusions of the study can provide reference for the preparation and road performance of modified asphalt with stress-absorbing layer.