沥青老化行为及其机理研究

Research on Aging Behavior and Mechanism of Asphalt

为了系统研究SK-90#基质沥青与SBS改性沥青老化前、后性能变化,选取原样沥青(SK-90#、SBS)及回收沥青(R-90#、R-SBS)作为研究对象,通过DSR、BBR试验比较两种沥青在不同状态下性能差异,并根据微观相态结构、四组分、红外光谱试验探究差异形成之因。试验结果表明:相比于原样沥青,回收沥青低温抗变形能力降低,而高温抗变形及抗疲劳能力均明显增强,且两种状态下SBS改性沥青的性能均更优,说明其具有更好的耐久性质; R-SBS零散的荧光现象表明SBS改性剂发生裂解变成了更小的颗粒,SBS改性剂的裂解增加了沥青的流动性和温度敏感性,使R-90#与R-SBS相位角δ的变化情况出现了较大差异;此外,四组分及红外光谱的试验结果表明沥青在老化过程中饱和分因高温而挥发,芳香分因老化向胶质转化,并最终因氧化作用转化为沥青质,其中很多短链碳氢化合物经加成、聚合生成了更多的长链化合物。

To study the performance change of SK-90#asphalt and SBS modified asphalt before and after aging,new asphalt and reclaimed asphalt were used as the research object.In this paper,DSR and BBR tests were used to compare the performance difference between the two kinds of asphalt in different states,and the reasons of differences were explored according to the microscopic phase structure,four components and infrared spectroscopy tests.The results show that the low temperature anti-deformation ability of reclaimed asphalt is lower than that of the original asphalt,and the high temperature anti-deformation and anti-fatigue ability of the asphalt are obviously enhanced.The performance of SBS modified asphalt is better in both states,indicating that it has better durability.The scattered fluorescent phenomenon of R-SBS shows that SBS modifier is cracked into smaller particles.The cleavage of SBS modifier increase the flowability and temperature sensitivity of asphalt,nd lead to the big difference of phase angleδbetween R-90#and R-SBS.In addition,the four-component and infrared spectra testes results indicate that the asphalt saturated phenol volatilize because of high temperature,and aromatic phenol transform to the glue in the process of aging.Ultimately,the aromatic phenol and glue turn into asphaltenes due to oxidation,and much short-chain hydrocarbons are added and polymerized to generate more long-chain compounds.