基于表面能理论的老化温拌SBS改性沥青结合料的粘附性

在SBS改性沥青中添加Sasobit与Evotherm温拌剂制备得到温拌沥青,对3种SBS改性沥青进行旋转薄膜烘箱老化(RTFOT)与压力老化(PAV),采用接触角法检测了老化前后温拌SBS改性沥青与蒸馏水、甘油和甲酰胺等3种液体的接触角,探讨了短期老化与长期老化对温拌SBS改性沥青接触角的影响。基于表面自由能理论,得到了温拌SBS改性沥青的表面能及其色散分量和极性分量,研究了老化对温拌SBS改性沥青表面能的影响。结果表明:随着老化程度的加强,温拌SBS改性沥青与水的接触角逐渐增大,疏水性变化明显;原样与Evotherm温拌SBS改性沥青的总表面自由能及其分量均随着老化程度的加强呈降低趋势,其在短期老化阶段的表面自由能下降较为严重;经长期老化,Sasobit温拌SBS改性沥青的极性分量有增大趋势。

Adhesion of Aged SBS Modified Asphalt Binder Containing Warm Mix Additive Based on Surface Free Energy

Warm asphalt binders were prepared by adding Sasobit and Evotherm into SBS modified asphalt. The three SBS modified asphalt binders were aged using rotating thin film oven (RTFOT) and pressure aging vessel (PAV). The contact angles between aged SBS modified asphalt containing warm mix additive and distilled water, glycerol and formamide were detected by the sessile drop method. And the effect of short-term aging and long-term aging on contact angle of warm mix SBS modified asphalt containing warm mix additive with water was discussed. The total surface free energy and dispersive component and the polar component of SBS modified asphalt containing warm mix additive based on surface free energy theory. The influence of aging process on surface free energy of SBS modified asphalt containing warm mix additive was investigated. The results show that the contact angle between SBS modified asphalt containing warm mix additive and water is increasing and their hydrophobicity change significantly as they are aged continuously. The total surface free energy and its components will decrease with aging strengthening and decrease obviously at RTFOT aging stage. The polar component of SBS modified asphalt containing Sasobit warm mix additive has increasing trend at long term aging process.