不同低温改性剂对沥青性能的影响及其作用机理研究

Study on Effects of Different Low-Temperature Modifiers on Asphalt Performance and Their Mechanisms of Action

摘要:

为研究不同类型低温改性剂对沥青性能的影响，以SBS改性沥青作为母体沥青，分别选取复合型、烷烃型、聚烯烃型（分别命名为LTM、SAS、XT）3种类型的低温改性剂，对母体沥青进行改性。通过沥青基本性能试验和流变性能试验，对3种低温改性沥青进行性能评价；然后，结合傅里叶红外光谱试验结果，分析3种低温改性剂的作用机理。研究结果表明：LTM低温沥青延度提升最大，达到了97.85 cm，且其110 ℃黏度较母体沥青降低了35.9%；SAS低温沥青软化点提升最大，较母体沥青提升了25.8%，达到了102.6 ℃；低温高频下，LTM低温沥青复数模量达2.5 MPa，其相位角响应与能量耗散机制趋近纯SBS特征，表现出均衡的疲劳寿命；FTIR分析表明，LTM与沥青相容性良好，其720 cm^-1与1 460 cm^-1处特征峰强度协调，无改性剂富集。

Abstract:

To study the impact of different low-temperature modifiers on asphalt performance, using SBS modified asphalt as the base asphalt, three types of low-temperature modifiers, namely composite, alkane and polyolefin (designated as LTM, SAS and XT respectively), are selected to modify the base asphalt. The performances of the three low-temperature modified asphalts are evaluated through the basic asphalt performance tests and rheological property tests. Then, combined with the results of Fourier transform infrared spectroscopy experiments, the action mechanisms of the three low-temperature modifiers are analyzed. The research results show that the ductility of LTM low-temperature asphalt improves the most, reaching 97.85 cm, and its viscosity at 110 °C is 35.9% lower than that of the base asphalt. The softening point of SAS low-temperature asphalt increases the most, rising by 25.8% compared to the base asphalt, reaching 102.6 ℃. At low temperatures and high frequencies, the complex modulus of LTM low-temperature asphalt reaches 2.5 MPa, and its phase angle response and energy dissipation mechanism approaches the characteristics of pure SBS, exhibiting balanced fatigue life. FTIR analysis indicates that the good compatibility is between LTM and asphalt, with coordinated peak intensities at 720 cm^-1 and 1 460 cm^-1, indicating no modifier enrichment.