TLA/SBS复合改性沥青性能研究

Properties Research of TLA/SBS Composite Modified Bitumen

通过熔融共混的方式,将SBS(苯乙烯-丁二烯-苯乙烯嵌段共聚物)和不同掺量的特立尼达湖沥青(Trinidad Lake Asphalt,TLA)加入基质沥青中,制备TLA/SBS复合改性沥青。对TLA/SBS复合改性沥青的针入度、软化点、延度进行测试,研究改性后沥青的物理性能。采用动态剪切流变仪对改性前后沥青的流变性能进行检测和分析,采用热氧老化和PAV(压力老化测试)对改性前后沥青的老化性能进行研究分析。结果表明,加入湖沥青后,随着TLA掺量的增加,沥青针入度减小,软化点和延度先增大再减小。为了避免过高掺量的湖沥青对沥青延展性造成不利影响,应将湖沥青的掺入量控制在30%。TLA/SBS复合改性沥青复数模量和车辙因子增加,相位角减小,沥青的高温抗车辙变形能力得到提高。TLA/SBS复合改性沥青的残留针入度比、软化点变化和粘度老化指数下降,老化性能得到改善。

The TLA/SBS composite modified bitumen was prepared by adding SBS and different dosages of Trinidad Lake bitumen(TLA)into matrix bitumen by melt blending,and the penetration,softening point and ductility of TLA/SBS composite modified bitumen were tested,the physical properties of the modified bitumen were studied,the rheological properties of bitumen before and after modification were detected and analyzed by dynamic shear rheometer,and the aging properties of bitumen before and after modification were studied and analyzed by thermal oxygen aging and PAV aging.The results show that after the addition of lake asphalt,with the increase of TLA content,the penetration of asphalt decreases,the softening point and ductility increase first and then decrease.In order to avoid the adverse effect of excessive content of lake asphalt on asphalt ductility,the incorporation amount of lake asphalt should be controlled at 30%.The complex modulus and rutting of TLA/SBS composite modified bitumen increased,the phase angle decreased,and the high-temperature rutting resistance of bitumen was improved.The residual penetration ratio,softening point change and viscosity aging index of TLA/SBS composite modified bitumen decreased,and the aging performance was improved.