高黏改性沥青的低温性能及黏附特性研究

Research on Low Temperature Performance and Adhesion Characteristics of High Viscosity Modified Asphalt

高黏沥青的低温与黏附特性是保证透水沥青路面服役功能的关键性能。为准确表征高黏改性沥青的低温抗裂与黏附性能,采用劲度模量、m-值、综合柔量参数Jc对比评价了高黏沥青的低温松弛与黏弹特性。基于表面能(SFE)理论开展了高黏沥青、集料的接触角试验,以黏附功、剥落功、能量比为指标评价了高黏沥青-集料体系的黏附特性与水稳定性。从微观尺度进行原子力显微镜(AFM)试验,分析高黏沥青的形貌特征及粗糙状况,结合微观黏附力描述其黏附特征。结果表明:大掺量高黏改性剂导致沥青的黏性成分减小,松弛能力降低,低温性能大幅降低,Jc值、劲度模量和m^(-)值表现出一致性规律;SBS与HVA-U的复合改性作用大幅改善了沥青的黏附性能,但相对降低了沥青-集料体系的水稳定性;高黏沥青的AFM高度图呈现数量多、尺寸小、高度差小的蜂状结构,其微观黏附力与黏附功具有强相关性。

The low-temperature behavior and adhesion of high viscosity asphalt(HVA)are critical properties to ensure the serviceability of the porous asphalt pavement.To accurately characterize the low-temperature performance and adhesion of HVA,the low temperature relaxation and viscoelastic characteristics of HVA are firstly assessed by comparing the stiffness modulus,m-value,and comprehensive flexibility parameter J..The adhesion properties and water stability of high-viscosity asphalt-aggregate system are evaluated by conducting the contact angle tests regarding high-viscosity asphalt and aggregate,which is based on Surface Free Energy(SFE)theory,with employing indicators such as adhesive work,peeling work and energy ratio.The morphological characteristics and roughness of HVA are examined by utilizing microscopic AFM tests,and the adhesion in conjunction with microscopic adhesion force are described accordingly.The results indicate that a high dose of high viscosity modifier reduces the viscosity behavior,relaxation capacity and low-temperature performance of asphalt,and that Je,stiffness modulus and m value show a consistency rule.The compound modification with SBS and HVA-U remarkably improves the adhesion of asphalt,but relatively degrades the water stability of asphaltaggregate system.Further,the large quantity,tiny size,and little height difference of the bee structures are appeared in the AFM height images of the HVA,and the microscopic adhesion force is strongly correlated to the adhesion work.