岩沥青/胶粉复合改性沥青流变及存储特性研究

Study on Rheological and High Temperature Storage Characteristics of Rock Asphalt/Rubber Powder Composite Modified Asphalt

选用青川岩沥青和胶粉作为改性剂共同对70号A级沥青进行复合改性。首先利用针入度系统试验对岩沥青掺量进行了优选;其次,利用频率扫描试验对复合改性沥青的高温流变特性进行了研究;接着,借助软化点差试验及温度扫描试验对经高温存储后的复合改性沥青离析情况及流变特性进行了分析;最后,利用微观试验设备对复合改性沥青进行了扫描电镜及红外光谱成像试验。结果表明:胶粉及岩沥青的加入都可大幅提高沥青的高温性能,使沥青变得黏稠,岩沥青可提高沥青的弹性成分,但对沥青的低温性能具有较强削弱;沥青的高温抗剪切能力、抗老化性能和高温存储效果显著增强。微观试验表明,复合改性沥青中大部分岩沥青及胶粉微粒互相独立存在,少部分岩沥青进入了胶粉微粒构成的微观网络系统,这对增强沥青的抗高温变形能力及抗老化性能具有积极作用,且岩沥青及胶粉的共同改性是以物理改性为主、存在少部分化学改性的物化复合改性体系。

Qingchuan rock asphalt and rubber powder were selected as modifiers to compound 70#asphalt. Firstly, the blending of rock asphalt was optimized by the needle degree system test, the high temperature rheological characteristics of composite modified asphalt were studied by the frequency scanning test;then, the high temperature rheological properties of composite modified asphalt were studied by frequency sweep test;then, the segregation and rheological properties of composite modified asphalt after high temperature storage were analyzed by means of softening point difference test and temperature sweep test;finally, SEM and FTIR imaging experiments were carried out on composite modified asphalt using microscopic test equipment. The results showed that both rubber powder and rock asphalt could greatly improve the high temperature performance of asphalt, and make the asphalt become thick.Rock asphalt could improve the elastic composition of asphalt, but reduce the low temperature performance of asphalt.The high temperature shear resistance, aging resistance and high temperature storage effect of composite modified asphalt were significantly enhanced. Micro test showed that most of the composite modified asphalt rock asphalt and rubber powder particles was independent of each other, a small number of rock asphalt entered into the micro network system composed by rubber powder particle to enhance the asphalt high temperature deformation ability and anti-aging properties,and the co-modification of rock asphalt and rubber powder was a physical-chemical composite modification system based on physical modification with a small amount of chemical modification.