沥青胶浆粘度及流变特性的影响因素研究

Research on Viscosity and Rheological Properties of Asphalt Mortar

选用AS-70#基质沥青、SBS改性沥青与闪长岩、石灰岩两种矿粉,制备六种类型五种粉胶比的沥青胶浆,通过室内试验,测试沥青种类、矿物种类、粉胶比、温度对沥青胶浆粘度的影响,以及不同温度、剪切速率下沥青胶浆的流变特性。研究结果表明:相比于石灰岩矿粉,含闪长岩矿粉的沥青胶浆粘度更大,且同等条件下,改性沥青胶浆的粘度变化比基质沥青胶浆更快。沥青胶浆粘-温变化呈现半对数函数关系,不同粉胶比的同种沥青粘-温敏感性基本相同,当温度较低时,沥青胶浆的粘度随粉胶比变化显著,粉胶比越大胶浆粘度越大。G*/sinδ值随温度的变化呈现指数关系,当温度达到70℃时沥青胶浆失去使用功能;不同的剪切速率对基质沥青胶浆粘度的影响不明显,而改性沥青胶浆随剪切速率的增大而逐渐减小。

Six kinds of asphalt mortar with five ratios of powder to binder were prepared by using AS-70# matrix asphalt,SBS modified asphalt and diorite,limestone. The influence rule of asphalt type,mineral type,ratio of powder to binder and temperature on the viscosity of asphalt mortar and the rheological properties of asphalt mortar at different temperature and shear rate were researched. The results show that,compared with limestone mineral powder,the asphalt mortar with diorite ore powder has greater viscosity. And under the same conditions,the viscosity of modified asphalt mortar is faster than that of matrix asphalt mortar. The viscosity-temperature variation of asphalt mortar presents the semi-logarithmic function rule and the viscosity-temperature sensitivity of the same asphalt is basically the same. When the temperature is low,the viscosity of asphalt mortar changes significantly with the ratio of powder to binder,and the bigger the ratio of powder to binder,the bigger the viscosity of asphalt mortar. The value of G*/sinδ shows an exponential relationship with temperature and when the temperature reaches 70 ℃,the asphalt mortar loses its function. The effect of different shear rate on the viscosity of matrix asphalt mortar is not obvious,but the modified asphalt mortar gradually decreases with the increase of shear rate.