Study On Mixing Flow Characteristics Of Different Asphalt Mixtures

The mixing fluidity of asphalt mixture determines the production quality of mixture and the engineering quality of asphalt pavement.Therefore,this paper studies the mixing fluidity of different asphalt mixtures,mainly for different asphalt dosage,different asphalt types and different grading types.The mixing fluidity and technical performance of asphalt mixture are studied.In this paper,Zhonghai 70# petroleum asphalt is used as matrix asphalt,limestone is used as aggregate to prepare crushed stone and mineral powder through rolling process.Six kinds of asphalt with different properties are selected: 70# matrix asphalt,Evotherm asphalt,SBS modified asphalt,etc.were selected.Five gradation types such as AC-13,OGFC-13,ATB-25 are selected.The asphalt content used were ω =2、4、5、6、8%(oil ratio).The mixing flow characteristics of different asphalt mixtures were carried out by using the variable speed mixing method through the variable speed mixing power test device developed by the research group.The test results show that the power test error of the mixing test device is less than 5%,and the test data is stable and reliable,which can be used to characterize the mixing power of asphalt mixture;the higher the mixing temperature is,the smaller the mixing rate is,the less the mixing power is consumed,and the easier the asphalt mixture is to be mixed;the mixing rheological model of asphalt mixture obeys the linear Bingham viscoplastic model,and the model is linear and oblique The ratio represents the mixing viscosity of the mixture,and the intercept reflects the internal plastic limit.The mixing and workability index can be defined as the reciprocal of the model straight line to the area of the mixing rate,and the viscoplastic flow parameters are comprehensively considered in theory.In this paper,the influence of different asphalt content,different asphalt types and different grading types on the mixing and workability of the asphalt mixture is analyzed,and the analysis results show that: The type of gradation affects the mixing plastic limit.The coarser the aggregate is,the greater the mixing plastic limit is,but the effect on the mixing viscosity is very small.The type and amount of asphalt have influence on mixing plastic limit and mixing viscosity.The thicker the asphalt is,the larger the amount is,the larger the mixing flow parameter value is,and the worse the workability is.