Study On Phase Mixing Technology And Experimental Device Of Asphalt Mixture

Asphalt mixture is composed of coarse,fine aggregate,mineral filler and asphalt.Commonly used mixing process is coarse,fine aggregate dry mix,and then add mineral and asphalt continue to mix for a certain time,mixing time determined by the trial mixing.The performance of asphalt mixture is affected by many factors,and many scholars have made an in-depth study on the performance of the mixture,the performance of raw materials and the effect of paving compaction on the performance of the mixture.How does the mixing process affect the performance of the asphalt mixture is less studied.In order to ensure the mixing quality of the mixture,improve the production efficiency of the agitator,and provide the reference for the engineering practice.In this paper,the optimum mixing time and material addition process and mixing time were studied.The subject relies on the double-horizontal shaft mixer project of the China Railway Bureau.The mixing process was studied by means of theoretical analysis and experimental study.In order to simulate the mixing process of the mixing plant,the research group developed the same double-shaft mixer as the mixer structure and the stirring principle used in the solid engineering.The mixing process test was carried out using this mixer.Through the establishment of the stirring model,the rolling rule of the aggregate particles under the action of the agitator was analyzed.According to the mixing mechanism of asphalt migration in the process of rolling,the relationship between the mixing uniformity and the number of rolling elements is obtained under the condition that the migration rate of the asphalt is decreasing at a certain rate.According to the formula curve,in the mixing process,the rolling times of particles are related to the particle size.The rolling times of the slag are more than fine aggregate,and the rolling times of fine aggregate are more than coarse aggregate,which results in the change of the oil film thickness.This relationship results in different film thicknesses attached to the surface of the particles with different particle sizes.The rolling relationship between the particles with different size during the mixing process was obtained by the circular circle model with different diameter.According to theresults of the study,a phase mixing technology is proposed.This process can make the thickness of the surface asphalt film uniform by using the proper addition order between the coarse aggregate,the fine aggregate,the mineral powder and the asphalt.In order to verify the phase mixing technology,the AC-16 grade compound was studied by using the developed mixer.The results show that the use of phase mixing technology,can improve the quality of asphalt mixture and equipment production efficiency,reduce the amount of asphalt,compared with the traditional mixing process asphalt dosage can be reduced by about 5%,and reduce the mixing time of about 30%.