Comparative Simulation Analysis Of Screening Methods For Recycled Asphalt Mixtures

Due to the many disadvantages of the traditional regeneration method of asphalt pavement,this paper proposes to use on-site plant mixed hot regeneration construction method to recycle a large amount of recycled asphalt mixture.The construction process of this method includes cleaning the road surface,milling the road surface,screening,metering,spraying regenerant,mixing,paving,and compaction,that is,using plant mixed hot regeneration method to achieve on-site asphalt pavement regeneration.Compared to traditional on-site thermal regeneration,on-site plant mixed thermal regeneration has added screening and weighing processes for recycled asphalt mixture,which can better ensure the gradation of recycled asphalt mixture and significantly improve the mixing rate of recycled asphalt mixture while ensuring the quality of regeneration.As a crucial part of on-site plant mixed hot recycling,screening directly affects the accuracy of the gradation of the recycled asphalt mixture and the quality of the paved road surface.Therefore,this article focuses on studying the relevant content that affects the screening efficiency of on-site plant mixed hot regeneration,and the specific research work is as follows:(1)I established simulation models for three screening methods and conducted comparative analysis through EDEM simulation software.By comparing the screening efficiency of these three screening methods at the same tilt angle,the most suitable screening method for recycling asphalt mixture is identified.The simulation analysis results show that:(1)under the same inclination angle,the screening efficiency of the cylindrical screen is higher than the other two screening methods;(2)When the cylindrical sieve is used for screening,the degree of particle agglomeration is smaller;(3)In actual production,the vibration of the relaxation screen and the linear vibration screen will shorten the service life of the machinery.Therefore,it is concluded that cylindrical sieves are more suitable for screening materials with cohesive characteristics such as recycled asphalt mixtures.(2)After determining the cylindrical screen as the most suitable screening method for recycling asphalt mixture,the two main parameters that affect its screening efficiency,namely tilt angle and rotation speed,were studied.The study found that:(1)as the tilt angle of the cylindrical screen gradually increases,its average screening efficiency shows a trend of first decreasing,then increasing,and then decreasing;(2)When the inclined angle of the cylindrical sieve is 20°,its screening efficiency reaches its maximum;(3)As the inclination angle increases,the degree of particle adhesion shows a trend of first increasing,then decreasing,and then increasing.(4)As the rotational speed of the cylindrical screen increases,its average screening efficiency shows a trend of first decreasing,then increasing,and then decreasing again;The degree of particle adhesion shows a trend of first decreasing and then increasing.