Design And Experimental Study Of Ultrasound-assisted Dispersion Equipment For Crumb Rubber Modified Asphalt

In recent years,with the rapid development of national expressway,the demand of modified asphalt is increasing,and the quality requirement of modified asphalt is also increasing.Power ultrasound is a technology that uses ultrasonic energy to make certain states of objects or physical properties change.It has huge advantages in petrochemical fields such as wax prevention and viscosity reduction,sewage treatment,emulsification and demulsification.The technology is simple and direct,pollution-free,and has good economic benefits.When the ultrasonic wave is applied to the polymer modified asphalt,the mechanical action and cavitation effect can improve the dispersion of polymer in the matrix asphalt,promote the reaction between the modifier and the matrix asphalt,and improve the quality of the modified asphalt.In this paper,based on the analysis of the existing modified asphalt production equipment,the power ultrasonic integrated in the existing shear/mixing dispersion technology,the rubber powder modified asphalt ultrasound-assisted dispersion equipment structure design,from the heating mode selection,the size calculation of tank and agitator was analyzed.In addition,the ultrasonic-shear equipment of crumb rubber modified asphalt was simulated by Ansys Software,the asphalt movement,pressure change and gas volume fraction in the tank under the combined action of ultrasonic and agitation are analyzed,the motion of other areas is mainly affected by agitation.In the finite period,the volume fraction of the gas increases,the number of bubbles increases,and the cavitation intensity increases.The effect of asphalt viscosity on the change of gas volume fraction is studied by changing the viscosity of asphalt.When the viscosity of the system is 0.8 Pa s,cavitation will occur more easily.Based on the design and research of ultrasonic-assisted dispersion equipment for crumb rubber modified asphalt,the experiment of ultrasonic-assisted shear preparation of crumb rubber modified asphalt is completed,the test and analysis of penetration,softening point,ductility and viscosity of the samples show that ultrasonic has a good effect on improving the performance of crumb rubber modified asphalt,the mechanical action and cavitation effect of ultrasonic wave in crumb rubber modified asphalt can shear and disperse the crumb rubber particles,which makes the crumb rubber particles and asphalt more easily combined,improve the performance of crumb rubber modified asphalt.