Research On Storage Stability Of Pyrolytic High Volume Crumb Rubber Modified Asphalt

Crumb rubber modified asphalt attracts high attention in the road building industry with its good high & low temperature performance,anti-fatigue performance,and special role in environmental protection,i.e.solving “black pollution”.However,the storage stability of crumb rubber modified asphalt prepared by traditional low temperature mixing/shear process is poorer,restricting the application of crumb rubber modified asphalt in engineering.Therefore,the study on the storage stability of crumb rubber modified asphalt is of far reaching significance.This paper effectively reduces the size of crumb rubber power particles,enhance the compatibility of crumb rubber power and asphalt and improve the storage stability of crumb rubber modified asphalt by high temperature.Meanwhile,in order to make full use of waste resources,this paper tries to adopt a high content of rubber powder.In this paper,traditional rubber asphalt and high volume crumb rubber modified asphalt with different processing conditions(pyrolysis temperature and pyrolysis time)were made,and the difference of softening point on polymer segregation test,segregation ration on DSR test and the difference of four components and fluorescence microscopic structure between upper and lower sections were adopted to evaluate the storage stability of modified asphalt.The influence of processing conditions(pyrolysis temperature and pyrolysis time)and the dosages of PE on storage stability were comparatively analyzed.This paper discussed the correlations of grade of base asphalt,viscosity,fluorescence microscopic structure,rubber powder solubility,and colloid instability coefficient Ic to storage stability.Test results show that,pyrolytic crumb rubber modified asphalt is better than traditional rubber asphalt in hot storage stability,and has the best storage stability under the processing conditions of 250°C and one hour.The grade of base asphalt has an influence on storage stability,but not distinct.Through high-temperature pyrolysis,rubber powder of pyrolytic crumb rubber modified asphalt is smaller in size,more uniform in size distribution,greater in solubility,and more compatible with asphalt.The dosages of PE have a direct correlation with storage stability of PE/crumb rubber compound modified asphalt,and storage stability of pyrolytic crumb rubber modified asphalt could be improved over a limited range of dosages.