Mechanism Of DCLR Modified Asphalt And Preparation Of Mixture

Direct Coal Liquefaction Residue(DCLR),as a by-product of the clean coal utilization process,has the possibility of development as a road asphalt modifier.According to the material characteristics of DCLR,the process conditions and modification mechanism of modified asphalt are explored,which can establish basic research for the promotion of DCLR modified asphalt.First,the paper studies the preparation process of DCLR modified asphalt and evaluates and characterized its properties.By exploring the influence of different process conditions on the properties of modified asphalt,the best process conditions of DCLR modified asphalt are the mixing temperature of150℃,DCLR mixing amount of 8%,DCLR particle size of 60～80 mesh,and shear mixing method.Through performance evaluation,it is found that DCLR can improve the high temperature and anti-aging properties of asphalt,and reduce its low temperature performance.Secondly,the paper explores the mechanism of DCLR modified petroleum asphalt,with different cascade solvent dissolved DCLR,extraction separation of n-hexane insoluble toluene soluble asphalt(A),toluene insoluble tetrahydrofuran soluble,namely asphalt(PA)and tetrahydrofuran insoluble(THFIS),and then separately with petroleum asphalt.The results show that A is the most important component of DCLR modified petroleum asphalt;PA can effectively improve the high temperature performance of matrix asphalt,but largely damage the extension of asphalt material;THFIS is harmful to asphalt modification,greatly damage the rheological energy of asphalt.Obviously,the modification of DCLR is the result of the coordinated action of various components.Thirdly,the composition change and molecular structure by family composition analysis,infrared spectrograph and thermal weight analysis show that the appropriate ratio in asphalt and the corresponding chemical change.DCLR is similar.The thermal weight analysis shows that the content of high temperature resistance in the modified asphalt is improved.Finally,the asphalt mixture is tested with AC-20 grade,and the optimal asphalt rock ratio is 4.3%.The results show that DCLR can improve the high temperature stability and water temperature qualitative of the asphalt mixture,but has little impact on its low temperature performance.