Comparative Study On Durability Of Different Composite Modified Asphalt Mixture

The frequency and service life of asphalt pavement increases with the rapid development of transportation in our country.With the increase of service life of asphalt pavement and the influence of various adverse environments,how to increase the durability of asphalt mixture and increase the service life of asphalt pavement has become an important research direction.The durability of asphalt mixture mainly includes aging durability,plastic durability and fatigue durability.Asphalt mixture aging will make asphalt pavement brittle and reduce its resistance to low temperature stability and water stability.Unrecoverable plastic deformation of asphalt mixture at high temperature will cause great damage to asphalt pavement,and for a long tired,asphalt mixture of asphalt pavement will produce a surface rupture,etc.Single modifier has certain effect on improving the durability of asphalt mixture,but its ability to resist aging,plastic deformation,fatigue and other durability is relatively poor when the service life is too long or the environment is extremely harsh.Therefore,three kinds of composite modified asphalt mixtures,SBS,SBR and rubber powder were used in this study,and each two of them were pairwise compounded.SBS modifier has a good comprehensive performance,while SBR modifier has a good low temperature performance and bonding performance,rubber powder has a good high temperature performance and a good resistance to external damage.In terms of gradation,the durability of different kinds of asphalt mixtures was analyzed.AC-13,AC-16 and AC-20 are used in this test to prepare asphalt mixture.The durability of different kinds of asphalt mixtures was compared and analyzed.In terms of aging durability,the changes of high-temperature stability,low-temperature stability and water stability during the aging process of three kinds of composite modified asphalt mixtures were analyzed by observing the dynamic stability,bending strain,TSR and other indicators.In the aspect of plastic deformation durability,the ability of different composite modified asphalt mixtures to resist plastic deformation was analyzed by observing the deformation amount of different asphalt mixtures changing with time.In the aspect of fatigue durability,the fatigue characteristics of different asphalt mixtures were analyzed by testing the fatigue times of different asphalt mixtures.The conclusion has certain practical and useful meaning in improving the durability and increasing the service life of asphalt pavement.