Study On The Modification Mechanism And Modification Effect Of Resin And Elastomer High Viscosity Modified Asphalt

High viscosity modified asphalt is one of the important components of drainage asphalt pavements.In order to investigate the modification mechanism and modification effect of high viscosity modified asphalt,scholars have conducted a lot of research on the chemical composition and rheological properties of various types of modified asphalt(resin,elastomer,rubber,nano,etc.),but there is a lack of systematic and comparative effect evaluation studies.In this paper,the chemical composition of two types of high viscosity asphalt(resin and elastomer)has been studied by transmission electron microscopy(TEM),gel permeation chromatography(GPC),differential scanning calorimetry(DSC),and the rheological properties of the two types of high viscosity asphalt.The microstructure composition,molecular weight size,thermal stability and chemical composition of the asphalt were analyzed by transmission electron microscopy(TEM),gel permeation chromatography(GPC),differential scanning calorimetry(DSC)and infrared spectroscopy(ATR-FTIR),respectively.The microstructure composition,molecular weight size,thermal stability and chemical composition were analyzed.The high temperature deformation resistance(temperature scan,multi-stress creep recovery test,zero shear viscosity),medium temperature fatigue resistance(LAS fatigue test)and low temperature cracking resistance(low temperature BBR test)of the two high viscosity modified asphalts were investigated immediately.Among them,different test frequency intervals and different models were fitted for zero shear viscosity(ZSV)to determine the best test frequency interval and fitting model for high-viscosity asphalt,and to evaluate the ZSV of two high-viscosity asphalts.In order to describe the viscosity/modulus variation of the 2 high viscous asphalts,a wide temperature domain study was conducted and it was found that the influence of the moment of inertia was more serious at high temperature,while the influence of the moment of inertia could be attenuated by stress control(50 Pa),which could also be verified by fitting the frequency spectrum and the master curve,and finally the modulus variation of the 2 high viscous asphalts under wide temperature domain was evaluated by stress control.Finally,a series of performance studies were conducted on the 2 high-viscosity asphalt mixtures,and the conclusions were consistent with those obtained for asphalt binders.The main research results are as follows:(1)from the chemical composition point of view,resin-based modified asphalt through internal crystallization increases the hardness of asphalt,thereby increasing the viscosity of asphalt,elastomeric modified asphalt by itself and asphalt to form a three-dimensional elastic mesh structure to increase the elasticity of asphalt,to achieve the effect of viscosity;.(2)from the rheological point of view,resin-based high-viscosity modified asphalt has a large modulus,can resist rutting deformation,low-temperature cracking resistance is poor,high temperature crystallization melting,asphalt mobility increased,can achieve the effect of warm mix,and elastomeric high-viscosity modified asphalt has a high elastic recovery capacity,good resistance to deformation,can improve the low-temperature cracking resistance,but the high temperature due to increased viscosity and resulting in poor asphalt flow,construction and ease of poor.(3)The recommended test frequency range is 0.01-100 Hz for high viscosity asphalt ZSV test,for high viscosity asphalt ZSV fitting results,Cross model fitting ZSV value will be greater than the Carreau model,but the evaluation effect of the 2 models is consistent,resin high viscosity modifier on the ZSV improvement is more obvious,but with the increase in the amount of admixture and the existence of the upper limit,elastomeric high viscosity asphalt asphalt with increasing admixture,the elastic mesh structure is more robust and the ZSV increases.(4)When conducting wide temperature domain tests,adopting stress control(50 Pa)instead of conventional strain control can attenuate the effect of moment of inertia,eliminate the phenomenon of plateau area of storage modulus of low viscosity asphalt,and produce more accurate measurement results on phase angle.(5)The performance test study of the 2 high-viscosity asphalt mixtures showed that resinous high-viscosity asphalt,due to its crystalline existence of ultimate load carrying capacity and irreversible phenomenon after damage,is suitable for road sections with low traffic load and not suitable for heavy traffic use,while the three-dimensional elastic mesh structure of elastomeric high-viscosity asphalt has certain ductility and can provide certain elastic recovery at low temperatures as well as under heavy load conditions,while Elastomeric high viscous asphalt has good fatigue resistance and wider applicability than resin high viscous asphalt.Meanwhile,the grey correlation analysis of rutting dynamic stability of asphalt mixture shows that the softening point and creep recovery rate R of high viscous asphalt have good correlation with the rutting dynamic stability of high viscous asphalt mixture,which can be used for high temperature road performance evaluation.