Study On The Influence Of Asphalt Chemical Composition On The Performance Of Pervious Asphalt Pavement

The extensive promotion of permeable asphalt pavement has led to the rapid development of high-viscosity modified asphalt,but the developed high-viscosity modified asphalt still has the defect of unstable viscosity.High-viscosity modified asphalt also needs to improve asphalt-aggregate adhesion,asphalt viscosity and aging resistance during use.In order to configure the asphalt with better performance so that it can better serve the traffic demand,it is necessary to establish the relationship between the characteristic functional groups of the asphalt and the properties of the asphalt.The Fourier infrared spectrometer was used to test and calculate the functional group index of each functional group in 12 kinds of asphalt.The Gv OC theoretical system was used to calculate the adhesion binding energy and asphalt cohesive binding energy of asphalt and aggregate.The dynamic viscosity of asphalt at 60℃is measured using a cloth-type rotary viscometer at 135℃and 175℃.The gray correlation system and multivariate linear programming were used to analyze the relationship between the characteristic functional groups of asphalt and the properties of asphalt,and the relationship between the characteristic functional groups of asphalt and the asphalt mixture’s resistance to water damage and high temperature rutting resistance was also explored.The following conclusions are drawn:Asphalt characteristic functional groups that have a greater influence on asphalt performance are:methylbenzene,hydrogen group on benzene ring,methylene,the C–H bond of methylene,vinyl,styrene,butadiene,C-O,methylene base.When the content of methylbenzene increases,the adhesion of matrix asphalt-aggregate and SBS modified asphalt-aggregate will increase.The improvement of asphalt-aggregate adhesion will improve the ability of asphalt pavement to resist cracking at the asphalt-aggregate interface.High-viscosity modified asphalt-aggregate adhesion decreases;when the hydrogen group content on the methylbenzene increases,the adhesion of the matrix asphalt-aggregate,high viscosity modified asphalt-aggregate,SBS modified asphalt-aggregate decreases;when the methylbenzene content increases,the adhesion of the high viscosity modified asphalt-aggregate,matrix asphalt-aggregate decreases,and SBS modified asphalt-aggregate adhesion improves;when the=CH-bond of methylene increases,the viscosity and toughness of the base asphalt,SBS modified asphalt,and high-viscosity modified asphalt all decrease.Decreased viscosity will reduce the ability of asphalt pavement to resist cracking at the asphalt-asphalt interface;when the vinyl content increases,the high viscosity modified asphalt’s 60℃dynamic viscosity,the high viscosity modified asphalt’s 175℃rotational viscosity and SBS modified asphalt’s 60℃dynamic viscosity will decrease,reducing asphalt 60℃dynamic viscosity will reduce the anti-rutting ability of asphalt pavement at high temperature,and the base asphalt’s 175℃rotational viscosity will increase;when the styrene content increases,the base asphalt’s 60℃dynamic viscosity will increase.Viscosity modified asphalt’s 60℃dynamic viscosity and the 135℃rotational viscosity of matrix asphalt and SBS modified asphalt are reduced,while the 175℃rotational viscosity of matrix asphalt,the 175℃rotational viscosity of SBS modified asphalt and the 175℃rotational viscosity of high viscosity modified asphalt are reduced;when the content of butadiene increases,The 135℃rotational viscosity of base asphalt and the 135℃rotational viscosity of SBS modified asphalt decreased,the high viscosity modified asphalt’s 135℃rotational viscosity increased,and the 175℃rotating viscosity of base asphalt,the 175℃rotating viscosity of SBS modified asphalt and the 175℃rotating viscosity of high viscosity modified asphalt decreased.Using multiple linear regression analysis,the relationship model between asphalt characteristic functional groups and asphalt-aggregate adhesion binding energy and the relationship model with asphalt cohesive binding energy.Both models have 70%accuracy.The short-term aging of asphalt has a positive effect on various properties of asphalt.Different asphalt functional groups have different effects on the short-term aging of asphalt.After short-term aging of asphalt,the content of methylene decreases,and the content of the remaining functional groups of asphalt increases.Before and after short-term aging of the asphalt,when the C-O content increases by 0.01,the adhesion of the high-viscosity modified asphalt 1-aggregate is improved.14.91ergs/cm~2,70#matrix asphalt-aggregate has the least decrease in adhesion,3.27ergs/cm~2,and SBS modified asphalt 2-aggregate has the most decrease in adhesion,7.04ergs/cm~2.When the methylene content increases by 0.01,the viscosity of 70#matrix increases the most,which is 24.95 ergs/cm~2,and the viscosity of the high-viscosity modified asphalt 1 increases the least,which is 7.04ergs/cm~2.The residual stability and dynamic stability of the asphalt mixture in water will increase with the increase of the content of methylbenzene,hydrogen groups on the benzene ring,vinyl group and benzene ring.The resistance to water damage and high temperature rutting of asphalt pavement under the action of vinyl is the fastest improvement,and the resistance to water damage and high temperature rutting of asphalt pavement under the action of methylbenzene is the slowest.