Study On Performance Of Regenerated SBS Modified Asphalt And Engineering Performance

SBS Modifier in SBS modified asphalt has been extensively applied to high-grade asphalt pavement as it improves the engineering performance of asphalt since the application of asphalt to road construction in China in the 1990 s.Because the pavement service period of asphalt is short,a large amount of aged SBS modified asphalt is produced each year,which will not only cause a huge environmental pressure,but also will aggravate the non-renewable energy crisis.If the aged SBS modified asphalt can be applied to road construction once again by adopting regeneration technique,which can not only solve the environmental issues,but also practice the idea of sustainable development,making it meet the needs of engineering performance.The main contents of this paper are as follows:Firstly,SBS modified asphalt was aged by three experiments.First of all,the SBS modified asphalt was aged for 85 minutes using a Rotating Film Oven(RTFO)to obtain the preliminary aging material so as to simulate its the short-term aging under natural conditions.Then,put the preliminary aging material into the pressure aging instrument for 20 hours to obtain the required aging test material so as to simulate its long-term aging under natural conditions.Thirdly,regenerated SBS modified asphalt was obtained by adding different doses of a regenerant to the aged SBS modified asphalt material which was prepared before.Moreover,we can know the optimal amount of regenerant was 9% by comparing and analyzing the properties after regeneration.In the end,comparisons and analysis were made about the characteristics of three types of materials: unsaturated SBS modified asphalt,aged SBS modified asphalt,and regenerated SBS modified asphalt.Next,this paper will study the engineering properties of the regenerated SBS modified asphalt mixture by comparing with the engineering performance of the original SBS modified asphalt mixture,the aged SBS modified asphalt mixture and the regenerated SBS modified asphalt mixture.According to the grading calculation and relevant specifications,we select the AC-13 aggregate grading and adopt the Marshall standard experiment to determine the optimum bitumen-aggregate ratio of three types of SBS modified asphalt mixture,knowing that the optimum bitumen-aggregate ratio of the original SBS modified asphalt mixture is 4.35% and the ratio of the regenerated SBS modified asphalt mixture is 4.45%.The Marshall specimen and related test blocks will be made based on the above results.In addition,three types of mixed specimens were subjected to comparative study on the engineering properties such as high temperature stability,low temperature stability,water stability,and fatigue performance.We can find that the engineering properties of the SBS modified asphalt mixture decrease seriously after aging and the engineering properties of regenerated SBS modified improve,which can meet regulatory requirements.However,there is still a certain gap when comparing them with the engineering performance of the original SBS modified asphalt mixture,indicating that the aging process of the SBS modified asphalt is irreversible and further research is required on the application prospects of the aging SBS modified asphalt.Finally,this paper will explore whether the regenerated SBS modified asphalt can meet the engineering performance requirements as the main purpose after regeneration is engineering application.In this paper,road performance tests were done by selecting A-C13 gradation,determining the optimum bitumen-aggregate ratio of three types of mixture(original SBS modified asphalt,aged SBS modified asphalt,regenerated SBS modified asphalt)and making Marshall specimens.The engineering properties mainly explore the high temperature stability,low temperature crack resistance,water stability,fatigue properties of regenerated SBS modified asphalt.The engineering properties mainly explore the high temperature stability,low temperature crack resistance,water stability,fatigue properties of regenerated SBS modified asphalt.In this paper,we explore regenerated SBS modified asphalt’s high temperature stability through high temperature rutting test and analyzing its low temperature crack resistance through the Marshall test and freeze-thaw splitting test as well as discussing its water stability through flooding Marshall and conducting experimental analysis by choosing control stress and strain to explore the fatigue performance.At the same time,the application prospects of regenerated SBS modified asphalt are inferred by comparing and analyzing the engineering performance of three kinds of asphalt.We can find that the properties of aged SBS modified asphalt after regeneration are improved both in terms of performance and road performance,and can meet the specifications.But there is still a certain gap when comparing them with the original SBS modified asphalt,which manifest that the aging process of SBS modified asphalt is irreversible and the application prospect of the regenerated SBS modified asphalt needs further study.