Research On Road Performance Of SBR Modified Asphalt Mixtures With In-situ Thermal Regeneration

At present,our country adheres to the path of sustainable development.For the transportation industry,saving resources and protecting the environment are inevitable development directions.Asphalt pavement hot-in-place recycling technology is an environment-friendly pavement repair method,which has good economic and social benefits,and has been vigorously promoted and applied in our country.Years of practice has proved that after road maintenance is repaired with in-situ thermal regeneration technology,the pavement can ensure good road performance,reduce waste of resources and save a lot of costs.At present,researches on recycled asphalt mixtures are mainly focused on ordinary asphalt mixtures and SBS modified asphalt mixtures,while SBR modified asphalt mixtures are rarely involved.Therefore,this article mainly studies the hot-in-place regeneration technology of SBR modified asphalt mixture,explores the road performance of hot-in-place regeneration SBR modified asphalt mixture,and provides technology for the future application of hot-in-place regeneration SBR modified asphalt mixture.reference.The main work and research results are as follows:(1)Through the measurement and analysis of the various properties of the RAP material,it is concluded that the basic properties of the RAP material can meet the technical specifications of the hot-in-place regenerated asphalt mixture.Among them,the old asphalt in the RAP material has a low degree of aging and has a good regeneration capacity;the old aggregate is more refined,and new aggregates need to be added to adjust the gradation of the recycled mixture during in-situ thermal regeneration.(2)Using the method of indoor test,the improvement effect of the mixing amount of SBR modifier on the penetration,softening point,ductility,rotational viscosity and other technical indicators of the base asphalt was studied,and the best SBR modifier was obtained.Blending amount;At the same time,the influence of shear time and shear temperature on the preparation of SBR modified asphalt was studied by using the controlled variable method,and the optimal shear temperature and optimal shear time for the preparation of SBR modified asphalt were obtained.(3)Using the performance design method,the regeneration effect of type A regenerant(Shengquan brand)and type B regenerant(shuangcheng brand)on the aging asphalt in RAP materials was compared and the respective optimal dosages were obtained.;At the same time,by comparing the regeneration effect of the two regenerators on the old asphalt in the RAP material at the same content,it is concluded that the A type regenerator has a better regeneration effect,and it is decided to apply it to the in-situ thermal regeneration of the SBR modified asphalt mixture.Research on road performance.(4)The Marshall test method was used to design the mix ratio of the in-situ thermal regeneration SBR modified asphalt mixture and the ordinary asphalt mixture,and the respective best oil-stone ratios were determined;at the same time,the high temperature stability and low temperature crack resistance of the two asphalt mixtures,Comparative study of water stability.The study shows that the high temperature stability and low temperature crack resistance of the in-situ thermally recycled SBR modified asphalt mixture are better than that of the ordinary asphalt mixture,and the water stability is not much different.This shows that the hot-in-place regeneration SBR modified asphalt mixture has good road performance and can meet the requirements of relevant technical specifications.