Application Study Of RAP Cold Regeneration Technology In Micrometer

With the rapid development of social economy,the aggravation of highway traffic has led to the gradual seriousness of road surface damage,and then the highway has entered a large-scale maintenance period,and has been widely used because of the excellent characteristics of rapid,economical and efficient preventive maintenance technology at microsurface.In order to respond well to the development model of green maintenance and low-carbon maintenance and promote resource recycling,the recycling rate of old asphalt pavement materials(Re‐cycled Asphalt Pavement,RAP)of national highway maintenance,national and provincial trunk highways and expressways is required to reach 40%,70%,100%.Therefore,the recycling of RAP has become an important research direction in the road maintenance industry.Relying on the research project of key technologies and equipment application research of low-carbon and efficient recycling of road solid waste materials in Ordos Lutai New Materials Group Co Ltd Inner Mongolia,on the basis of summarizing and analyzing the current status of RAP use and research progress,the road performance and mixture tests of different dosages of RAP under different particle sizes were carried out,and RAP was verified through research and comparative analysis.The feasibility of applying the technology at the microsurface and the practicality of the road performance,and through the data fitting analysis between the microsurface and the mixture,the test standard range of the microsurface mixture under different RAP particle sizes was proposed for the first time,and the main research contents and results are as follows.Firstly,the RAP is screened,separated and extracted,and various index tests are carried out to determine the recovered asphalt content,penetration degree and other index values,so as to provide a basis for the subsequent mixing of new and old mixtures.The results show that the 25°C penetration and 15°C ductility of recycled asphalt are significantly reduced,while the softening point increases,and the old bitumen has been seriously aged,but its bitumen index still meets the standard.The overall pass rate of the RAP aggregate with a particle size of 0-5mm is increased after extraction,and after stripping,the false particle rate is greatly reduced,and the asphalt content in the particle size of 0-3mm RAP is higher than that of 0-5mm RAP.Through the microsurface experimental study of 30%,40% and 50% of the two different particle sizes of RAP 0-3mm and 0-5mm,RAP was passed Then,the wear resistance,rutting resistance,stability and early strength of RAP on cold recycled microsurface were analyzed by wet wheel wear test,load wheel sticking sand test,stability test,cohesion test and rut deformation test.Secondly,the changes of high and low temperature performance and water loss resistance were studied by high temperature rutting test,low temperature bending test,Marshall stability test and freeze-thaw splitting test.The test results show that the increase of RAP content has an adverse effect on the road performance of the mixture at the microsurface,and the performance of the mixture at the cold recycled microsurface with a particle size of 0-5mm is better than that at the cold recycled microsurface mixture with a particle size of 0-3mm RAP.Through the analysis and comparison of the above road performance test results,it is found that in the range of RAP particle size below 5mm,with the larger the particle size,the road performance is better,and the RAP content is less than 50%.The road performance shows a downward trend with the increase of the dosage,and the overall performance of the mixture at the microsurface of RAP recycled material with a particle size of 0-5mm is better,and it can continue to be incorporated in a large proportion to improve the solid waste utilization rate of R AP recycler.For the wet wheel wear value of the mixture at the microsurface,the RAP content with a particle size of 0-3mm reaches the standard maximum value at 74%,and the RAP content with a particle size of 0-5mm reaches the standard maximum value at 60.6%.For the deformation rate of the mixture rut width at the microsurface,the RAP content with a particle size of 0-3mm reaches the normative maximum at 76%,and the particle size is The0-5mm RAP content reaches the normative maximum at 92%.For the 6d wet wheel wear value of the mixture immersed in water at the microsurface,the RAP content with a particle size of 0-3mm reaches the normative maximum value at 56%,and the particle size is 0-5mm The RAP dosage reaches the normative maximum at 63%.