Research On RAP Variability And Recycled Mixture Road Performance Result

Based on the asphalt pavement maintenance engineering as the researchbackground, take a highway of Chong qing as the research object, according to thestandard highway engineering asphalt and asphalt mixture test procedures (JTGE20-2011), according to take different sources, different use year, different pavementstructure layer, different recycle technology, different curing condition of the old asphaltmixture sample, to take samples for the penetration, softening point, ductility, asphaltcontent, gradation test. The mean, variance coefficient as the evaluation index toevaluation the RAP, to make analysis and evaluation or comparison the variability of theproperties in asphalt mixing material.Researching found that different sources, different use year, different pavementstructure layer, different technology, different curing condition of the old asphaltmixture, asphalt, asphalt content and the gradation have the variability. Among them,different sources, different use year, different pavement structure layer, different curingcondition of the old asphalt in properties, asphalt content and gradation variability islarger and the different recovery process of old material mineral aggregate gradationvariability is larger, asphalt, asphalt content variability is small, the effect of recoveryprocess on gradation is larger, less influence on the properties of asphalt and asphaltcontent.Based on RAP has variability, to analyse the variability in the RAP of the recycledmixture to asphalt road，effect, found that the effect of asphalt is the first, second is theasphalt content, the third is the aggregate gradation. Therefore, propose the variabilityof the cluster analysis method to reduce the asphalt properties and asphalt content, aswell as proposed reference material method and ensure the recovery process, thecrushing process recycling material close to the original pavement gradation. Reducethe variability of the material properties of the old asphalt mixture effectively.At the same time, to analyse the variability in recycled mixture of processing, toanalyse the road performance of direct regeneration and after regeneration, prove thatthe variability of reference material synthesis method can effectively control the RAP on the road performance of asphalt mixture influence, guarantee the performance stabilityof the recycled mixture, while improve the road performance of asphalt mixture.