Study On The Pavement Performance Of Hot Mixed Reclaimed Asphalt Mixture Containing Recycled Oil Based Compound Regenerant

In recent years,highway asphalt pavements have begun to enter the maintenance stage.However,due to many reasons such as technology and philosophy,road maintenance is often not paid the required attention.Many roads quickly lose their pavement structure and functions due to the loss of the best maintenance opportunity,and ultimately led to relatively high costs required for carrying out their major repairs.During the overhaul of many old asphalt roads,the waste asphalt mixture is usually treated as garbage,which not only occupies a large amount of useful land,but also causes huge pollution to the environment.Owing to the aforementioned problems,this paper uses recycled oil and fat compound regenerant developed using waste engine oil and waste edible oil,to study the key technology of high RAP-content recycled asphalt mixture.Firstly,the variability of the waste asphalt mixtures recovered from the Shihuang Expressway G1811 Cangzhou Section,Tongyan Expressway G65W Tongchuan Section and G312 Lantian Section were studied to determine the nature of the recovered asphalt,the asphalt contents and the variability of the old asphalt mixtures’gradations.Following a thorough comparison,it was found that the asphalt mixture recovered from the G312 Lantian section had the least variability,its asphalt content was higher,the uniformity of its aggregates were better,and the agglomeration effect of its old aggregates after the pumping was the smallest.Secondly,the aging asphalt recovered from the old asphalt pavement was used to verify the regeneration effect of the recycled oil compounding regenerant,by focusing on analyzing the influence of heating temperature and heating time on the diffusion efficiency of the regenerant.The research results show that the recycled oil compound regenerator has a good heat resistance and weather resistance.This proved that the effect of using recycled oil and a compound regenerant to regenerate aging asphalt,is remarkable.With the extension of the heating time,the diffusion efficiency of the compound regenerant gradually increased,and the optimal diffusion temperature was 170℃.Finally,the road performance of recycled asphalt mixtures under different RAP dosages were studied.The results show that the high-temperature performance,low-temperature performance,and water stability of the recycled asphalt mixture are good,and the maximum RAP content in the recycled asphalt mixture is 45%.However,the mixture displayed the best road performance when the RAP dosage is at 40%.Through physical engineering verification,the pavement damage status and road flatness evaluation grade were excellent after the test section was opened for one year.The pavement seepage coefficient,structural depth,and pavement anti-skid performance were all 100%,and the pavement structure was excellent.The study found that the recycled asphalt mixture produced by using recycled oil compound regenerant can directly save the cost of 117.45 yuan per ton and directly reduce the material cost by 36.4%,resulting in significant social and economic benefits.