Study On Materials And Structures Of Recycled Asphalt Mixture Pavement

As a special asphalt mixture, the material properties and the performance in the actual pavement structure are important research directions of recycled asphalt mixture. Aimed to study this problem, in this paper, a comparative study of deformation properties and water stable performance in laboratory between new AC-25 and recycled AC-25; Get the fatigue laws of the two different asphalt mixtures under different conditions through lab experiments,theoretical analysis and model calculations in pavement structure;Through calculating the degree of fatigue damage at different temperatures and axle load, fatigue life of pavement is been analyzed. The following are the main conclusions:1)Water stable performance and deformation properties of the two mixes are analyzed by laboratory test, and the result is that the recycled mixes’ deformation properties is better than the new mixes, the two mixes are both able to meet regulatory requirements;The two mixes’ water stable performance are both able to meet regulatory requirement,but different test method will resulit different results.2)Distribution studies of pavement temperature and axle load in Zhengzhou were completed. Distribution of temperature shows that the distribution of pavement temperature in Zhengzhou mainly between 8~23℃, the temperature above 38℃ or below 2.5℃ is quite few. Axle load range was divided to 10 parties in every 2t and found that the interval of 2-14 t takes up about 90% of the axle load distribution.3)Indirect tensile fatigue test was done to both the two mixes and found the new’s property to Resistant fatigue failure is better than recycled’s, but the recycled’s sensitivity to stress is lower. The transverse tensile strain were calculated to get the strain fatigue equation without the influence of tempreture of new and recycled mixture,the atigue equation are80.10022.0-N= ε,88.10009.0-N= ε.4)ANSYS model of pavement structure was established to calculate the maximum tensile strain of bottom of surface layer. Under the same axle load rating, the maximum tensile strain increases with the increasing of tempreture; Under the same temperature rating, the maximum tensile strain increases with the increasing of load.5)The strain fatigue equation of two mixes were correctd and combined with the theory of cumulative fatigue damage, then the fatigue life of the new and recycled mixes wereget, they are 13.12 years and 11.52 years.