Abstract:
To study the homogeneity of reclaimed asphalt pavement material(RAP),the basic aggregate indicators of RAP material were first tested according to the requirements of the highway base layer.Then, the gradation variability and agglomeration status of RAP material were analyzed using screening and extraction tests.The grey correlation method was used to analyze the correlation between RAP material availability, overall agglomeration rate, and gradation.The research results indicate that RAP material has less needle like particle content and higher crushing value than natural aggregate.Using 9.5 mm as the critical point, RAP grade ratios above 9.5 mm have low variability in gradation ratios below 9.5 mm, with 9.5~16 mm aggregate having the most stable sieve residue quality.The pass rate of 37.5 mm sieve has the strongest impact on the overall utilization rate of RAP material, with a correlation coefficient of 0.846.The average agglomeration rate of RAP materials is 6.4%,and the coefficient of variation of agglomeration rate of RAP materials with different particle sizes reaches 46.4%.Among them, RAP materials with particle sizes of 4.75 mm to 9.5 mm, 19 mm, and 37.5 mm have more concentrated agglomeration.The highest correlation between the percentage change of screening residue residual percentage of RAP at 19 mm and the overall agglomeration rate is 0.942.