A new laboratory method to characterize gradation segregation of large stone asphalt mixtures

By simulating gradation segregation of large stone asphalt mixtures during production, transportation and construction, a new test machine and laboratory method to characterize gradation segregation of large stone asphalt mixtures are developed, and a new index—Δ∑Pi is brought forward to evaluate gradation segregation of large stone asphalt mixtures. According to investigation results, homogeneity of large stone asphalt mixtures is the best for Bailey Method, medium for Coarse Aggregate Voids Filling Method and the worst for Superpave Method. For the same kind of design method, the homogeneity of large stone asphalt mixtures becomes worse with the increase of nominal maximum aggregate size.