Adaptive construction approach for virtual samples of hot mix asphalt based on 3-D structural characterization of laboratory compact specimens

Marshall and Superpave gyratory compactor (SGC) methods are widely applied in pavement engineering. Laboratory samples derived from the two methods have great difference in aggregate structure, which should be adequately characterized and considered to generate virtual samples of Marshall and Superpave mixture. To characterize the aggregate structure in realistic samples of asphalt mixture, six laboratory-compacted samples, three Marshall and three SGC, are prepared under SMA-13 gradation and then three-dimensionally (3-D) reconstructed. Next, the statistical indicators of the aggregate structure are extracted, analyzed, and characterized to develop an algorithm for adaptive construction of virtual samples conforming to the structural characteristics of realistic samples. Four virtual samples, two Marshall and two SGC, are generated to verify the control effect of the proposed approach on the aggregate structure to simulate the internal structure of realistic samples. Results indicate that virtual samples capture close structural characteristics with laboratory samples of Marshall and SGC, which validates the effectiveness of the proposed approach.