3D Numerical Modeling Methods to Characterize Real Aggregate Shapes

A statistical rule of the Hurst exponent was obtained based on the 2D morphology characteristic of independent aggregate sections, which were processed into binary images by image processing technologies. Meanwhile, a random contour of one aggregate section can be created by the improved fractional Brownian movement (FBM). This contour, which is perpendicular to the construction axis, is regarded as the connecting surface between the upper and lower surfaces of an aggregate waiting for construction. The upper and lower surfaces, which are respectively generated based on the improved random midpoint displacement method, are assembled into a complete numerical model of the 3D aggregate. Based on the same lengthwise ratio, the constructed numerical aggregates have the similar contours, flakiness ratios and sphericities with those of the real aggregates. The volume distribution law of random numerical aggregates has a resemblance to that of measured real aggregates. The constructed numerical aggregates based on aggregate gradations of a test were placed into a cylindrical asphalt concrete specimen. Under the same working condition, the simulation result is in agreement with data of the uniaxial compression creep test.