This study adopted the uniform interpolation method to obtain five gradation types (labeled A, B, C, D, and E, from "coarse-grained" to "fine-grained" types) based on the skeleton dense structure and cement-stabilized macadam (CSM) aggregate gradation range recommended by current specifications. The optimum water content of the CSM exhibited a linear increase with gradation, whereas the maximum dry density exhibited a variation that can be described by a quadratic curve, for which the peak maximum dry density was near the maximum dry density of the Type B gradation. In the CSM structure, the skeleton void effect of the coarse-grained aggregate, the filling effect of the fine-grained aggregate, and the cementation effect of the cement and aggregate exhibited corresponding fluctuations. The ability to resist temperature shrinkage deformation was reduced. Additionally, the optimum values of the compressive strength and compression rebound modulus of the CSM plotted near the curve of the Type D gradation.
Keywords: CSM; aggregate gradation; experimental study; road performance; skeleton dense structure; uniform interpolation.