Performance of cement-stabilized macadam roads based on aggregate gradation interpolation tests.

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.