Asphalt mortar design method and its rationality verification in cross-scale prediction

The development of asphalt mortar design methods is a prerequisite for cross-scale prediction from asphalt mortar scale to asphalt concrete scale. Existing studies have given some asphalt mortar design methods. However, these studies have not explored the impact of different maximum aggregate sizes of asphalt mortar on the cross-scale prediction results, nor have they judged the rationality of mortar design methods. In order to find the appropriate maximum particle size of asphalt mortar and develop an asphalt mortar design method that is suitable for predicting the mechanical behaviour of asphalt concrete, in this study, two commonly used particle sizes (2.36 and 1.18 mm) were selected as the maximum aggregate size of asphalt mortar, and an asphalt mortar design method, including the assumption of boundary particle size, was proposed. Then, utilising cross-scale simulation, the maximum aggregate size of asphalt mortar was compared and selected, and the rationality of the proposed asphalt mortar design method was verified. The results indicate that asphalt mortar with a maximum aggregate size of 1.18 mm is more suitable for predicting the mechanical behaviour of AC-13C, AC-20C, and AC-25C asphalt concrete. The design method of asphalt mortar containing the assumption of boundary particle size is reasonable.