Gradation-based framework for asphalt mixture

Aggregates are the major component of asphalt mixtures, greatly influencing the mixtures resistance to failure. The structure that is formed by the aggregates will depend mostly on the size distribution, shape and mineral composition. Coarse aggregate have a strong influence on the resistance to rutting, while fines provide stability to the mixture. In the present study a generalized framework is developed to identify the range of aggregate sizes which form the load carrying structure in hot mix asphalt and determine its quality. The method has been developed as a numerical procedure based on packing theory. Parameters like porosity and coordination number have been used to evaluate the quality of the load carrying structure and relate it to resistance to rutting. The framework has been evaluated on several field and laboratory mixtures and related to their rutting performance. The gradation analysis of the mixtures has compared favorably with the performances reported from the field and laboratory testing. The developed gradation analysis framework has proven to be a tool to identify those mixtures with a poor rutting performance based on the gradation of the aggregates.