Effectiveness of Dominant Aggregate Size Range-Interstitial Component (DASR-IC) criteria for evaluate rutting performance of brazilian asphalt mixtures

Abstract

Traditionally, asphalt mixtures design methods do not explicitly consider the role of aggregates in field performance. A typical distress of early ages in asphalt layers is permanent deformation, which is remarkably influenced by the characteristics of the aggregates, especially gradation. This work is focused on an approach to evaluation and gradation selection that aims to help the composition of a mineral skeleton with proper interlocking and stability to resist to rutting, called DASR - IC model [denoted in Brazil as Faixa de Agregados Dominantes (FAD)]. The aim is to verify the effectiveness of criteria proposed to 3 DASR - IC model parameters in eleven Brazilian asphalt mixtures. The Flow Number (FN) from uniaxial repeated load test expresses the resistance to permanent deformation. It was concluded that the DASR porosity, related to the coarse aggregates, can satisfactorily estimate the resistance to permanent deformation of asphalt mixtures, being the main DASR – IC model parameter. Other parameters such as Disruption Factor (DF) and Fine Aggregate Ratio (FAR) were characterized as secondary parameters that complement the analysis and take into account the fine portion. All recommended ranges (criteria) for these parameters are suitable and could lead to a rational gradation selection to reduce the susceptibility to permanent deformation in asphalt mixtures in the field.