Influence of the aggregate skeleton matrix and volumetric composition on the resistance of stone mastic asphalt to permanent deformation

Abstract

The influence of different aggregate skeleton matrices, as well volumetric composition and mixture stiffness, on the resistance of SMA to permanent deformation was assessed. Nine SMA withdifferent optimised aggregate skeleton matrices, studied elsewhere, were now evaluated to permanent deformation with wheel tracking. The results were statistically analysed concerning relationship withspecimens’ volumetric characteristics, Marshall properties and mixture stiffness. Aggregate skeleton optimised with the dry rodded compaction tend to produce asphalt mixtures similar to SMA designedwith pre established grading envelopes. SMA with aggregate skeleton optimised with Proctor and steel roller compaction showed higher coarse aggregates and binder contents, and thus, it is expected abetter cracking resistance and durability for the same level of resistance to permanent deformation. Statistical analysis shows that the new proposed property (ratio between binder film thickness andporosity) and, ratio between Marshall stability and flow had the best correlations with permanent deformation properties.