The use of gyratory compaction to assess the workability of asphalt mixtures

Abstract

In this study, the applicability of gyratory compaction data to quantify the workability of asphalt mixtures was investigated. First, gyratory compaction data were modelled based on the approach proposed by Moutier. This model is a 4-parameter sigmoidal model that constructs a densification or compacity curve, by fitting the generated experimental data, namely compacity at each gyration. Then, workability was assessed following two approaches: firstly by considering the compaction rate, and secondly by estimating the compaction energy index. For the evaluation of the proposed methods, a selection of mixtures was investigated: 11 asphalt concrete mixtures, 6 of them containing reclaimed asphalt and 1 high-modulus asphalt concrete, as well as a porous asphalt and a stone-mastic asphalt mixture. The results show that the maximum slope of the compacity curve as well as the compaction inflection point, both parameters derived from the compaction rate, are potential indicators for the workability of asphalt mixtures.