This investigation was performed above all to study the compactibility of dense asphaltic concrete (hab 16) of various compositions during compaction in accordance with the marshall method. Marshall stability and flow value were also measured on most of the compacted specimens. A connection between heukelom's and arand's compactibility factor was verified, which facilitated the evaluation. For all the mineral aggregates used an increased addition of bitumen led to a greater compactibility. The particle shape of the mineral coarser than four mm proved to have an influence on the compactibility. The stability tests revealed that marshall specimens with two per cent air voids and/or 85 per cent voids filled with bitumen and/or 90 per cent voids filled with filler and bitumen obtained a flow value of about four mm. This was independent of the aggregate used. A mix design procedure for stable wearing courses ought to be based on a realistic method of compaction which represents post-compaction by traffic as well as compaction by rollers in respect to the volumetric relations, the compactibility and the particle orientation of the pavement.
Samenvatting