Comparative study of asphalt concrete laboratory compaction methods to simulate field compaction

The main objective of this study was to compare different laboratory compaction methods to field compaction and to select the laboratory method that was similar or close in compaction to that of the field. The candidate compaction methods were: (a) Marshall Automatic Impact Compaction; (b) Marshall Manual Impact Compaction; (c) California Kneading Compaction; (d) Gyratory Shear Compaction (angle of gyration 1.25°); and (e) Gyratory Shear Compaction (angle of gyration 6°). The evaluation of the five laboratory compaction methods was based on the similarity between the engineering properties of the laboratory compacted samples and the field cores. The engineering properties studied were resilient modulus, air voids, bulk density, and static creep behavior. The laboratory compacted specimens and field cores were also evaluated with the objective of identifying a promising laboratory compaction technique which would be able to produce mixtures with engineering properties closest to those of mixtures compacted in the field. Samples for this study were selected from four projects located at different locations in the Eastern Province of Saudi Arabia. The principal conclusion of the study was that the Gyratory Shear Compaction (angle of gyration 1.25°) method best represented the engineering properties of the field cores.