Influence of field compaction pattern on asphalt pavement uniformity Conference Paper uri icon


  • Field compaction of asphalt mixtures is an important process that influences performance of asphalt pavements. This study evaluates the relationship between different field compaction patterns and the uniformity of air void distribution in asphalt pavements. A number of projects with different hot mix asphalt (HMA) types were compacted, and cores were taken at different locations from these projects. The X-ray Computed Tomography (X-ray CT) system was used to capture the air void distributions in these cores. The images were used to develop maps of air void distributions across the pavement surface and depth that were useful to study the uniformity of air void distributions. These distributions were further quantified by computing a uniformity index and the differences in percent air voids across the depth. The analysis results have revealed that the uniformity of air void distribution is highly related to the compaction pattern and the sequence of using different compaction equipment. More importantly, the efficiency of compaction (reducing air voids) at a point was found to be a function of the location of this point with respect to the roller compactor width. The results in this paper have supported the development of the "compaction index (CI)," which quantifies the degree of field compaction. The CI is a function of number of passes at a point and the position of the point with respect to the compaction roller width. This index was found to correlate reasonably well with percent air voids in the pavement. Pavements that were compacted to have more uniform CI also had more uniform air void distribution. The CI calculated from field compaction had good relationship with the slope of the compaction curve obtained from the Superpave gyratory compactor. This relationship offers the opportunity to predict field compactability based on laboratory measurements. The compaction of longitudinal joints was investigated and recommendations were put forward to improve joint compaction.

published proceedings

  • Asphalt Paving Technology: Association of Asphalt Paving Technologists-Proceedings of the Technical Sessions

author list (cited authors)

  • Kassem, E., Masad, E., Chowdhury, A., & Claros, G.

complete list of authors

  • Kassem, E||Masad, E||Chowdhury, A||Claros, G

publication date

  • December 2008