Abstract
A significant cause of premature pavement deterioration can be attributed to the initiation and propagation of cracks. Hot-mix asphalt (HMA) is thought to be an anisotropic material in which the sample orientation with respect to compaction should be considered when laboratory tests are conducted. The sample orientation could be an important factor for fracture testing of HMA because crack paths are influenced by aggregates. Previous research on the anisotropic nature of HMA has mainly focused on bulk material properties at high temperatures. This research investigated the anisotropic effect of low temperatures for bulk material and separation properties. These two properties were analyzed for samples compacted with the Superpave® gyratory compactor and cored field samples with both vertical and horizontal orientations. Three mixtures were tested for complex modulus, creep compliance, tensile strength, and fracture energy. It was determined that orientation influenced the complex modulus and creep compliance results for these three mixtures. Statistical analysis conducted on the tensile strength test results determined that the mean values were similar. The results from the fracture energy tests did not prove consistent, as there were no clear trends between the three mixtures and the specimen fabrication method.
Get full access to this article
View all access options for this article.