Dependence of Volumetric Parameters of Hot Mix Asphalts on Testing Methods

Assessing the volumetrics of hot mix asphalts (HMAs) is an important aspect of quality control and quality assurance (QC/QA) procedures. The economic value of HMAs is usually assessed in terms of their mix bulk specific gravity (Gmb), air void content (AV), voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). However, the results for specific gravity can vary with the coring process and method used in the experimental measurements. In light of these concerns, this study focused on the assessment of the dependence of the measured volumetrics of HMA wearing courses on the testing and coring procedures. A wide range of methods for the measurement of specific gravities and surface texture was considered. Analyses showed that the coring process, measurement methodology, and core diameter can all substantially affect the results of HMA volumetrics measurements; the effects of the selection of the testing technique are not negligible and can be critical. At the same time, results demonstrate that there is potential for reducing the cost and duration of massive coring processes, as well as other negative impacts (e.g. road surface defects and environmental diseconomies).