Laboratory and Field Study on Compaction Quality of an Asphalt Pavement.

Compaction of hot mix asphalt (HMA) layer is a process of densification through the application of vibratory, dead weight and/or pneumatic tires compactors. These processes are employed independently or in combination, depending on factors such as type of asphalt mix, layer thickness, and weather conditions, to achieve desired density of HMA pavement layers. Appropriate compaction (desired density) of the asphalt mixture is one of the important factors that influence long term performance of an asphalt pavement. During the compaction of HMA layer using vibratory rollers, the applied load and vibration energy cause reorientation and interlocking of asphalt coated aggregates resulting in increase in density. Good compaction is necessary for achieving target specifications such as required density of asphalt layers, stiffness, or volumetric properties of the asphalt mix. These specifications are designed to maximize the resistance of the pavement to deformation, cracking, raveling, moisture damage, and rutting. In the United States of America, target specifications for quality control and assurance of asphalt pavements are usually given in terms of the density of roadway cores extracted from the completed pavement. This paper investigates the level of compaction (in terms of density), that is achievable both in the laboratory and in the field. Compaction quality as a function of compaction time/roller passes and pavement thickness is studied. In addition, the uniformity of compaction over the entire length of the pavement, and the variation in density laterally across the pavement are examined during pavement construction in the field. The results of this study provide insight into the compaction quality that can be achieved during construction. Such information would is helpful for a successful design and the implementation of emerging technologies such as Intelligent Compaction. [ABSTRACT FROM AUTHOR]