| Hot mixed asphalt (HMA) pavements are normally constructed with multiple passes of the paver, resulting in a longitudinal joint between these passes. The density of the HMA mix at the longitudinal joint is usually lower than the density of the HMA mix throughout the regular mat away from the joint. This low in-place density area usually becomes an easy target for moisture-related damages such as stripping and raveling.; A literature review on research efforts and current specifications, and a field-testing program were developed to establish the needed knowledge base for the development and implementation of a longitudinal joint specification for the Nevada Department of Transportation (NDOT).; The field-testing program evaluated the effectiveness of the five joint geometries (natural slope, edge restraining device, cut edge with asphalt tack coat, cut edge without asphalt tack coat, and tapered joint at 3:1) and two compaction techniques (rolling from the hot side with 6&inches; overlap over the cold side and rolling from the hot side 6&inches; away from the joint) in increasing the joint density and providing improved performance.; Different density trends were observed on both sides of the joint. The tapered joint and the cut edge show a good potential of improving the joint density. Further experimentation is required to verify this conclusion. |
