Evaluation of Notched-Wedge Longitudinal Joint Construction

The proper construction of longitudinal joints is critical to the overall performance of a hot-mix asphalt (HMA) pavement. Many times the in-place density at and across the longitudinal joint is substantially lower than the density of the remainder of the HMA surface. This low in-place density increases the potential for cracking and raveling to develop along the joint. Research has shown that the use of the notched-wedge joint has the potential to increase the density at the longitudinal joint, which should result in a longer-lasting pavement. The notched-wedge joint construction technique was compared with conventional longitudinal joint construction techniques on projects in five states (Colorado, Indiana, Alabama, Wisconsin, and Maryland). The evaluation consisted of comparing the in-place densities obtained through pavement cores at five locations across the longitudinal joint of the pavement: at the centerline and at 150 mm (6 in.) and 450 mm (18 in.) on either side of the centerline. The results of the study indicate that the notched-wedge joint can be successfully used to increase the in-place density at the longitudinal joint. Some decrease in the in-place density was observed at the 150-mm (6-in.) location in the second lane (hot side) when the notched-wedge joint was used.