HOT MIX ASPHALT LONGITUDINAL JOINT DETERIORATION
Abstract
The notched wedge joint design has proven to be the preferred method of joint
construction by research studies given the obvious benefits of higher density, reduced
permeability and greater edge confinement when compared to traditional joint methods.
Greater quality of joints and improved pavement performance is evident in states that specify
the joint type, but not without careful quality control during the construction process.
Pavements exhibit longitudinal joint cracking as early as three years into the service life of a
roadway, exposing the pavement to damage and costly repairs, or total replacement.
Workmanship determines the quality of the finished joint and good construction is the only
means to reduce permeability caused by low densities. The notched wedge joint design
seems to ensure higher densities and less potential for failure.
Prior to this study, contractor input was rarely solicited by the Wisconsin Department
of Transportation (WisDOT) or by the industry as a whole. State roadway projects were
chosen based on DOT collected information, and contractor representatives were surveyed to
gain a greater understanding of the contractor perspective and process. The survey results
exhibited many commonalities in method as well as differences in opinions and unique
practices supported by industry research. This information was analyzed and used to
propose specification revisions and to develop recommendations for a joint density testing
process for performance data collection.