Longitudinal joints are the long seams between paving lanes made by subsequent passes of the paver to cover the surface being paved. Longitudinal joints are often the weakest area of asphalt pavements and are susceptible to early deterioration. Deterioration starts when air, water, and contaminants find their way into the joint through areas of segregation, poor density, or inadequate bond between the two mats forming the joint. Addressing this weakness will greatly delay maintenance and increase overall pavement life.
One option to prevent longitudinal joint deterioration is to eliminate the joints altogether through echelon paving, which involves paving multiple lanes side-by-side at the same time with multiple pavers. Unfortunately, on most paving projects, the paving width is limited, and there is a need to maintain an acceptable level of traffic flow that prevents multi-lane paving. Consequently, most paving projects must be paved one lane at a time, which requires the construction of conventional joints.
Several techniques exist for the construction of longitudinal joints, and in Canada, user agencies are exploring innovations in materials, construction methods, and specifications for improving longitudinal joint performance. As a start, a survey was conducted of Canadian agencies to gain insight into the current specifications and practices utilized in Canada in the construction of longitudinal joints.
This paper discusses the results of the survey and the specifications and practices agencies reported to be acceptable and highly effective based on field performance. The paper also discusses a literature review on research of materials such as joint sealers or void-reducing asphalt membranes and construction practices that result in lower air void contents (higher densities) at the longitudinal joints and better performance.