Premature longitudinal joint failures due to low density, water intrusion, cracking, and ravelling is a common and significant issue in asphalt roadways. Joints often fail first despite the rest of the mat being constructed properly with suitable mixes. Premature joint deterioration reduces the pavement's life cycle and requires increased maintenance, wastes time, budget, environmental and safety concerns due to traffic accommodation.
In 2021 and 2022, the city conducted pilot studies using infrared heaters during paving to create heated joints. The city is continuing its study through 2023. To facilitate implementation of the joint density specification and to evaluate the overall effectiveness, the contractor was required to heat the construction joint using an infrared joint heater supplied by Heat Design Equipment in 2021. Preliminary results were encouraging with improved densities and reduction in air voids. As such, the City decided to proceed with the joint density specification on contracts in 2022/2023.
This paper presents the preliminary results of the longitudinal heated joints from the City's 3-year study, including the development of specifications, best construction practices, challenges, and maintenance. The city plans to continue heating joints, particularly on high-volume roadways and multi-lane pavements, and further improve the current specifications.