ABSTRACT
During construction, the compaction of asphalt layers is critically important to the life-cycle performance and durability of the pavement surface, particularly for aircraft pavements. As a result, there is a strong focus on achieving a high level of compaction during airport surfacing projects, with specification limits for the density of the paved construction joints (the joints), as well as the area of contiguously paved surface between the paving joints (the mat). In recognition of the greater difficulty in achieving high density at the joints, there is usually a relaxed requirement for joint density, compared to the mat. Furthermore, there is usually different treatments of the joints depending on their temperature at the time the adjacent paving lane is performed, with ‘hot’, ‘warm’ and ‘cold’ joint categories commonly defined. To allow ‘warm’ joints to be treated as ‘hot’ joints during construction, joint heaters are often used to reheat the asphalt along the joint, immediately prior to the adjacent lane of asphalt being paved. Although there are different forms of reheating equipment, infrared gas burners are most common and avoid the direct application of a naked flame to the asphalt mixture or surface. This research quantified the benefit of a typical asphalt paving joint heater for better joint density and finish, during a runway resurfacing project. The temperature of the joints and the mat was monitored over seven days, three of which used the joint heater and four of which did not. Furthermore, the density of the joints and mat were compared, and the effect of the prevailing weather conditions was considered. It was clear that the joint heater significantly increased the joint temperature and significantly improved the joint density and finish. Recommendations include mandating the use of joint heaters for runway resurfacing and the potential to remove ‘warm’ joints from specifications, meaning all joints would be considered to be ‘cold’ or would be reheated to ensure they are ‘hot’.
