Conventionally cracks in asphalt pavements are repaired by milling the pavement around the crack and placing and compacting new Hot Mix Asphalt (HMA) material. Unfortunately, after a period of time, this often results in two new joints and the crack reflecting through the repair. This may lead to problems such as pavement surface deterioration and moisture moving into the pavement structure. An innovative crack repair method has been developed that includes heating the area surrounding the crack using an infrared system and removing the material immediately adjacent to the crack. A fine asphalt mix that is rich in asphalt cement is then used to fill the area where material has been removed from. The area is overfilled and then finally compacted, leaving a patch that is well bonded to material below and adjacent and flush with the remainder of the pavement. Initially infrared technology was used successfully in hot in-place recycling and longitudinal joint construction and has now also been applied to crack repairs with success. The Region of Waterloo and the City of Cambridge have used the infrared crack repair method on both binder and surface course layers. Using infrared technology, it was possible to repair significant cracks and provide a quality pavement. Examples of these projects are included in this paper. The effectiveness of using this technology has been evaluated and monitored through surface smoothness evaluations, density measurements and extracting core samples. The results and findings from these tests are presented in the paper. The results of the density testing indicated that adequate compaction was easily achieved throughout the projects. Cores showed that the new material was well bond to the existing pavement. Details of this maintenance process and the associated costs in comparison to using conventional methods are described. Generally, the costs of the conventional and infrared methods of crack repair are comparable. Cores taken from an infrared joint repair carried out 12 years ago show that the joint between the new material and the old material is not apparent at the surface or in core samples and there were no surface distresses observed in these areas. Compared with the conventional method, very little new HMA material is required for infrared repairs. Although it is unlikely that the new method will fully replace the conventional one, it can be considered as an additional, proven tool in a pavement maintenance tool box.
