Infrared Asphalt Repairs
Conventional pavement repair entails removal of distressed asphalt, replacing it with new-hot-mix asphalt, and rolling it to achieve compaction and a uniform surface. A major problem with that method is the creation of “cold” joints. The new asphalt will not meld with the in-place material and the joints must be periodically sealed to keep water out.
Infrared repair utilizes equipment that heats the in-place asphalt adjacent to the repair area to a plastic (workable) state and new hot-mix asphalt is placed. The new asphalt would be maintained at a similar temperature and consistency, so the materials readily blend. The asphalt can be raked to enhance consolidation and then compacted.
Done properly, the result is a seamless patch, but there are limitations. For older pavements (15 years old or older), the asphalt binders are probably too depleted or degraded to undergo infrared patching. In some instances, binder constituents can be replenished, but that’s not practicable if the asphalt is too brittle. Also, it may not be financially beneficial to spend a lot of money patching pavement that’s near the end of its useful life.
Infrared patching is not suitable for full-depth distress. Only the top two, to two and one-half inches of asphalt can be sufficiently heated to permit consolidation. Trying to raise the temperature of deeper material would likely overheat the surface asphalt and degrade the binder. Accordingly, full-depth distress must be full-depth patched. The topmost layer of a full-depth patch could be blended in with the infrared process.
Infrared methods have been employed as rehabilitation, in lieu of overlayment; however, it’s unlikely they achieve the same results in every circumstance. As noted above, the in-place asphalt must be in relatively good condition to withstand heating and binder replenishment won’t produce “new” asphalt.