Selling the benefits to pavement owners
By Jeff Winke
Most encyclopedias and physics books credit Sir William Herschel, the British astronomer, with the discovery of infrared radiation in 1800. He found the first solid evidence that light and infrared are the same quantity that is known today as electromagnetic radiation. It probably wouldn’t be too off base to refer to infrared as “Herschel Rays.” In this contemporary era of naming rights, why not?
The deep penetrating heat of Herschel rays (errr, infrared rays!) allows repairs to occur without the risk of separating the asphalt from the aggregate subsurface. It is said to prevent moisture damage by creating seamless transitions between new and existing asphalt. This makes infrared asphalt repairs well suited for repairing uneven asphalt surfaces that may have pooling water.
As Rose Paving, LLC, Bridgeview, Illinois described it: “Infrared repair is a great option for critical repairs that don’t need more extensive resurfacing or replacement. We recommend infrared repair for issues like potholes, pavement heaving, and uneven or rough driving surfaces.”
Rose Paving offers a simple definition of infrared asphalt repair and the repair process: “Infrared asphalt repair is the process through which existing, compromised asphalt is heated and replenished before being mixed with new asphalt and compacted.
“Here’s a step-by-step guide to the repair process:
- The area to be treated is swept free from debris and thoroughly dried out, ensuring that nothing blocks the infrared repair process from reaching the asphalt surface.
- An infrared heater is placed above the damaged asphalt area and is heated for about 5-10 minutes. This heating time may vary depending on the existing aggregate, the season, and the depth of the damage. More extensive damage takes longer to treat.
- Once heated, the area to be repaired is raked, removing loose and failed aggregate.
- A rejuvenator is added to the remaining aggregate, replenishing oils lost through age and oxidization.
- New asphalt is added and mixed, ensuring the asphalt is graded to the proper level.
- Once mixed, the area is compacted with a multi-ton vibratory roller or plate, creating a seamless patch.
With this background in mind, how can a contractor best sell infrared asphalt repair? When should infrared be used to repair damaged asphalt?
“The question really should be: When should infrared NOT be used to repair damaged asphalt,” stated R.E. Kieswetter, P.Eng., president, Heat Design Equipment Inc., Kitchener, Ontario, Canada. “Our opinion is that as long as the subgrade does not appear to be rolling, we would recommend infrared to meet most needs of pavement owners. It is important to realize that using infrared instead of cutting out the bad area reduces the CO2 emissions by some 50%, and with recent climate change disclosures, all pavement owners should look at extending the life of their pavements by hot-in-place patch repair.”
For many, infrared asphalt repair is the go-to first choice for correcting pavement damage.
“Infrared repair can be used for a variety of repair applications, but some of the more common repairs include potholes, cold seams, damage around storm drains, utility cut repairs, alligatored areas,” said Michael Blake, director of marketing, KM International, North Branch, Michigan. “It is important to note that when a base failure occurs, or is in the process of occurring, infrared can be used; however, if the base failure is not addressed directly, infrared may only be a temporary solution.”
There is agreement among the experts that infrared asphalt repair technology may not be the best solution for severe repairs.
Jeff LeClair, senior business development executive for Ray-Tech Infrared, Charlestown, New Hampshire, stated that “infrared asphalt repair is best when a repair is NOT a replacement of an entire area, roadway, parking lot or driveway due to foundational earth and water issues.”
Rose Paving cautioned, “Infrared repair is an intermediate solution to pavement failure, not a permanent one. Unfortunately, infrared repair won’t solve all of your paving woes. If there are deeper structural or base problems with your asphalt, those can’t be fixed using this method. Infrared repair can be used to prevent existing damage from worsening, but areas with serious structural issues will likely fail again within 12-24 months of repair.”
However, infrared asphalt repair does play a significant role in contractors’ pavement maintenance and repair solutions.
LeClair outlined three key features of infrared technology which can be used to sell customers on the methodology:
- Seamless outcome as joints are fused hot material against hot material.
- Clean results with almost no waste.
- Less traffic or public disruption due to speed of repairs
Kieswetter added that “infrared asphalt repair leaves sealed watertight joints for longer durability of a repair patch. The repair requires less equipment on the site, and is quiet and less intrusive.”
Since infrared repairs utilize in-place recycling of existing asphalt, it means the solution is environmentally friendly, and can be described as being a “green technology.”
A big benefit of infrared repair technology is how quickly repairs can be made.
“If you are working with a commercial customer on a parking lot you can perform a repair in about 1/3 the time as traditional methods resulting in less disruption to traffic flow,” Blake said. “Additionally, in most cases, infrared is a more cost-efficient option.”
With any technology, there are those that prefer not to use it. Although, the naysayers are often acting on a lack of knowledge.
“The biggest objection to infrared technology is the mistaken opinion that it damages the asphalt,” stated Kieswetter. “This opinion stems from much earlier attempts at recycling asphalt in-place by using indirect hot flame that scorches the surface before it achieves penetration and/or existing infrared users that do not use sufficient care in monitoring the temperatures.
“When re-heating, it is important to ensure the surface temperature stays at a reasonable temperature while the full depth of the wear course being repaired is heated sufficiently to rework. Theoretically, the light oils in the bitumen start to burn off at 270F(170C). In original production at an asphalt plant, temperatures will generally be much more than that, but they can compensate for that in the mix design to ensure that the final mix meets specification. When exceeding these temperatures during infrared work we have the advantage that the duration of the high temperature is much less than new mix, and we always add a rejuvenator to partially compensate for temperature exceedance, as well as oxidation (hardening) of the upper surface that has happened over time. Still, the rule when doing infrared is: White smoke is just water vapor from moisture trapped in the cracks, black smoke means you are burning off the light oils.”
Blake offered this on the biggest objections to infrared technology and how best they can be countered: “The biggest objection is often customers’ lack of knowledge on the infrared process. When you mention infrared to a potential customer they may be completely unfamiliar with the process and technology, so it falls on you as the contractor to educate them and sell them on why infrared is an effective and efficient repair.”
If Sir William Herschel were around today, he’d be pleased to see the practical applications and beneficial uses of his discovery. Infrared asphalt repair is certainly a beneficial application.
Jeff Winke is a business and construction writer based in Milwaukee, Wisconsin. He can be reached through firstname.lastname@example.org