What is a Heater-Scarifier?

A heater-scarifier, used to loosen and heat the existing asphalt surface, is one technique of hot in-place recycling of asphalt concrete. This pretreatment improves the quality of the overlay. More details can be found at the websites listed below.

A few points to remember if using hot in-place recycling with a heater-scarifier:

• Be sure not to rush. Going too fast may damage the asphalt.
• The maximum depth is 2 inches and typically only 1-½ inches.
• Plan on about 1.5 lane-miles per day of recycling.

Remember, the base and subgrade are not improved. If there is an underlying problem in-place recycling is not the correct technique. Total reconstruction or full depth reclamation may be better techniques. You may be able to box out a few bad spots before recycling a much longer stretch.

References

Asphalt Emulsion Manufacturers Association

National Center for Pavement Preservation

Highway Rehab Corporation (www.highwayrehab.com)

February, 2009