The Waukesha County roads that are part of this project are about 7-8" thick. It can be costly and time-consuming to tear out an entire existing road and pave back in that thick. It was determined by Waukesha County Engineering that removal of 6” of the existing pavement and patching distressed areas would be necessary. Those areas are milled 6” deep and an asphalt mix designed for Waukesha County is paved in two layers with nuclear density testing to make sure it is the right density and performs properly over time.
To save costs over traditional paving of a first binder layer, hot-in-place recycling can be done, a sustainable and eco-friendly asphalt paving method.
Waukesha County decided that hot in place recycling would be the best option, and Wolf Paving partnered with Gallagher Asphalt.
Hot-in-Place asphalt recycling consists of using heating elements gently heat, rejuvenate and re-pave the existing material to reuse the existing road. The road is heated to approximately 350 degrees using 2 propane-fired heating elements, the temperature based on the depth in which you are working. A series of applicator-distributing discs follows the ovens that apply rejuvenating polymer oil to the asphalt. Next the scarifying teeth dig into the road to blend the rejuvenating oils with the heated road. At the end, a paving screed makes asphalt smooth and flat again, and a roller compacts the asphalt. Once the recycled road is finished, it is left to cure for around a week, after which the final surface layer of new asphalt is applied.