After some success in the process of recycling asphalt pavements in 1975, Kossuth County decided to implement further recycling projects on a larger scale in its 1976 road construction program. The work done in 1975 indicated that a quality product could be produced, but that an air pollution problem created during the heating and mixing operation must be brought under reasonable control. As part of its 1976 road program, Kossuth County planned to salvage a total of 16 miles of old asphalt pavements in three projects. Two of these projects were three miles in length and the third project was ten miles long. The ten mile project was selected by the Federal Highway Authority as one of the recycling projects to be completed in cooperation with Demonstration Project No. 39, Recycling Asphalt Pavements.

This report describes a project in which approximately 6,200 tons (5,630 Mg) of asphaltic concrete were recycled through a conventional asphalt batch plant. During the construction of the project, a buildup of asphalt-coated fines occurred in the dryer and the dust collector. The buildup is thought to have been associated with the fineness and/or the high asphalt content of the recycled mix. To solve the problem, a change was made in the recycling process. The project was completed using a heat transfer method with mix proportions as high as 50% recycled material added to 50% virgin aggregate.

This report describes a project in which approximately 6,200 tons (5,630 Mg) of asphaltic concrete were recycled through a conventional asphalt batch plant. During the construction of the project, a buildup of asphalt-coated fines occurred in the dryer and the dust collector. The buildup is thought to have been associated with the fineness and/or the high asphalt content of the recycled mix. To solve the problem, a change was made in the recycling process. The project was completed using a heat transfer method with mix proportions as high as 50% recycled material added to 50% virgin aggregate.