Following the establishment of a proper grade through grinding and the addition of water or additives, the material is ready for compaction. The best tool to use for this step is a padfoot roller.

Padfoot rollers are ideally suited for the compaction of cohesive soils. Because of the basic properties of asphalt and its presence within the mix, the material tends to have the properties of a cohesive soil. Padfoot rollers work well because they compact unevenly, preventing material layering and establishing a good mix of material.

During the first pass, the pads of the roller typically sink all the way down to the drum. But as compaction increases, the pads begin to "walk out" or rise up out of the mix as the material achieves density. Eventually, the roller will be standing near the tips of the padfoot, indicating that proper compaction has been established. It is important to remember that if the material becomes misshapen during the compaction process, the use of a motor grader is advised for any required reshaping. Additionally, when compaction is established, the grader should be used to remove any of the "uncompactable" materials, or ravel, from the surface. Finally, a rubber-tired or steel-drum roller is used to smooth and finish the recycled base.

After the road has been mixed, shaped and compacted, it should then be protected by some form of temporary seal. A fog seal is an asphalt emulsion that applies to the top of the base and allows water to shed off the top instead of soaking in and compromising the integrity of the compacted base that has been achieved.

After the sealant has been applied, the newly established base is ready for an overlay, chipseal or whatever is specified for the job. If an additive was not used during recycling, the finishing treatment can be applied shortly after completion. If an additive was used, typically time must be allowed for the substance to cure. This extra time needed between recycling and the finishing treatment makes the sealing step even more important to maintain the integrity of the compacted material.

The Benefits
So if one is already familiar with conventional reconstruction, why even consider a "new" process, such as full-depth asphalt recycling? The answer is simple - money. Cost savings are the single greatest benefit of asphalt recycling. And the savings all boil down to an eliminated piece of equipment - the truck. With conventional road reconstruction, the entire road must be excavated and trucks are used to haul existing materials away. Following excavation, trucks are required again to haul new, or processed, materials to the site to rebuild the road from the bottom up. Simply the overall logistics of excavation and hauling translates into much more time to reconstruct the road, resulting in added expense. Compounding the expense of additional time in the process is the necessity of utilizing the trucks themselves to haul the material.

A third cost-increasing factor associated with standard reconstruction is the recycling cost of removed materials. Old materials must be sent off to the recycling center and eventually reused. This typically involves stripping the asphalt off the top of the road, shipping it to a pug mill, adding materials to make new asphalt and then shipping back to the job site. Though it is an effort to save money for materials, the cost to haul it alone, in most cases, eliminates the savings. On the other hand, full-depth asphalt recycling, which is essentially total reconstruction of a road, encounters few of these cost-prohibitive problems. Material costs are less because the existing material is recycled and reused. Though many times additional aggregate or asphalt must be added to create a proper base, this is much more cost effective than removing the road bed. Additionally, the material is recycled in-place, meaning there is little need for excavation or hauling.

In the end, full-depth asphalt recycling costs anywhere from one-third to one-half of the total cost incurred for conventional reconstruction. And when done properly, recycling has offered better results than conventional reconstruction.