The Ideal Asphalt Recycling Method

Asphalt is in most cases recycled and according to recent survey, only 1% of the asphalt is actually disposed in landfills. Recycled asphalt, also known as recycled asphalt pavement (RAP), is removed and reprocessed pavement material that contain asphalt and aggregate. The RAP is obtained by a road recycler that crushes, rips or mills pavement and combines it with asphalt or aggregate. The result is hot mix asphalt (HMA).

If proper asphalt recycling method and quality road recycler are used, the recycled asphalt pavement will certainly be of high-quality and well-graded aggregate. This process is cost-effective and shows potential to produce quality RAP, so it is a valuable rehabilitation alternative. As there are few types of road recycler, there are also few methods of recycling asphalt. We’ve decided to tell you more about the ideal method of recycling asphalt – center entry method.

Center Entry Method

The center entry method is the most used technique for hot mix recycling in a drum mix asphalt recycling plant. With this method, the recycled asphalt pavement goes into a drum to be mixed with new aggregates. The RAP is safe in the drum from direct contact with the burner frame, which is important to ensure. If not, the RAP can overheat and result in so-called blue smoke. It will thus be unusable. There are several modified types of drum mix asphalt recycling plant, invented to fix the problem with the emission. In fact, those alternative methods eliminate the exhaust gas stream, which indirectly eliminates the emission of light ends to the bag-house.

There are also different types of drum mix asphalt recycling plant. One common asphalt recycling plant is the parallel-flow drum mixer which has an isolated mixing area and a dryer shell which rotates along with the dryer. The dryer removes the gas stream before recycled asphalt pavement enters the isolated mixing area. The parallel-flow drum mixer has reduced hydrocarbon levels, so the new liquid asphalt can be shielded from direct exposure to the gas stream. Another type of parallel-flow dryer drum is when the RAP is introduced in a separate mixing device and is then heated in the mixing device. The percentages of recycled asphalt pavement in this type of asphalt recycling plant are affected by the physical space.