ForConstructionPros.com

Asphalt producers/contractors continue to leverage the value of reclaimed asphalt pavement (RAP) by investing in equipment to process that resource to be incorporated in new mixes for commercial and state agency customers. Rising material costs -- both virgin aggregate and liquid asphalt cement binder -- have encouraged both producers and customers to consider the cost-savings benefit of RAP mix designs.

Many state department of transportation agencies have gained an increased acceptance of RAP designs, realizing they not only save money and expand budgets, but also that they perform as well as virgin mix designs.

For most asphalt production operations, a horizontal shaft impactor and screen to size material is all that's needed to process old asphalt. Milled RAP material can quickly be processed with a screen, with 80% of the millings passing through the ½-inch minus openings.

Larger material can then be moved through a closed-circuit conveyor system to a crusher for further processing before being returned to the screen. A horizontal crusher will sufficiently break down larger particles without crushing the aggregate content.

For asphalt producer/contractors who want better control over their ability to add maximum RAP content to their mix designs, a crushing/screening system that fractionates (separates) the material components of the RAP is considered the best way to go.