Hot in-place recycling is an on-site, in-place method that rehabilitates deteriorated bituminous pavements and thereby minimizes the use of new materials. This process may be performed as either a single pass (one phase) operation that monolithically recombines the restored pavement with virgin material, or as a two pass procedure, wherein the restored material is recompacted and the application of the new wearing surface then follows a prescribed interim period that separates the process into two distinct phases.
Hot in-place recycling provides a very low cost maintenance strategy that enables the public works official to effectively re-use existing materials. This process demonstrates that asphalt is a rather unique construction material in that it can be effectively and economically restored. Rather than bury the deteriorated pavement with inordinate depths of new material conventionally applied, or lose it to the grinder, proponents of Hot In-Place Recycling encourage restoration.
Hot in-place recycling effectively addresses the classic symptoms of deteriorated pavement:
- Cracks are interrupted and filled.
- Aggregate stripped of the bitumen is remixed and recoated.
- Ruts and holes are filled, shoves and bumps are leveled, drainage and crowns are re-established.
- Flexibility is restored by chemically rejuvenating the aged and brittle pavement.
- Aggregate gradation and asphalt content may be modified by some variations of this process.
- Highway safety is enhanced through improved skid resistance.
In a period of rapidly increasing costs and limited funding, Hot in-place recycling presents the opportunity to spread available dollars over a much greater area. Roadway deterioration can be suspended, pavements preserved and upgraded, and costly reconstruction avoided.