• Hot in-place recycling (HIPR). HIPR can usually remedy surface distress problems. HIPR can be done by heater scarification, repaving or remixing.
Heater scarification. The pavement surface is heated with radiant heaters, scarified using a bank of non-rotating teeth, rejuvenated using an additive to improve the recycled asphalt binder viscosity, mixed and leveled, then compacted using conventional compaction equipment.
Repaving. This method is similar to heater scarification, only the top layer is completely removed (rather than left in place) and then placed in either one or two lifts.
Remixing. This method is used when additional aggregate is required to improve the strength or stability. Remixing is similar to repaving but adds new virgin aggregate or new HMA to the recycled material before it is leveled.
• Cold in-place recycling (CIPR). CIPR essentially pulverizes the existing pavement structure to a predetermined depth, adds a binding agent (such as an emulsion or foamed asphalt), then lays and compacts the resulting product for use as a stabilized base course.
*KAPA Pavement Note on Structural Overlays
The Asphalt Institute's Asphalt Overlays for Highway and Street Rehabilitation (MS-17), provides design procedures for component analysis and non-destructive testing with limiting deflection criteria.
Structural overlays are used to increase pavement structural capacity. Therefore, they are considered rehabilitation, although they have maintenance-type benefits as well.
*KAPA Pavement Note on Rehabilitation
A wholesale replacement of the entire pavement structure is considered reconstruction rather than rehabilitation since it follows new pavement construction methods.