The success of HIR is dependent on a good structural section and the adequacy of the selected treatment to restore the viscosity of the aged binder and mitigate the existing distress. In short: you cannot treat what you cannot reach.
The HIR processes are not meant to address structural failures of the pavement such as structural rutting or existing mixture instability. HIR is meant to treat non-load associated distresses and minor structural distresses that occur in the top 1-3 inches of the pavement structure and can slow the return of transverse or reflective cracking.
Type of Distress
Oxidation, poor ride quality, deformations, raveling or minor cracking
Potholes, rutting, reflective cracking
Transverse cracking, deep rutting, stripping
Depth of Distress
Within treatment depth
Within 1-2 inches of treatment depth
Beyond treatment depth
EXAMPLES OF ROADS THAT HAVE BEEN TREATED WITH Hot In-Place Recycling OVER VARIOUS STAGES IN SERVICE LIFE: