15 March 2001
DISTRESS 50, PATCHING AND UTILITY CUT PATCH
12.1. Description. A patch is considered a defect, regardless of how well it is performing.
Deduct curves for patching and utility cut patches are shown in Figure 12.1.
12.2. Severity Levels.
12.2.1. L. Patch is in good condition and is performing satisfactorily (Figures 12.2. and 12.3.).
12.2.2. M. Patch is somewhat deteriorated and affects riding quality to some extent (Figure
12.2.3. H. Patch is badly deteriorated and affects riding quality significantly or has high FOD
potential. Patch needs replacement (Figure 12.5.).
12.3. Porous Friction Courses.
in PFC surfaces causes
a water damming effect at the patch that contributes to differential skid resistance of the surface.
Low-severity, dense-graded patches should be rated as medium severity because of the
differential friction problem. Medium- and high-severity patches are rated the same as above.
12.4. How to Measure. Patching is measured in square feet (square meters) of surface area.
However, if a single patch has areas of differing severity levels, these areas should be measured
and recorded separately. For example, a 25-square-foot (2.3-square-meter) patch may have 10
square feet (1.0 square meter) of medium severity and 15-square-feet (1.4-square-meters) of
light severity. These areas would be recorded separately. Any distress found in a patched area
will not be recorded; however, its effects on the patch will be considered when determining the
patch's severity level.