TM 5-826-6/AFR 93-5
Figure A-26. High seventy joint reflection cracking.
(3) Measuring procedure. Joint reflection cracking is measured in linear feet. The length and severity level of
each crack should be identified and-recorded. If the crack does not have the same severity level along its entire length,
each portion should be recorded separately. For example, a crack that is 50 feet long may be 10 feet of a high severity
cracking, 20 feet of a medium severity, and 20 feet of a light severity. These would all be recorded separately.
h. Longitudinal and transverse cracking (non-PCC joint reflective), distress 48.
(1) Description. Longitudinal cracks are parallel to the pavement's center line or laydown direction. They may
be caused by (a) a poorly constructed paving lane joint, (b) shrinkage of the AC surface due to low temperatures or
hardening of the asphalt, or (c) a reflective crack caused by cracks beneath the surface course, including cracks in PCC
slabs (but not at PCC joints). Transverse cracks extend across the pavement at approximately right angles to the
pavement's center line or direction of laydown. They may be caused by items b or c above. These types of cracks are not
usually load-associated. If the pavement is fragmented along cracks, the crack is spalled.
(2) Severity levels.
(a) Low severity level (L).
- Cracks have either minor spalling with no loose particles (little or no FOD potential) or no spalling.
The cracks can be filled or nonfilled. Nonfilled cracks have a mean width of 1/4 inch or less. Filled
cracks are of any width, but their filler material is in satisfactory condition (figs. A-27 and A-28).
- For porous friction courses, the average raveled area around the crack is less than -inch wide (fig.
A-29).
A-19
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