TM 5-826-6/AFR 93-5
- Nonfilled cracks of any width with faulting >3/8 inch or medium severity spalling.
- Filled cracks of any width with faulting > 3/8 inch or high severity spalling.
(4) Counting procedure. Once the severity has been identified, the distress is recorded as one slab.
t. Durability ("D") cracking, distress 64.
(1) Description. D cracking is caused by the concrete's inability to withstand environmental factors such as
freeze-thaw cycles. It usually appears as a pattern of cracks running parallel to a joint or linear crack. A dark coloring can
usually be seen around the fine durability cracks. This type of cracking may eventually lead to disintegration of the
concrete within 1 to 2 feet of the joint or crack.
(2) Severity levels.
(a) Low severity level (L). D cracking is defined by hairline cracks occurring in a limited area of the slab,
such as one or two corners or along one joint, and where little or no disintegration has occurred, or no FOD potential exists
Figure A-83. Low severity D cracking.
(b) Medium severity level (M). D cracking has developed over a considerable amount of slab area with
little or no disintegration or FOD potential; or D cracking has occurred in a limited area of the slab, such as in one or two
corners or along one joint, but pieces are missing and disintegration has occurred with some FOD potential (figs. A-84