Durability Cracking

Durability cracking (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 ft (0.3 to 0.6 m) of the joint or crack.

Severity Distress Example Description
Low Close-up photo showing a corner where four PCC slabs come together. All four slab corners           in the photo show a series of crescent-shaped D-cracks. The cracks are all tight with no visible spalling. "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). Little or no disintegration has occurred. No FOD potential.
Medium Overview photo showing a transverse joint. The majority of the length along the joint shows D-cracking with noticeable spalling. One of the following conditions exists: (1) "D" cracking has developed over a considerable amount of slab area with little or no disintegration or FOD potential; (2) "D" cracking has occurred in a limited area of the slab (such as one or two corners or along one joint), but pieces are missing, and disintegration has occurred. Some FOD potential.
High Close-up photo of a transverse joint with high-severity D-cracking. The photo shows D-cracking at a good distance away from joint, and many of the cracks within the D-cracking pattern are spalled. "D" cracking has developed over a considerable amount of slab area, and has resulted in disintegration or FOD potential.