Durability Cracking

Durability cracking (ā€œDā€ cracking) is caused by freeze-thaw expansion of the large aggregate, which, over time, gradually breaks down the concrete. This distress usually appears as a pattern of cracks running parallel and close to a joint or linear crack. Since the concrete becomes saturated near joints and cracks, a dark-colored deposit can usually be found around fine ā€œDā€ cracks. This type of distress may eventually lead to disintegration of the entire slab.

Severity Description
Low "D" cracking covers less than 15% of slab area. Most of the cracks are tight, but a few pieces may be loose and or missing.
Medium One of the following conditions exists: "D" cracking covers less than 15% of the area and most of the pieces are loose and or missing, or "D" cracking cover more than 15% of the area. Most of the cracks are tight, but a few pieces may be loose and or missing.
High "D" cracking cover more than 15% of the area and most of the pieces have come out or could be removed easily.