L - “D” cracks cover less than 15 % of slab area. Most of the cracks are tight, but a few pieces may be loose and or missing.

M - One of the following conditions exists: “D” cracks cover less than 15 % of the area and most of the pieces are loose and or missing, or “D” cracks cover more than 15 % of the area. Most of the cracks are tight, but a few pieces may be loose and or missing.

H - “D” cracks cover more than 15 % of the area and most of the pieces have come out or could be removed easily.