Pavement Inspection

Corner Break

A corner break is a crack that intersects the joints at a distance less than or equal to one half of the slab length on both sides, measured from the corner of the slab. For example, a slab with dimensions of 25 by 25 ft (7.5 by 7.5 m) that has a crack intersecting the joint 5 ft (1.5 m) from the corner on one side and 17 ft (5 m) on the other side is not considered a corner break; it is a diagonal crack. However, a crack that intersects 7 ft (2 m) on one side and 10 ft (3 m) on the other is considered a corner break. A corner break differs from a corner spall in that the crack extends vertically through the entire slab thickness, while a corner spall intersects the joint at an angle. Load repetition combined with loss of support and curling stresses usually causes corner breaks.

Severity Distress Example Description
Low Overview photo showing a corner where four PCC slabs come together. Three of the four slabs in the photo have low-severity corner breaks. Each corner break is a fairly tight, single, non-spalled crack. Crack has little or minor spalling (no FOD potential). If non-filled, it has a mean width less than approximately 1/8 in (3 mm). A filled crack can be of any width, but the filler material must be in satisfactory condition. The area between the corner break and the joints is not cracked.
Medium Overview photo of a PCC slab corner with a single corner break crack. The crack in the photo is noticeably spalled. One of the following conditions exists: (1) filled or non-filled crack is moderately spalled (some FOD potential); (2) a non-filled crack has a mean width between 1/8 in to 1 in (3 and 25 mm); (3) a filled crack is not spalled, or is only lightly spalled, but the filler is in unsatisfactory condition; (4) the area between the corner break and the joints has only one low-severity crack dividing the corner into two pieces.
High Close-up photo of a PCC slab corner with a high-severity corner break. The corner break is broken into two pieces, has considerable spalling, and has noticeable faulting. One of the following conditions exists: (1) filled or non-filled crack is severely spalled, causing definite FOD potential; (2) a non-filled crack has a mean width greater than approximately 1 in (25 mm), creating a tire damage potential; (3) the area between the corner break and the joints is divided into three or more pieces by two or more cracks, one of which is at least high severity.