Light: Cracks, usually only transverse, are less than 1/4 inch wide and are not spalled; block pattern may not be visible yet; sealant is satisfactory if cracks have been sealed; transverse cracks usually 10 to 20 feet apart.

Moderate: Block pattern may be visible with blocks 10 square feet or greater present; cracks are 1/4 inch wide to less than 1/2 inch wide; cracks may or may not be spalled; transverse cracks usually 5 to 20 feet apart.

Severe: Cracks may be severely spalled with smaller blocks 2 to 10 square feet present; cracks usually about 1/2 inch wide or greater; transverse cracks may be 1 to 2 feet apart throughout portions of the surface.

Description: Block cracks divide the pavement up into roughly rectangular pieces. Block cracking is not load-associated. Cracks are generally caused by shrinkage of the asphalt concrete and daily temperature cycling. Wheel path loads can increase the severity of block cracking if water is allowed to penetrate into the cracks. It is therefore very important to seal these cracks to prevent water penetration into the base materials.

* Transverse cracking also includes reflective cracking, plant mix resurfacing over concrete.

The primary causes of reflective cracking are movement of the concrete slab beneath the PM resurfacing because of thermal and moisture changes and faulting at joints. Typically, the reflective joints are bulged above the riding surface such that the vehicle is riding over small bumps.

TRANSVERSE CRACKING (REFLECTIVE)

(Overall Condition)