Raveling: Raveling is the
progressive disintegration of pavement from the top down as the result of the
loss of individual aggregate particles. The surface loses its smoothness and
begins to look coarse. Loose sand and pebble-size aggregates appear on the
pavement surface.
Alligator or fatigue cracking:
Vertical movement under traffic
loads cause a large amount of tension, or pulling apart, of the pavement. The
result is fatigue or alligator cracking. The pattern is similar to alligator
skin or chickenwire fencing.
Block cracking/Shrinkage cracks: Cracks in this type of
pattern usually intersect each other at nearly right angles. The pattern may
start out at a 20-foot spacing and with time could advance into a much smaller
spacing, perhaps as small as 1 foot.
