Figure B-22. Medium-severity corrugation.
Figure B-21. Medium-severity corrugation.
H-Corrugation produces high-severity ride quality (fig B-23).
How to Measure:
Corrugation is measured in square feet of surface area.
Name of Distress:
Localized pavement surface areas with elevations slightly lower than those of the
surrounding pavement are called depressions. In many instances, light depressions
are not noticeable until after a rain, when ponding water creates "birdbath" areas; on
dry pavement, depressions can be spotted by looking for stains caused by ponding
water. Depressions are created by settlement of the foundation soil or are a result of
improper construction. Depressions cause some roughness, and when filled with
water of sufficient depth, can cause hydroplaning. Sags, unlike depressions, are
abrupt drops in elevations.
Maximum depth of depression:
L-1/2 to 1 inch.
M-1 to 2 inches.
H-more than 2 inches.
See figures B-24 through B-26.
Figure B-24. Low-severity depression.
Figure B-23. High-severity corrugation.