Cracks that run across the road roughly at right angles to traffic, often at fairly regular spacing, formed when the pavement cools so fast and so far that the binder can no longer relax the shrinkage stress. It is the failure the low-temperature PG number and the BBR test are meant to prevent, and it gets worse as binder ages. Water entering the cracks can cause depressions and cupping at each crack in freeze-thaw country.
Thermal cracking every forty feet on the old 58-28 overlay, that binder's aged out and gone brittle.
Also heard as
- transverse cracking
- low-temperature cracking
Related terms
BBR
Bending beam rheometer: the test that checks how stiff and brittle a binder gets at low temperature.
PG
Performance Grade: the binder rating that names the hottest and coldest pavement temperatures a binder can handle.
Reflective cracking
Cracks in an overlay that mirror the cracks or joints in the old pavement underneath.