Fine transverse cracks, usually 1 to 3 inches long and a few inches apart, that appear on the surface as rollers pass over the fresh mat. They show the mix is moving under the drum instead of compacting, from a tender mix, excess fines or moisture, a binder too soft at that temperature, a slick tack layer, or a roller that is too heavy or too early. Light checks often close under a pneumatic roller, but they still point to a mix or rolling problem.
Mat's checking under the breakdown roller, back off the vibe and get the rubber tire on it to close it up.
Also heard as
- checks
- check cracking
- roller checking
Related terms
Tender mix
Mix that shoves and moves under the rollers instead of compacting, often within a certain temperature range.
Breakdown roller
The first roller behind the paver, which does most of the compaction while the mat is still hot.
Pneumatic roller
A rubber-tired roller whose offset tires knead the mat, closing surface voids during intermediate rolling.
Fines
The dust-sized part of the aggregate passing the No. 200 sieve, which stiffens the binder into a mastic.