Problems in obtaining the correct mat surface finish can be traced to several different sources.
- 1. Improper mix control - improper temperature control, unstable mix, improperly graded mix, etc.
- 2. Improper rolling of the mat - not enough, too much, too soon, too late, etc.
- 3. Improper adjustment of the paver - too much lead crown, too little lead crown, vibrator speed wrong, etc.
- 4. Improper operation of the paver - paving too fast, paving too slow, running paver out of material, etc.
- 5. Improper preparation of the surface on which the mat is laid.
- 2. Improper rolling of the mat - not enough, too much, too soon, too late, etc.
A center segregation spoiler is available for use when segregation or mat streaking in the center of the screed occurs. The spoiler is intended to reduce the possibility of segregation when paving thin lifts of 5/8 inch (15.88 mm) or less and when using larger aggregate mixes with a low percentage of fines.
The following trouble shooting charts will help in locating the cause of mat defects and in correcting the cause.
Mat Not Compacted Properly
Screed Marks In Mat
Wavy Surface (Long Waves)
Wavy Surfaces (Short Waves)
Bad Longitudinal Joint
Bad Transverse Joint
Surface Cracks In Center Of Strip
Streak In Center Of Strip
Transverse Hairline Cracks In Surface
Deep Transverse Cracks Full Width
Tearing - All Across Mat
Surface Cracks At Edges
