DIFFERENTIAL GP 8W5587 - Caterpillar

Mat Finish Problems
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.A center separation spoiler is available for use when separation or mat streaking in the center of the screed occurs.The spoiler is intended to reduce the possibility of separation when paving thin lifts of 15.8 mm (5/8 in) or less and when using larger aggregate mixes with a low percentage of fines.The following troubleshooting procedures will help in locating the cause of mat defects and in correction the cause.1. Mat Not Compacted Properly2. Screed Marks in Mat3. Wavy Surface (Long Waves)4. Wavy Surface (Short Waves)5. Bad Longitudinal Joint6. Bad Transverse Joint7. Surface Cracks in Center Of Strip8. Streak in Center of Strip9. Transverse Hairline Cracks in Surface10. Deep Transverse Cracks Full Width11. Tearing - All Across Mat12. Surface Cracks at Edges 1. Mat Not Compacted Properly Cause: Vibrators running too slow. Correction: Increase vibrator speed. Cause: Screed not completely lowered. Correction: Lower screed. Cause: Mix graded improperly. Correction: Correct at plant. Cause: Poor mix temperature control. Correction: Correct at plant or trucks. Cause: Soft base. Correction: Check base before starting paving operation. Cause: Automatic feeder control not properly adjusted. Correction: Adjust position of feeder control sensor paddles. 2. Screed Marks in Mat Cause: Brakes set on truck. Correction: Instruct truck driver. Cause: Truck bumping paver. Correction: Instruct truck driver. Cause: Automatic feeder control. Correction: Visually check operation of feeder control. Troubleshoot if necessary. Cause: Waiting a long time between loads. Correction: Correct at plant or trucks. Reduce paving speed. 3. Wavy Surface (Long Waves) Cause: Over controlling of screed. Correction: Allow time for screed to react between adjustments. Cause: Poor mix temperature control. Correction: Correct at plant or trucks. Cause: Running material too low between loads. Correction: Reduce paving speed. Cause: Poor grade reference (using grade control). Correction: Improve or change reference. Cause: Screw conveyors loaded too high. Correction: Adjust automatic feeder control. Cause: Head of material fluctuating. Correction: Adjust automatic feeder