CLAMP 1713745 - Caterpillar

Mat Finish Problems
Problems in obtaining the correct mat surface finish can be traced to several different sources.* Improper mix control - improper temperature control, unstable mix, improperly graded mix, etc.* Improper rolling of the mat - not enough, too much, too soon, too late, etc.* Improper adjustment of the paver - too much lead crown, too little lead crown, vibrator speed wrong,etc.* Improper operation of the paver - paving too fast, paving too slow, running paver out of material, etc.* Improper preparation of the surface on which the mat is laid.The following troubleshooting procedures will help in locating the cause of mat defects and in correction the cause.Troubleshooting Index
1. Mat not compacted properly.2. Screed marks in mat.3. Wavy surface (long waves).4. Wavy surface (short waves).5. Bad longitudinal joint.6. Bad transverse joint.7. Surface cracks in center of strip.8. Streak in center of strip.9. Transverse hairline cracks in surface.10. Deep transverse cracks full width.11. Tearing - all across mat.12. Surface cracks at edges. 1. Mat Not Compacted Properly Cause: Vibrator 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. 2. Screed Marks in Mat Cause: Brakes set on truck. Correction: Instruct truck driver. Cause: Truck bumping paver. Correction: Instruct truck driver. 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: Segregation of materials in mix. correction: Correct at plant. Cause: Hopper doors opened too much. Correction: Close the hopper doors more. Cause: Auger flighting worn. Correction: Replace flighting. Cause: Waiting a long time between loads. Correction: Correct at plant or trucks. Reduce paving speed. 4. Wavy Surface (Short Waves) Cause: Poor mix temperature control. Correction: Correct at plant or trucks. Cause: Over controlling screed. Correction: Allow time for screed to react between adjustments. Cause: Segregation of materials in mix. Correction: Correct at plant. Cause: Too much slack in roller drives. Correction: Repair/replace roller. Cause: Auger flighting worn. Correction: Replace flighting. 5. Bad Longitudinal Joint Cause: Not rolling soon enough. Correction: Instruct roller operator. Cause: Over controlling screed. Correction: Allow time for screed to react between adjustments. Cause: Poor mix temperature control. Correction: Correct at plant or trucks. Cause: Screed end gate not positioned properly. Correction: Adjust end gate. Cause: Too much or too little overlap. Correction: Decrease or increase overlap. 6. Bad Transverse Joint Cause: Auger initially loaded too high. Correction: Do not overload auger at start of operation. Cause: Joint not rolled soon enough. Correction: Instruct roller operator. Cause: Poor preparation for joint. Correction: Prepare joint properly. Cause: Screed too cold. Correction: Warm screed before