1. WAPA / WSDOT Joint Training
SCREED PREPERATION AND CORRECTIONS
on THIN LIFT APPLICATIONS
TRACY LAMBERT

2. BEFORE YOU START PAVING
Job site preparation, whether its milling, dig outs, pre-levels or tacking. These should be in the ready before paving.
Paving equipment. Is your paver properly set up for the job - screed in adjustment, extensions on if needed, grade or joint matching automation functioning properly?
If you using a transfer device shuttle buggy or pick up machine are they adjusted properly?
Do you have the correct compaction equipment?
Does your crew understand the job layout?

3. JOB SITE PREPERATION IS KEY
Is the surface even and free of uneven areas?
Did you overlook anything?

4. IS YOUR PAVER IN GOOD OPERATING CONDITION?

5. IS THE SCREED IN PROPER ADJUSTMENT AND MAINTAINED?
PRE-STRIKE OFFS: SHOULD MEASURE ½ INCH ABOVE THE MAIN.
EXTENSION SLIDES AND SUPPORTS PROPERLY TIGHTENED.
END GATES CLEANED AND MAINTAINED.
SCREED HEAT FUNCTIONED AND TESTED FOR PROPER HEAT.
LUBRICATION POINTS ATTENDED TO.

6. IS YOUR SCREED THE RIGHT ONE FOR THE JOB?
Rear mount extensions
Front mount extensions

7. IS YOUR SCREED SET UP WITH THE PROPER ATTACHMENTS?

8. ARE THE ATTACHMENTS PROPERLY INSTALLED?

9. DON’T BE AFRAID TO CHECK YOU SCREED ADJUSTMENT DURING PRELEVEL

10. FROM THE GROUND IT LOOKS PERFECT

11. CHANGE YOUR VIEW POINT

12. Identifying Mat Imperfections and Causes
End gate is too Low
Set the bottom of the shoe to the same height as the bottom of the screed prior to start.
Extensions are too Low causing the screed to ride on them leaving the center of the mat loose. Adjust your extensions to match the main screed.
In most cases these marks will roll in with compaction but still leave cosmetic flaws in the mat.

13. MAKING SCREED CORRECTIONS
Making corrections to your screed for match height, width or angle of attack should always be made while the machine is in motion.
Allow yourself time to see the corrections before making another. In some cases this could take up to three tow arm lengths.
Slow and small changes will get you the best results.

14. AFTER COMPACTION (and some traffic)

15. ON THIN LIFT APPLICATIONS MAKE CORRECTIONS QUICKLY

16. EXCEPT IF YOU HAVE THIS THEN YOU START OVER

17. CONTROLLING THE HEAD OF MATERIAL
We have found by controlling the head of material across the entire screed width allows for a more consistent mat
The use of tunnel confinement devices allow for better head control in wide width paving and it also improves production time.

18. CONTROLLING THE HEAD OF MATERIAL
Overfilling the screed causes the screed to work harder to maintain the proper thickness.
And especially on thin lift paving this could cause minor imperfections on the surface of the mat surface to be more noticeable.

19. CHECK THE ANGLE OF ATTACK ON YOUR MAIN SCREED
The screed should be riding on at least ¾ quarters of the screed plate.
This will give you longer life on the plate and a smoother finish.

20. IF YOU DON’T THEN YOU’RE JUST BULLDOSING ASPHALT

21. THIN LIFT PAVING JOINT MATCHING
Joint matching on thin lift paving is an art. Because of the thickness you may find yourself experimenting with your attachment to get the proper setting.
The use of a vibratory sled attachment may be not needed.

22. THIN LIFT PAVING JOINT MATCHING
But with the proper tools and patience you can get great looking (and performing) joints.
Achieving proper joint density on any paving job is one of our greatest challenges.

23. SAFETY EDGE OR ASPHALT EDGE TREATMENT DEVICE
It has become more common in our business that the DOTs are asking for the edge of the panels to be beveled to allow for safer transitions back on to the highway.
On thin lift applications this could mean you will need to run out past the your desired width or further than that pass was planned for.

24. We live in one of the most beautiful places in the world
We live in one of the most beautiful places in the world. So lets all be safe out there so we can enjoy it.