1. Extending Performance with Proper Asphalt Compaction
Ken Walschlager
Milestone Contractors

2. Compaction is 90% rolling – the other half is preparation…
Compaction is the process of reducing the volume of a mass of material – making it more dense.
Design
Proper production
Sub-base/drainage
Good paving practices
Lift thickness

3. Compaction is key… Better Compaction results in…
Extended pavement’s life of service
Greater strength to support heavier loads
Increased resistance to rutting
Reduced permeability of water and air
Overall durability

4. Proper HMA Design Different designs for different applications
Special mix designs OG
Porous
SMA
4.75 Thin Lift
What about Warm Mix?

5. Proper Depth
Back to design…

6. Proper Production Stockpiles built correctly and tested?
Loader using correct methods?
Plant calibrated?
Right blend entered?
Proper loading of haul trucks?
Trucks equipped with tarps?

7. Proper Laydown Surface properly prepared/tacked?
Mix dumped properly into buggy/paver?
Hopper not run empty?
Flow gates/auger speed set correctly?
Proper head of material?
Auger height correct/constant motion?
Paver operated at constant speed?
Depth as uniform as possible?

8. Proper Depth – it’s important
Deep enough for aggregate structure

9. Before rolling operations begin
Proper maintenance – read operators manual
Operator Safety – get familiar with roller
Check water system
Release agent?
Confirm frequencies

10. Rollers Static Vibratory Oscillatory Combination Rollers Double drum
3 Wheeled
Pneumatic Tire
Vibratory
Oscillatory
Combination Rollers

11. Static Rollers Variables Weight, speed, rolling pattern
When? OG, Porous, SMA, 4.75mm*

12. Vibratory Rollers
Variables
Amplitude
Frequency
Speed (impact spacing)

13. Amplitude

14. Frequency
Impact Spacing
Check owners manual.

15. Frequency
Correct impact spacing

16. Roller Speed Paver = Plant = Trucking # of Passes of breakdown roller
Frequency setting
Tender Zone?
Roller width/paving width

17. Paver/Roller Speed Do not out run your rollers. 3.5 mph roller
300ft/min – 3 wide to cover X 4 passes
300/12=25ft/min
85% rolling = 21 ft/min paver speed
(140tph)
300ft/min – 2 wide to cover X 4 passes
300/8=37.5
85% rolling = 32 ft/min paver speed
(211tph)

18. Rolling
Turn towards the shoulder(away from traffic) stopping at an angle.
Make sure vibration is turned off before stopping.
Be sure not to turn wheel while stopped.
Break down when asphalt is at its hottest.
Cover entire mat with one pass before starting 2nd.

19. Rolling cont. Take previous stop marks out with next pass.
As paver moved forward, roll up to paver with each pass to seal in heat.
Roll handwork as soon as possible.
Proper longitudinal joint construction.
Stay on hot mat
Know when to “pinch the joint”
Cross-roll transverse joints.

20. Porous/OG
Static only
Strength through design with aggregate structure and modified AC
Vibration can cause over compaction

21. Stone Matrix Asphalt Static roll only Roll as hot as possible
Typically no tender zone
Roll until cool – little concern of over-rolling

22. Warm Mix Easier to compact Higher densities reported
Open to traffic sooner
Use same good rolling procedures as HMA

23. Summary Good design Proper production Proper paving practices
Good rolling techniques
Stay watchful – things change…

24. Thanks
Questions?