1. Got Density? Asphalt Pavement Assn. of Indiana Winter Conference December 2010

2. Why measure density? Surrogate for other properties –Strength –Durability –Permeability Easy and fast

3. Rutting vs. Air Voids Ref: WesTrack

4. Rutting vs. Air Voids Ref: Mn/ROAD 1/2” Rutting in One Year

5. Fatigue vs. Air Voids Ref: WesTrack

6. Permeability

8. Retained Penetration vs Air Voids Ref: NCAT Text Book

9. Pavement Life vs. Air Voids

10. Getting Density Lift Thickness Temperature Compaction Support Equipment

11. NCHRP Report 531 Relationships of HMA In-Place Air Voids, Lift Thickness, and Permeability (NCHRP 9- 27)Relationships of HMA In-Place Air Voids, Lift Thickness, and Permeability (NCHRP 9- 27) Recommended minimum lift thicknesses: –3 X NMAS for fine-graded mixes –4 X NMAS for coarse-graded mixes Thin lifts cool faster –less time available for compaction

12. MultiCool FREE Software for Computing Compaction Window –Base Temp –Weather Conditions –Lift Thickness –Mix Temp –Latitude Available at www.hotmix.org

13. MultiCool

14. Temperature 80 O F Surface & Air Temperature, 5 mph wind

15. 50 O F Surface & Air Temperature, 5 mph wind Temperature

16. 30 O F Surface, 40 O F Air Temperature, 15 mph wind Temperature

17. Compaction Support Weak!!! Weak Support Leads to Poor Compaction!

18. Compaction Support Strong!!! Strong Support Helps Compaction!

19. Balancing Production Balance of plant production, trucking, paver speed and rollers Slow and steady wins the race –Speeding up to get rid of trucks not recommended. Hurts ride Non-uniform compaction

20. Joint Density Controlling segregation important Proper joint construction important Sealers Echelon paving Joint density specification

21. Longitudinal Butt Joint

22. Notched Wedge Joint 12” 1” minimum Max Agg. Size

23. Notched Wedge Joint Attachment

24. Joint Rolling - Unconfined Edge First Pass - Steel Wheel Rollers Inside of edge ~ 6” Second Pass - Steel Wheel Rollers Overhang edge 3-6”

25. 3” - 6” off joint 3” - 6” on joint Longitudinal Joint Hot Mat Cold Mat

26. Longitudinal Joint 1/2 - 3/4 “ overlap

27. Longitudinal Joint Unrolled Rolled

28. Minimizing Joint Problems Minimize Joints Pave in Tandem! May Require More Lane Closures But, It Minimizes Return Trips!

29. Final Quiz Q - What is the maximum number of rollers needed on a paving project? A - Whatever it takes to get density. 2 3 4 1 5 6

30. The Future is Bright! Better Tools to Help Us! Oscillatory Compaction Intelligent Compaction –GPS Location –Mat Stiffness

31. Don’t Forget Quality Diamond Achievement Commendation Diamond Quality Commendation Diamond Paving Commendation