1. Asphalt Rubber Chip Seals
RMWPPP 2018
Portland OR

2. What are Field Blended Binders?
A blend of any combination of PG Asphalt, Crumb Rubber Modifier, Polymer, and other modifiers.
Components blended with mobile equipment in the field or at remote location prior to application on the roadway.
Field blend binders can be custom designed to meet climatic, traffic loading, and other unique field conditions.

3. Why do we modify asphalt?
Unmodified asphalt can be sensitive to temperature variations or adverse conditions such as vehicle loading.
Brittle in the Cold resulting in thermal cracking.
Soft in the Heat resulting in rutting, flushing, and surface deformation at elevated temperatures.
Also doesn’t hurt that we can use recycled tires to modify asphalt and increase performance! Asphalt Rubber can use up to 600 recycled tires per lane mile at a 12” width!!

4. Why Put Rubber In Asphalt?
The purpose is not to get rid of tires but to enhance the performance of the binder.
Tires have great engineering properties, they don’t crack in the cold or melt in the heat. They have a wider range of performance temperatures than asphalt.
Make asphalt pavements that perform like tires.

5. Why Put Rubber In Asphalt?
Tire rubber is an engineering tool used to:
Manage Alligator and Block Cracking
Reduce flushing and raveling.
An aid to increase performance life
Save Money and resources in reduced prep work such as dig outs and crackfill.

6. Where does the Crumb Rubber come from?

7. Multi Stage grinding continues to create ground/graded rubber
First Tires are Collected and Shredded into 2” chips
Multi Stage grinding continues to create ground/graded rubber

8. Rubber and fabric is removed and bagged for delivery

9. Rubber Gradation

10. Type 2 Binder Design

11. Type 2 Binder Properties

12. Type 4 Binder
89% PG 64-28
10% Crumb Rubber Modifier
2% Polymer

13. Asphalt Rubber Blend Site
Finish Tank Reaction Vessel
PG Asphalt Tank
Rubber/Polymer Hoppers

14. Rubber Hopper
Load cells monitor the volume by weight of ground rubber.

15. The ground rubber is carried to the mixing container.

16. PG Asphalt Temperature is elevated in the heat exchanger

17. Bitumen volume is monitored by flow meter.

18. Reaction Vessel
Heated and Agitated

19. The field blend system fully saturates the rubber in the asphalt so that they are stabilized or reach equilibrium

20. Binder Comparison
Type 2 AR Binder
PG Asphalt

21. On Site QC through Viscosity Testing

22. Which binder do I choose Type 2 or Type 4??

23. If your roads need it…..

24. Binder Selection
Type 2 Asphalt Rubber
Type 4 Modified Binder

25. Type 2 Asphalt Rubber Application
.55 to .70 gallons per yd2
Application Temperature of 375 to 410 degrees Fahrenheit.
18-20% recycled tires.

27. Type 4 Asphalt Rubber .35-.50 gallons per yd2
Application Temperature of Fahrenheit
8-10% recycled tires 1-3% polymer

29. How are they applied?
Utilizing equipment equipped with agitation, heating, and CRC (computerized rate control).
Applied at elevated temperatures of 350f plus.
Applied at higher application rates/asphalt residual than most binders.
No water in the system.
Used on a variety of roads from residential, highways, to arterials.

31. Weather?
Field Blend Binders can be applied when rain is in the forecast
Extended Season
Pavement and Ambient temps 55f and rising to begin application
Quick Cure time due to no water in system

32. Wet Pavement Prior to Application

33. Aggregate Application

34. Agg Gradations
3/8 smooth
3/8 course

35. Hot Coated Chips Supplied from HMA plant
.5% to .75% of any grade of PG asphalt coating
225 to 325 degrees Fahrenheit (if required)
Can utilize silo
DO NOT ALLOW BAG HOUSE FINES TO BE INTRODUCED

36. Hot Applied Aggregate Application
24 lb yd² - 35 lb yd²

37. Got Loose Rock?

38. Chip Retention Test Results

39. Compaction Immediately after Application
Compaction needs to start within 90 seconds of application of material

40. Sweeping Performed within 30 minutes of Compaction of Material
Excess material around 10%
Second day sweep recommended
Should always pre-sweep prior to application
Mechanical brooms required for post sweep

41. Benefits to field blends
No “cobwebbing”
Multiple suppliers
On site quality control
Small batches
Low temperature performance
Reduced raveling

42. Who is using them locally?
Chelan County
Clark County
Kitsap County
Pierce County
City of Vancouver
City of Gresham
City of Olympia
City of West Richland
City of La Center
City of Tacoma
City of Madras
Oregon City
City of Tigard
City of Camas
City of Moscow
City of Richland
Hanford

43. Beaver Hill Road
Taken after striping (1 day after application) 10-12% grade

44. 5 years performance Pierce Co.

45. Vancouver Cape Placed in 2012

46. Gresham Asphalt Rubber after 3 years

47. West Richland
Nominated for the IACC Outstanding Achievement in Infrastructure Award.
121,000yd2 of Type 4 binder with fog seal on arterial roads
Contact Drew Woodruff

49. Cape Seal Finish?

52. QUESTIONS?