Asphalt Rubber Blending
•Download as PPT, PDF•
1 like•1,368 views
Presentation delivered by Jack Van Kirk at the CalAPA 2015 Fall Asphalt Pavement Conference Oct. 28-29 in Sacramento, CA.
Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Similar to Asphalt Rubber Blending
Similar to Asphalt Rubber Blending (20)
More from California Asphalt Pavement Association
More from California Asphalt Pavement Association (20)
Recently uploaded
Recently uploaded (20)
Asphalt Rubber Blending
- 1. Asphalt Rubber Blending By Jack Van Kirk Director of Asphalt Technology George Reed Inc. CalAPA Fall Conference October 28 - 29, 20015 Sacramento, CA
- 2. Asphalt Rubber Binder • How do you produce it? • Quality control? • Binder components? • How do you design it? • How do you test it? • Critical factors?
- 3. Asphalt Rubber Binder • Uses a minimum of 20 +/- 2 % crumb rubber • Uses 10 mesh (2mm) crumb rubber • Reacts/interacts crumb rubber for a minimum of 45 min. at elevated temperatures • Modifies original properties of asphalt cement
- 5. How is Asphalt Rubber Produced? • Specialized equipment and binder blended on-site • High shear blender for mixing crumb rubber with asphalt • Reaction tank with adequate agitation to assure proper reaction • All materials are metered-in
- 6. Asphalt Rubber Blending Schematic Crumb Rubber Asphalt Storage Tank Heat Tank High Speed Blender Reaction VesselBinder Pumped to Plant
- 10. Reaction Vessel Reaction Vessel Augers and Direct Fire Heating
- 12. Computer Controlled Metering MPQP Requirements
- 13. High Shear Blender Computer Controlled Key is to have proper blending of components
- 14. Chip Seal Plant Site Set-up
- 15. Quality Control • Materials sampling and testing • Field binder testing - hand held viscometer
- 16. Materials Sampling • Components of the binder must be sampled and tested • Asphalt rubber binder must be sampled from a point that will provide a representative sample
- 18. Quality Control/Quality Assurance • QC- testing performed by contractor to ensure production is in control • QA- testing performed to accept/reject the product
- 19. On-Site Qc for Asphalt Rubber Binder
- 20. Components of the Asphalt Rubber Binder • Crumb rubber modifier (CRM) • Asphalt cement • Asphalt modifier
- 21. Paving Asphalt • PG 64-16 and PG 58-22 asphalt (80 +/- 2 %) (hot environments PG 70-10) • Conform to Section 92 “Asphalts” of the Standard Specifications
- 22. Crumb Rubber Modifier (CRM) • Scrap tire CRM (18 – 22 %) • Max. 0.01 % wire (by wt. Of CRM) • Max. 0.05 % fabric (by wt. Of CRM) • It must be a very clean rubber
- 23. Crumb Rubber
- 25. Laboratory Binder Design • Asphalt heated to 400 to 425°F • Asphalt modifier added to asphalt • Crumb rubber blended into asphalt/asphalt modifier blend • Reacted for a minimum of 45 minutes • Agitated (stirred) frequently during reaction period • Properties tested over 24 hour period Compatibility of components
- 26. Binder Profile Test 45 Minute s 60 Minute s 90 Minutes 120 Minutes 240 Minutes 360 Minutes 1440 Minutes Viscosity @ 375°F 3600 3450 3100 2800 2200 2000 1800 Cone Penetrati on @ 77°F 30 34 32 Resilience , % Rebound @ 77°F 51 56 51 Softening 166 165 163.5
- 27. Minimum reaction point Typical Reaction Curve
- 28. Asphalt Rubber Binder Properties • Cone penetration • Resilience • Field softening point • Viscosity
- 29. Cone Penetration
- 30. Resilience
- 31. Softening Point • Disc of asphalt material is prepared • Ball bearing placed on top • Placed in water or glycol • Water heated up at a slow constant rate • Softening point is temperature at which ball falls through
- 32. Hand Held Viscometer • Haake/Rion viscometer or equivalent • Viscometer must be calibrated • Viscosity range 1500 - 4000 cp @ 375°F • Target viscosity: hot mix binder is about 2500 - 3500 cp, chip seal binder 1800 – 2200cp • Viscosity is a very good indicator of other binder properties
- 34. Critical Factors Affecting Asphalt Rubber Binder • Grade and source of base asphalt • Amount of crumb rubber • Gradation of crumb rubber • Reaction time and temperature
- 36. Rubber particles in the binder help fight cracking
- 38. Current Use Asphalt Rubber Strategies • Asphalt Rubber Hot Mix (Gap graded and open graded) • Asphalt Rubber Chip Seal • Asphalt Rubber Cape Seal • Multi-Layer Systems
- 39. Properly blended binder Good performing pavement strategy Results in
- 40. Thank You