INVESTIGATION OF THE USE OF OPEN-GRADED FRICTION COURSES IN WISCONSIN

1. INVESTIGATION OF THE USE OF OPEN-GRADED FRICTION COURSES IN WISCONSIN by Richard E. Root, P.E. Root Pavement Technology, Inc.

2. Contract Tasks Task 1 Literature Review Task 2 Cost Analysis Task 3 General Review of Wisconsin Accident Data Task 4 Develop Recommended Procedures for OGFC Construction Task 5 Final Report

3. Contract Task 4 Develop Recommended Procedures for OGFC Construction Mixture Design Construction Practices Acceptance Draft Specifications

4. Change in Scope – 11/15/06 Following the completion of Task 1, a preliminary report will be prepared on the possible use of OGFC mixtures in Wisconsin. Work on the project will be temporarily halted at this point. The preliminary report will be reviewed by the TOC and a decision will be made on the future direction of the WHRP project. The following three options will be considered:

5. Change in Scope – 11/15/06 1. If the literature review looks promising and the TOC supports that position, work will continue on the project according to this proposal.

6. Change in Scope – 11/15/06 2. If the literature review indicates that the use of OGFC in cold weather is not a good idea and the TOC concurs, the project will be halted.

7. Change in Scope – 11/15/06 3. If the literature review indicates that the use of OGFC in cold weather is not a good idea and the TOC concurs, consideration will be given to adjust the research proposal to look at the use of a modified SMA mixture to provide some of the benefits of OGFC with out the problems.

8. Results of Part 1

9. Use of OGFC in Cold States Study Area

10. Winter Maintenance • Freeze early and last to thaw • Difficult to remove snow and ice • Surface subject to snow plow damage • May need special deicing chemicals • Require more treatments • Cold weather and plows may accelerate raveling • Possible issue on bridge decks • Problems with transitions to normal surface

11. Service Life

12. Service Life

13. Functional Life May be extended by cleaning the pores.

14. OGFC Mixture Cost

15. OGFC Mixture Cost • Approximate 15 percent increase in yield • Most agencies give it no credit in the pavement structure • May require special pavement marking • Requires more marking material • Limited construction season

16. Alternate Mixtures Fine Graded HMA Coarse Graded HMA SMA

17. Factors to Consider • Safety and the Law? • Requires best practices on all projects • Where to use? • High traffic to aid in cleaning mixture and justify added cost • Areas with high frequency of wet weather accidents • Balance against possible increase winter accidents • Should not be used on short segments or bridge decks

18. Factors to Consider • Construction issues? • Requires paving at higher ambient temperature • High traffic areas may require night work • Service Life? • Expect a substantial reduction in life compared to standard mixtures and/or SMA • Functional life significantly less than service life • Requires more construction and could result in more construction related accidents • Failure can be quite rapid at end of service life (worst case weeks)

19. Factors to Consider • Costs? • Mixture 50 to 80 percent more than standard mix • Functional life less than half standard mix • Higher construction costs – markings • Higher winter maintenance costs • Repairs? • Not ease to repair damage section of mix without losing drainage capabilities

20. Where are We? • Part 1 • Draft report submitted to TOC • Waiting for responses from three states on current usage of OGFC • Reviewing references for added information for report • TOC review Part 1 report and provide guidance on the need for Part 2

21. What would you get inPart 2? • Information is already available • The recommendations would be presented in a table format • Responses from three of four key sources along with recommendation • Example

22. Part 2 (example)

23. Thanks