1. Univ of Wis - Platteville
Longitudinal Cracking in Jointed Plain Concrete Pavement: Synthesis of Experiences in the Midwest
Robert Schmitt and
Sam Owusu-Ababio,
Univ of Wis - Platteville

2. Outline
Background
Objectives
On-line Survey
Survey Results
Summary

3. Background
Wisconsin DOT initiative in the early 1990s to construct widened concrete pavement, ft.
Limit pavement edge stress and deflection impacts
Reduce shoulder maintenance cost
Minimize exposure of maintenance crew to high volume roadways

4. Background Current problems with widened PCC:
Observing Longitudinal Cracking
Lacking information as to why

5. Objectives Understand causes of longitudinal cracking
Survey six states in Midwest
Input for developing guidelines

6. Guidelines Development Framework
Panel Width Guidelines
ACPA Professionals online discussion on JPCP
Literature Review & Synthesis
In-service Performance of Wisconsin JPCP
Life Cycle Cost Analysis
Survey of Midwest Pavement Professionals

7. On-line Survey
522 county engineers and pavement professionals from Iowa, Minnesota, Wisconsin, Illinois, Ohio, and Michigan
Fall 2011
Questions centered on:
Criteria for determining panel widths on rural hwys
Commonly used panel widths
Frequency of longitudinal cracking occurrence
Probable causes of longitudinal cracking
- Design features, construction practices
such as thickness, tie bars, etc.

8. On-line Survey 37 of 522 engineers responded with information
4-month open period, Aug-Nov 2011
Significant majority did not have PCC pavement in their county
Sample considered unbiased

9. Cross-Section
What are selection criteria & most common panel widths?

10. Criteria for Cross-Section
Other: 3/4 had no concrete pavements under their jurisdictions; 1/4 use state roads "standards"

11. Panel Widths 2-Lane, 2-Way Rural

12. Panel Widths 2-Lane, 2-Way Rural
Other: state standard

13. Criteria by Panel Width, 2-Lane
Criterion Input for Panel Width Selection
Traffic volume
Percent truck traffic
Ease of constr.
Hwy Func. Class
Pavt. Thick.
Constr. & Maint. Cost
12 ft 10 6 5 4
13 ft 1
14 ft
15 ft 2
Other 3

14. Panel Widths 4-Lane, 2-Way Rural

15. Panel Widths 4-Lane, 2-Way Rural
Other: mostly indicated no multi-lane JPCP under their respective jurisdictions.

16. Criteria by Panel Width, 4-Lane
Traffic volume
Percent truck traffic
Ease of constr.
Hwy Func.
Class
Pavt. Thick.
Constr.
& Maint. Cost
12 feet 7 5 2 8 4
13 feet 1
14 feet
15 feet
Other, please specify 3

17. So far….. Panel width selection factors
Pavement thickness. Width-to-Thickness ratio.
Traffic volume
Percent trucks
Ease of construction
Construction and maintenance cost
Most commonly used panel widths
12 ft and 15 ft for 2-lane 2-way rural pavements
12 ft for multi-lane rural pavements

18. Longitudinal Cracking … why?

19. Longitudinal Cracking occurrence
Other: Subgrade issue rather than width; No significant difference between panel widths

20. Longitudinal Cracking by Thickness
Other: Majority specified 6-in thickness having the highest frequency of longitudinal cracking

21. Longitudinal Cracking by Trans. Jt.
Other: 20-ft transverse joint spacing; not sure

22. Longitudinal Cracking by Tie Bars

23. Longitudinal Cracking by Constr. Bars

24. 2-Lane Constr. and Width

25. Multi-Lane Constr. and Width

26. Longitudinal Cracking by Location

27. Topography

28. Longitudinal Cracking by Topo.

29. Topography and Width

30. Premature Long. Crack.
1 month to 5 years

31. Methods for Fixing Long. Crack.
Rout and seal
Cross-stitching
Partial or full panel replacement

32. Cost to Repair Long. Crack.
Low-end crack fill or rout-and-seal
$0.50/lf to $9/lf, avg $1.20/lf
High-end stitch or full-depth
$15/lf to $300/lf, avg $122/lf

33. Summary
37 of 522 county engineers and pavement professionals from Iowa, Minnesota, Wisconsin, Illinois, Ohio, and Michigan
Aug-Nov 2011
Significant majority did not have PCC pavement in their county
Sample considered unbiased

34. Summary Factor Finding Panel Width
12 ft and 15 ft wide panels had higher longitudinal cracking frequencies than 13 ft and 14 ft wide panels.
Pavement Thickness
Thicker pavements (≥ 11 in) less cracking compared to thinner pavements.
Trans. Joint Spacing
More longitudinal cracking tends to occur with shorter joint spacing, 20 ft spacing.
Tie Bars
Split opinion whether there is an effect on longitudinal cracking.
Construction-related Practices
High frequencies with inadequate base compaction and poor joint saw-cut timing. Misaligned dowel bars and faulty vibrators also contributing factors.
Panel Location
More cracking at mid-panel compared to the vicinity of sawn longitudinal joints.
Topography and Structures
Cut/Fills, highway structures (bridges, drainage, culverts) and areas with differential subgrade heaving.

35. More Information wisdotresearch.wi.gov
Longitudinal Cracking on Widened Pavements

36. Thank You
Survey Respondents