32 nd Annual Airport Conference Hershey, Pennsylvania March 4, 2009 David Peshkin, P.E.

1. Managing Airfield PCC Pavements With Materials-Related Distress 32nd Annual Airport Conference Hershey, Pennsylvania March 4, 2009 David Peshkin, P.E. providing engineering solutions to improve pavement performance

2. Presentation Overview • Current practices in PCC pavement evaluation • Observations and Issues • Needs • New developments

3. Current Practices • Guidelines and Procedures for Maintenance of Airfield Pavements, FAA AC 150/5380-6B, Chapter 3: Pavement Distress • Airport Pavement Condition Index Surveys, ASTM 5340-04 • Others (PASER: 5320-17; ASR: 5380-8)

4. FAA AC 5380-6B Cracking: caused by stresses, overloading, loss of subgrade support, and insufficient and/or improperly cut joints. • Durability “D” Cracking • Shrinkage Cracking

5. FAA A/C 5380-6B (continued) Disintegration: caused by improper curing and finishing, unsuitable aggregates, and improper mixing • Scaling, Map Cracking, and Crazing • Joint Spalling • Corner Spalling • Shattered Slab/Intersection Cracks • Blowups • Popouts • Patching

6. ASTM D 5340 Airport Pavement Condition Index Surveys • 15 distress types • Description, severity levels (L, M, H), how to count • Deduct curves • Causes discussed in “Description”

7. ASTM D 5340: Distress Causes • D cracking: concrete’s inability to withstand environmental factors • Popouts: freeze-thaw action in combination with expansive aggregates • Scaling, map cracking, and crazing: last two caused by overfinishing; scaling caused by deicing salts, improper construction, freeze-thaw cycles, poor aggregate. Also cement-aggregate interaction

8. ASTM D 5340: Distress Causes (continued) • Shrinkage: formed during setting and curing • Spalling: incompressibles, loadings, and overworking

9. Observations and Issues • PCI procedure effective tool in managing pavements • Used for both network- and project-level efforts • Additional insights from considering distress causes

10. Observations and Issues (continued) • Identification procedures combine descriptions and causes • Some distresses not well described • Procedure not particularly sensitive to the progressive deterioration of PCC with materials-related distress (MRD) • This has left airports with high PCIs and imminent need for major work

11. Needs • Identification of MRD in the field • Prediction of progression of MRD • Understanding of the risk associated with MRD

12. New Developments • Additional guidance from FAA (ASR Identification Handbook) • Modifications to the PCI procedure • Innovative Pavement Research Foundation (IPRF) projects, and specifically: IPRF Project 06-06 on MRD and Projected Pavement Life

13. MRD Inspection and Rating Procedure Supplement to the PCI Applied if signs of MRD observed Inspection procedure results in the calculation of a MRD rating (MRDR)

14. Inspection Procedure Development Developed MRD handbook Performed airport inspection Used inspection, interviews with maintenance/ engineering staff to refine inspection procedure and identify distress progression sequences

15. Inspection Procedure Development (continued) • Refined survey procedure applied at second airport • Detailed survey administered • Fourteen respondents to survey • Used to establish distress progression sequences • Follow-up visits planned • Further refinements • Progression

16. MRD Manifestations • Interior Locations • A. Pattern Cracking (L, M) • B. Scaling (N/A) • C. Popouts (L, M, H) • D. Surface Honeycombing (L, M, H) • Joints and Corners • E. Sliver Spalling (N/A) • F. Perpendicular Cracking (L, M) • G. Parallel Cracking (L, M) • H. Joint Disintegration (N/A) • Overall • I. Staining (N/A) • J. Patching (L, M, H) • K. Expansion (Y/N)

17. A. Pattern Cracking (L, M)

18. B. Scaling (N/A)

19. D. Popouts (L, M, H)

20. D. Surface Honeycombing (L, M, H)

21. E. Sliver Spalling (N/A)

22. F. Perpendicular Cracking (L, M)

23. G. Parallel Cracking (L, M)

24. Both F & G

25. H. Joint Disintegration (N/A)

26. I. Staining (N/A)

27. J. Patching (L, M, H)

28. G. Misalignment/Expansion

29. Rating Procedure Development Severity of distress Projected timing and type of future distress

30. Distress Progression (Interior)

31. Distress Progression (Joint and Corner)

32. Distress Progression (Overall)

33. Distress Progression Sequences • Corner deterioration A/P 1A/P 2 • Staining to low severity cracking: 4.9 yr 3.5 yr • Low to medium severity cracking: 4.0 yr 2.6 yr • Medium to joint deterioration: 3.1 yr 2.5 yr • Staining to repair: 12 yr 8.6 yr • Joint Deterioration • Staining to low severity cracking: 2.0 yr 4.0 yr • Low to medium severity cracking: 2.0 yr 3.0 yr • Medium to joint deterioration: 2.1 yr 2.6 yr • Staining to repair: 6.1 yr 9.6 yr

34. Observations • Interior distresses not as critical as corner and joint distresses • Staining is a precursor to cracking which leads to FOD • Locally, different factors will affect development and progression of distresses

35. Current Status of Rating • MRD data has been used to generate a single composite MRD Rating (MRDR) • No MRD, the rating is zero • Maximum is yet undefined • Currently headed toward 2000 • Based on the MRDR, thresholds will be set where M&R decisions must be made • These need to be set

36. Future Work Reinspections to better understand rate of progression Finalize inspection procedures Complete distress progression sequencing Finalize weighting scheme for determination of the MRDR Prepare and submit final report next fall

37. Typical PCI Traditional Action Decision Point Level of Unacceptable Risk Projected Risk Risk Units (To be Determined) MRD Decision Point FOD Potential Curve t1 t2

38. Expected Impact Does not take place of petrographic analysis or other diagnostics! More tools to identify signs of MRD in field Procedure to monitor MRD progression Link between MRDR and risk/action Will supplement PCI where MRDs are identified

39. Thank You! For questions or comments: David Peshkin, P.E. Applied Pavement Technology, Inc. dpeshkin@appliedpavement.com 217.398.3977