1. 2010 FAA Airport Technology Transfer Conference Some Key Findings from NAPTF Testing of Unbonded PCC Overlays IPRF Project 04-02: Improved Overlay Design Parameters for Concrete Airfield Pavements —The Baseline Experiment IPRF Project 06-03: Evaluation of Design Parameters for Rigid Overlays —SCI Validation Study

2. 2010 FAA Airport Technology Transfer Conference Overview

3. 2010 FAA Airport Technology Transfer Conference 6 inch OL 10 inch SL 7.5 inch OL 7.5 inch UL High-strength SubgradeLow-strength Subgrade 9 inch OL 6 inch UL Medium-strength Subgrade Baseline Experiment—2006 (2007) 9 inch OL 6 inch OL 10 inch SL 7.5 inch OL 7.5 inch SL High-strength SubgradeLow-strength Subgrade 6 inch SL Medium-strength Subgrade SCI Validation Study—2007/2008 (2009) Full-Scale Testing at the NAPTF

4. 2010 FAA Airport Technology Transfer Conference Longitudinal and Transverse Cross-Sections NORTHSOUTH 55 12.5 10 12.5

5. 2010 FAA Airport Technology Transfer Conference Date Passes SCI 08/01/062046 92 4 4 6 6 88 10 08/03/062574 80 08/10/062772 73 08/11/063234 68 08/24/063234 63 08/28/063234 57 09/13/063234 46 09/14/063744 39 09/19/064552 31 09/22/065146 24 08/04/062574 73 09/29/065146 19 10/02/065146 16 10/03/065146 14 Triple Dual Tandem 57 in 54 in 50,000 lbs/wheel 230 psi tire pressure Test Item N1 0 -12.5-25 Final Passes OL SCI 5146 14 32 UL SCI 8.6-in PCC OL 6.3-in PCC UL 5.6-in Aggregate Base Subgrade k=135 pci -5-17.5 -30 1 2 3 4 5 6 7 8 9 10 11 12 UL SCI = 100

6. 2010 FAA Airport Technology Transfer Conference 4 4 6 6 88 10 0 12.5 25 Dual Tandem 57 in 54 in 50,000 lbs/wheel 230 psi tire pressure 5 17.5 30 7 8 9 10 11 12 1 2 3 4 5 6 Test Item S1 08/04/063168 93 08/08/063432 85 08/10/064356 76 08/09/063894 78 08/11/064818 67 09/13/065016 54 09/22/068116 46 09/26/06 9370 32 10/02/0611614 16 10/03/0612142 7 09/14/065526 51 09/29/0611020 22 10/31/0612142 7 09/19/068116 50 Date Passes SCI 8.7-in PCC OL 6.3-in PCC UL 5.8-in Aggregate Base Subgrade k=135 pci Final Passes OL SCI 12142 7 39 UL SCI UL SCI = 100

7. 2010 FAA Airport Technology Transfer Conference 12/18/06 Structural Section 1 02/20/07 Transition 1N-7U 1N-8U 1N-9U 1N-10U 1N-11U 1N-12U 1N-1U 1N-2U 1N-3U 1N-4U 1N-5U 1N-6U 1S-7U 1S-8U 1S-9U 1S-10U 1S-11U 1S-12U 1S-1U 1S-2U 1S-3U 1S-4U 1S-5U 1S-6U

8. 2010 FAA Airport Technology Transfer Conference 4 4 6 6 88 10 0 -12.5-25 -5-17.5 -30 1 2 3 4 5 6 7 8 9 10 11 12 Test Item N1 Triple Dual Tandem 57 in 54 in 42.5k lbs/wheel 230 psi tire pressure 9.3-in PCC OL 6.3-in PCC UL 5.6-in Aggregate Base Subgrade k=135 pci 11/14/07 3696 88 11/19/07 4422 83 11/21/07 4950 77 12/03/07 7194 68 12/05/07 7986 55 12/07/07 8712 51 12/10/07 9108 48 12/11/07 9504 42 12/19/07 11286 27 01/11/08 13398 26 01/16/08 14850 24 01/18/08 15510 12 Date Passes SCI Final3 UnderlaySCI Beginning25

9. 2010 FAA Airport Technology Transfer Conference 4 4 6 6 88 10 0 12.5 25 Dual Tandem 57 in 54 in 42.5k lbs/wheel 230 psi tire pressure 5 17.5 30 7 8 9 10 11 12 1 2 3 4 5 6 Test Item S1 9.3-in PCC OL 6.3-in PCC UL 5.8-in Aggregate Base Subgrade k=135 pci 04/02/08 33264 18 Date Passes SCI 01/16/08 14850 80 01/23/08 16316 80 02/01/08 19008 70 02/25/08 20328 58 03/24/08 31350 23 12/13/07 9966 88 03/05/08 24684 52 03/20/08 30096 31 03/21/08 30756 29 03/26/08 32604 20 02/04/08 19602 63 03/11/08 27126 46 UnderlaySCI Beginning23 Final8

10. 2010 FAA Airport Technology Transfer Conference Selected Summary of Goals and Findings Measured Responses Gears Layer Interactions Performance SCI

11. 2010 FAA Airport Technology Transfer Conference A. Refine the relationship between underlying pavement effective modulus and SCI. -5-17.5 -30 1 2 3 4 5 6 7 8 9 10 11 12 SCI was calculated according to ASTM D 5340 “Standard Test Method for Airport Pavement Condition Index Survey.” The SCI value of a test item represents the crack types, crack density and crack severity that are distributed in the 12 slabs within a test item.

12. 2010 FAA Airport Technology Transfer Conference Dr. Rollings’ Model Observation on 6 slabs on subgrade at WES. Cracks were introduced by dropping a headache ball. Initial slab moduli were determined by BISDEF from FWD results. Deteriorated slab moduli were determined by using BISAR to match the deflection under the center of the loaded plate. Subgrade was assigned a constant value = 10000 psi. SCI of slabs were calculated based on assumption that a single type of crack in one slab represents 50% of slabs within a test item having the same specific type of crack.

13. 2010 FAA Airport Technology Transfer Conference Underlay SCI Investigation

14. 2010 FAA Airport Technology Transfer Conference Comparison to Rollings Relationship

15. 2010 FAA Airport Technology Transfer Conference

16. 10 X 10 grid in 12.5 ft X 12.5 ft slab DateCrack Densitytotal crack length, ft# of pieces 8/8/200611/100 = 11%12.52 8/10/200618/100 = 18%19.93 9/22/200621/100 = 21%24.14 9/26/200630/100 = 30%34.76 9/29/200635/100 = 35%489 10/2/200643/100 = 43%58.811 Alternate Indicators of Structural Damage or Crack Density

17. 2010 FAA Airport Technology Transfer Conference Relationship between Underlay E-Ratio and Distress Density Intervals

18. 2010 FAA Airport Technology Transfer Conference Finding: Rollings equation using SCI provides a reasonable fit to BAKFAA moduli from HWD testing for the underlay. Recommendation: Continue use of the Rollings equation, with some modification.

19. 2010 FAA Airport Technology Transfer Conference B. Improve understanding of how underlay condition affects overlay performance, and of the interaction between pavement layers. SCI Initial – Final (Passes) 50,000-lb wheel load 42,500-lb wheel load Test ItemBaseline OLBaseline ULSCI OLSCI UL N1 100 - 14 (5146) 100 - 32 100 - 12 (15,510) 25 - 3 N2 100 - 21 (5146) 100 - 57 100 - 29 (35,260) 43 - 17 N3 100 - 29 (5146) 100 - 87 100 - 27 (35,260) 84 -26 S1 100 - 7 (12,142) 100 - 39 100 - 18 (33,264) 23 - 6 S2 100 - 17 (16,567) 100 - 33 100 - 66 (42,834) 26 - 9 S3 100 - 15 (12,142) 100 - 92100 - 39 (35,250) 81 - 23

20. 2010 FAA Airport Technology Transfer Conference Baseline Experiment

21. 2010 FAA Airport Technology Transfer Conference SCI Validation Study

22. 2010 FAA Airport Technology Transfer Conference Baseline Experiment: Approximate Passes to SCI Values SCI Passes N1 9”/6” S1 9”/6” N2 7.5”/7.5” S2 7.5”/7.5” N3 6”/10” S3 6”/10” 80 245637622456552425743300 60 323450163234937032344580 40 3742874340881214244405524

23. 2010 FAA Airport Technology Transfer Conference SCI Validation Study: Approximate Passes to SCI Values SCI Passes N1 9”/6” S1 9”/6” N2 7.5”/7.5” S2 7.5”/7.5” N3 6”/10” S3 6”/10” 80 50001500010000230001250024000 60 75002000015000>420001600030000 40 100003000021000???2500035000

24. 2010 FAA Airport Technology Transfer Conference Finding: Considering load effects only, unbonded overlays over existing pavements with lower SCI values accumulated more passes to failure than anticipated. Finding: Overlays of equal or less thickness to the existing pavement achieved the best performance, for the same overall total pavement thickness.

25. 2010 FAA Airport Technology Transfer Conference Matched and Mismatched Transverse Joints Examined on the basis of: Overall performance Intact slab life Load transfer efficiency Deflection basin area Although matched and mismatched transverse joints exhibited slightly different mechanical behavior for the unbonded overlay, the passes prior to the first crack or to failure were affected more by other structure parameters such as E*h ratio.

26. 2010 FAA Airport Technology Transfer Conference Intact Slab Life – Number of passes prior to the first crack of a slab normalized to number of passes prior to SCI = 80 of the test item North Test Item (Initial UL SCI)

27. 2010 FAA Airport Technology Transfer Conference Intact Slab Life – Number of passes prior to the first crack of a slab normalized to number of passes prior to SCI = 80 of the test item South Test Item (Initial UL SCI)

28. 2010 FAA Airport Technology Transfer Conference Recommendation: From this experiment, there was no evidence to indicate that joints should not be mismatched if there is a reason to do so. Other factors should govern this decision.

29. 2010 FAA Airport Technology Transfer Conference C. Quantify differences in responses and resulting impacts on failure criteria between dual tandem and triple dual tandem gears. Passes to SCI Levels

30. 2010 FAA Airport Technology Transfer Conference Total Gear Load on North Test Items = 150% of Total Gear Load on South Test Items Baseline SCI Section 1 Pass RatioSection 2 Pass RatioSection 3 Pass Ratio 801.52.31.3 601.63.01.4 402.43.01.3 202.22.71.9 SCI Validation 803.22.41.9 602.73.61.8 402.9--1.3 Ratios of Passes on Test Items (South/North)

31. 2010 FAA Airport Technology Transfer Conference Predicted Ratios from FAARFIELD 1.304 (South/North) Total Gear Load on North Test Items = 150% of Total Gear Load on South Test Items Baseline SCI Section 1 Pass RatioSection 2 Pass RatioSection 3 Pass Ratio 801.91.31.5 601.91.31.5 401.91.31.5 201.91.31.5 SCI Validation 801.61.21.4 601.61.21.3 401.61.21.3

32. 2010 FAA Airport Technology Transfer Conference

33. Strain Recovery % Between Axles Baseline Experiment Pre-Cracking Responses Strain Gage Location N1S1N2S2N3S3 MeanSDMeanSDMeanSDMeanSDMeanSDMeanSD Top of Overlay 70246567417752083139919 Bottom of Overlay 12825101228517137561261825059 Top of Underlay 9518541097316218468306 Bottom of Underlay 124644861623678275912305

34. 2010 FAA Airport Technology Transfer Conference D. Verify whether measured responses match predicted responses from current models and design methods. (Rollings, 1988)

35. 2010 FAA Airport Technology Transfer Conference

36. (Rollings, 1988)

37. 2010 FAA Airport Technology Transfer Conference BASELINE EXPERIMENT FAARFIELD 1.304 ANALYSIS SUMMARY WITH MR = 550 psi TEST ITEMSN1S1N2S2N3S3 STRUCTURAL CROSS-SECTIONS 8.6-in OL 6.3-in UL 5.6-in Agg 8.7-in OL 6.3-in UL 5.8-in Agg 7.4-in OL 7.4-in UL 5.5-in Agg 7.3-in OL 7.7-in UL 5.7-in Agg 5.6-in OL 9.8-in UL 4.7-in Agg 5.7-in OL 9.8-in UL 4.8-in Agg INITIAL UNDERLAY SCI 100 MATERIAL INFORMATION E pcc = 4M psi, MR = 550 psi, k sub = 135 pci, %CDFU = 0% LOADING CONFIGURATION Dual Spacing: 54 in., Tandem Spacing: 57 in. Wheel Load: 50,000 lb., Tire Pressure: 230 psi TripleTwinTripleTwinTripleTwin PREDICTED STRESSES (psi) OVERLAY 688665747724807795 UNDERLAY 402383364362318308

38. 2010 FAA Airport Technology Transfer Conference SCI VALIDATION STUDY FAARFIELD 1.304 ANALYSIS SUMMARY WITH MR = 550 psi TEST ITEMSN1S1N2S2N3S3 STRUCTURAL CROSS-SECTIONS 9.3-in OL 6.3-in UL 5.6-in Agg 9.4-in OL 6.3-in UL 5.8-in Agg 8.2-in OL 7.4-in UL 5.5-in Agg 8.2-in OL 7.7-in UL 5.7-in Agg 6.5-in OL 9.8-in UL 4.7-in Agg 6.5-in OL 9.8-in UL 4.8-in Agg INITIAL UNDERLAY SCI 252343288481 MATERIAL INFORMATION E pcc = 4M psi, MR= 550 psi, k sub = 135 pci, %CDFU= 100% LOADING CONFIGURATION Dual Spacing: 54 in., Tandem Spacing: 57 in. Wheel Load: 42,500 lb., Tire Pressure: 230 psi TripleTwinTripleTwinTripleTwin PREDICTED STRESSES (psi) OVERLAY 626607647670618595 UNDERLAY 7062166105274280

39. 2010 FAA Airport Technology Transfer Conference Baseline Test Item N1

40. 2010 FAA Airport Technology Transfer Conference Baseline Test Item S1

41. 2010 FAA Airport Technology Transfer Conference SCI Validation Test Item N1

42. 2010 FAA Airport Technology Transfer Conference SCI Validation Test Item S1

43. 2010 FAA Airport Technology Transfer Conference Data for Ongoing and Future Analysis

44. 2010 FAA Airport Technology Transfer Conference CUMULATIVE AREA AND PEAK STRAIN FOR ODD-NUMBERED PASSES (WEST TO EAST) FOR EG-O-N1-1B

45. 2010 FAA Airport Technology Transfer Conference CUMULATIVE AREA AND PEAK STRAIN FOR EVEN-NUMBERED PASSES (EAST TO WEST) FOR EG-O-N1-1B

46. 2010 FAA Airport Technology Transfer Conference QES: Co-PI Dennis Morian, Joe Reiter, Suri Sadasivam,..... Penn State: Lin Yeh, Vishal Singh, Hao Yin, Maria Lopez de Murphy Other team members: Tasos Ioannides, Shie Shin Wu, John Rice Acknowledgements Jim Lafrenz Project Panel David Brill, Gordon Hayhoe, Murphy Flynn, Frank Pecht,..... Project Team Members

47. 2010 FAA Airport Technology Transfer Conference THANK YOU QUESTIONS?