Design of Rigid Overlays for Airfield Pavements Raymond Sydney Rollings, Jr., Doctor of Philosop

339 Pages·2016·7.71 MB·English

ABSTRACT
Title of Dissertation: Design of Rigid Overlays for Airfield
Pavements
Raymond Sydney Rollings, Jr., Doctor of Philosophy, 1987
Dissertation directed by: Matthew W. Witczak, Professor, Civil
Engineering
Existing rigid overlay pavement design methods are empirical and
use a specified level of cracking as the defined failure condition. The
existing empirical designs are based on tests run thirty years ago, and
current analytical models provide greatly improved abilities to examine
the overlay pavement structure. Emphasis by many agencies on life cycle
cost analysis and more sophisticated maintenance and rehabilitation
strategies require methods of predicting pavement performance rather
than simply developing safe designs. A layered elastic analytical model
was selected to evaluate stresses from applied loads in the pavement
structure. Pavement performance was measured in terms of a Structural
Condition Index which related the type, degree, and severity of pavement
cracking and spalling on a scale of 0 to 100. Models were developed to
represent the effect of cracking in base slabs under the overlay, to
account for fatigue damage of previous traffic on the base pavement, and
to account for the effects of substandard load transfer at slab joints.
The predicted performance of overlays and pavements using this analysis
was checked against the results of full-scale accelerated traffic tests
conducted by the Corps of Engineers and against current overlay design
methods and was found to provide reasonable agreement. This methodology
using the layered elastic analytical model and analysis of fatigue and
cracking in the base slab provides a method of predicting pavement and
overlay deterioration in terms of a Structural Condition Index.
DESIGN OF RIGID OVERLAYS FOR AIRFIELD PAVEMENTS
by
...
Raymond Sydney Rollings, Jr .
Dissertation Submitted to the Faculty of the Graduate School
of the University of Maryland in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy
1987
vo [. \
C • I
Advisory Committee:
Professor M. Witczak
Professor C. Schwartz
Professor M. Aggour
Professor D. Vanney
Professor D. Barker
PREFACE
This study was conducted by Raymond S. Rollings, Jr., U.S. Army
Engineer Waterways Experiment Station· (WES), under the direction of Pro
fessor Matthew W. Witczak, University of Maryland. Funding for this
project was provided by the Federal Aviation Administration under Inter
Agency Agreement No. DTFAOl-81-Y-10523 "Update Overlay Thickness
Criteria" with the WES.
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DEDICATION
This is dedicated to my parents for their support and
encouragement.
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ACKNOWLEDGEMENT
The assistance of Mr. E. J. Alford, Mr. P. S. McCaffrey, Jr. and·
Mr. D. D. Mathews of the Engineering Investigations, Testing, and Vali
dation Group, Pavement Systems Division (PSD), Waterways Experiment Sta
tion (WES), in conducting the slab tests described in Part V of the
report is gratefully acknowledged. Mr. D. Pittman of the Engineering
Analysis Group, PSD, performed the computer stress calculations in
Table C2 that were used for the layered elastic and Westergaard stress
comparisons. Ms. Shirley Heath, formerly of the Engineering Analysis
Group, PSD, and presently with Explosive Effects Division, Structures
Laboratory, WES, performed the joint deflection to load transfer con
versions described in Part VI. Mr. Starr Kohn, formerly with the Engi
neering Investigation, Testing and Validation Group, PSD, presently with
Soils and Materials Engineering, Inc., performed the stress analysis for
Lockbourne test sections R through T in Appendix A. The assistance and
contributions of all of these individuals to this report are greatly
appreciated. The assistance of Ms. Sammie Haney and Ms. Rhonda
Herrington of the PSD in numerous administrative tasks associated with
the preparation of this report is gratefully acknowledged, Drafting by
the WES Engineering, Graphics, and Cartographic Section and typing by
Systems Research and Development Corporation is also gratefully
acknowledged.
The encouragement and advice of numerous colleagues, particularly
Dr. Walter Barker, Ms. Marian Poindexter, and Ms. Phyllis Davis, were of
great assistance.
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The encouragement, assistance, and critical review by Profes
sor M. W. Witczak in particular were invaluable in carrying out and
completing this study.
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TABLE OF CONTENTS
Page
PART I: INTRODUCTION 1
PART II: BACKGROUND • • 4
Current Airfield Rigid Pavement Design 4
Current Rigid Overlay Design Methods 26
PART III: BASIS FOR IMPROVED OVERLAY DESIGN PROCEDURE 40
Performance Criteria 40
Analytical Model 48
Previous Traffic Damage • 56
Methodology 58
PART IV: PERFORMANCE MODEL FOR RIGID PAVEMENTS 60
Test Section Data .•. 60
Test Section Performance 69
Model Evaluation 80
Summary • . . . • . • . 92
PART V: EFFECTIVE MODULUS FOR CRACKED SLABS 94
Existing Models 95
Slab Tests 102
Cracked Slab Model 125
PART VI: LOAD TRANSFER 129
Measured Load Transfer 129
Modifications for Layered Elastic Theory 135
PART VII: PROPOSED DESIGN PROCEDURE 140
Methodology • . • . . 140
Example Calculations 155
Summary • • • . • 167
PART VIII: ANALYSIS OF CORPS OF ENGINEERS OVERLAY TEST DATA 170
Test Section Data 170
Unbonded Overlays 173
Partially Bonded Overlays 190
Fully Bonded Overlays • . 195
Overlays Without Load Transfer 196
PART IX: EVALUATION AND COMPARISON OF OVERLAY DESIGN
PROCEDURES 200
Design Methods 200
Evaluation 202
Comparisons . . 220
Effect of Previous Traffic 225
PART X: CONCLUSIONS AND RECOMMENDATIONS 232
Conclusions . . . . . . . . . • 232
Recommendations for Future Research . 234
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TABLE OF CONTENTS (Continued)
APPENDIX A: CORPS OF ENGINEERS RIGID PAVEMENT
. . . . . . .
TEST SECTION DATA 236
. . . . . . . . .
APPENDIX B: SLAB TEST DATA • 253
APPENDIX C: WESTERGAARD AND LAYERED ELASTIC STRESS
. . . . . . .
CALCULATIONS 289
APPENDIX D: CORPS OF ENGINEERS RIGID OVERLAY TEST
.
SECTION DATA • 297
. . . . . . . .
REFERENCES 313
. . . .
BIBLIOGRAPHY 319
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LIST OF TABLES
No. Page
1 Reduction in Pavement Thickness for High-Strength
Foundations . . • . • . 25
2 Condition Factor Values • 27
3 Descriptive Rating of the PCI • 42
4 PCI Distress Types 43
5 PCI Rigid Pavement Distress Types Used with the SCI 47
6 Example SCI Values Meeting the Corps of Engineers Initial
Failure Definition • . • . • . • . • • • • . • 49
7 Available Rigid Pavement Field Test Data . . . . 61
8 Example SCI Calculation for Keyed Longitudinal Joint
Test Section Item 2-C5 • . . . • . • • • • • 67
9 c and CE Values for Test Sections . • . • • • • . 75
0
10 Predictea Performance of Unfailed Test Items ••. 87
11 Failed Pavements at U-Tapao Airfield • • . • 89
12 Sample Calculations for Determining SCI and E-Ratio
from Nominal Slab Fragment Size •.. 100
13 Predicted Initial Modulus Values Before Cracking 112
14 Summary of SCI Calculations for Test Slabs . . . 119
15 Predicted Modulus Values from Slab 1 by Matching
Deflection Basins . • • . • • . . • • • • • • • • 121
16 Effective Concrete Modulus Using Center Deflections 126
17· Load Transfer for Different Joint Types 133
18 Typical Modulus of Elasticity Values 144
19 Base Slab Stresses and Performance Factors 159
20 Stress and Performance Factors for Overlay 163
21 Example Overlay Damage Calculation Test Section A 2.7-60. 165
22 Summary of the Corps of Engineers Overlay Tests 171
23 Comparison of Predicted and Observed Performance
of Unhanded Overlay Test Items • • • . • . • • . 184
24 Effect of Including Base Slab Cracking on Prediction
of Overlay Deterioration • . • • • • . • 185
25 Performance of Test Items with Substandard
Load Transfer . . • . • • • . . • • • 198
26 Comparison of Overlay Design Methods 201
27 Design Parameters for the Overlay • • • • 204
28 Design Parameters for the Base Pavement 206
29 Aircraft Characteristics . • . • 207
30 Distribution of Design Parameters 208
31 Unhanded Overlay Results . • .. 213
32 Partially Bonded Overlay Results 217
33 Comparison Between Unhanded and Partially
Bonded Overlay Designs . • . . • • • • 218
34 Comparison of Overlay Design Procedure Results , • , • 222
A1 Material Properties for Lockbourne No, 1 Test Sections 237
A2 Performance of Lockbourne No. 1 Test Sections ... , 239
A3 Material Properties for Lockbourne No. 2 Test Section and
Modification • • • . • , . . . . . . . . • 243
A4 Performance for Lockbourne No. 2 Test Section and
Modification 244
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