CONTENTS PART 1 FUNDAMENTAL PRINCIPLES 1 1 Pavement Types, Wheel Loads, and Design Factors 3 Test Roads in the United States 4 Definition of Pavement Types 5 Highway and Airport Pavements Compared 8 Wheel Loads 11 Tire Pressures, Contact Pressures, and Tire Imprint 12 Design Factors 13 Types of Distress, Structural and Functional 15 Serviceability 17 The Design Process, Design Strategies 18 Systems Analysis 22 Pavement Performance and Theory 22 2 Stresses In Flexible Pavements 24 Layered System Concepts 25 Multilayered Solutions 28 Two-Layer System 40 Three-Layer System 44 Fundamental Design Concepts 72 Summary 76 3 Stresses in Rigid Pavements 81 Curvature and Stresses Caused by Bending 82 Relative Stiffness of Slabs 83 Modulus of Subgrade Reaction 83 Stresses due to Warping 85 Stresses due to Friction 88 Effects of Warping, Contraction, and Expansion 90 Plain versus Reinforced Pavements 92 Definition of Joint Types 94 Stresses in Reinforced Pavements 97 Stresses in Dowel Bars 98 Tie Bars 105 Continuous Reinforcement 106 Prestressed Concrete Pavements 109 Stresses due to Load 110 Influence Charts 118 Stress Values from Design Charts 120 Effect of Tire Pressure, Total Load, and Wheel Configuration 122 Effect of Modulus of Subgrade Reaction on Thickness 122 Combined Stresses 123 Effect of k and h on Warping Stresses J 23 Thickness Design Criteria 124 Consideration of Warping Stresses in Design 125 4 Vehicle and Traffic Consideration 128 Fixed Traffic versus Fixed Vehicle 128 Determining Equivalent Single-Wheel Loads (ESWL) 130 Effect of Variables, Flexible Pavements 131 Procedures, Airport ESWL 133 Flexible Pavements, Equal Stress ESWL 134 Flexible Pavements, Equal Deflection ESWL 136 Flexible Pavements, Two-Layer ESWL 140 Rigid-Pavement ESWL 144 Equivalent Wheel Load Factors 147 General Form of EWLF 153 Effect of Aircraft Wander on Airport Pavement Design 155 Application of Principles on Aircraft Wander 158 Pavement Layout for Variable Traffic 160 Equivalent Axle Loads (EAL) for Highway Design 162 5 Climate, Environment 177 Frost Heave 177 Loss of Strength during Frost Melting 186 Water in Pavements 186 Application of Principles 189 Permafrost 193 6 The Economic Factor, Design Strategies, System Analysis 195 Techniques and Limitations 195 Pavement Costs 196 Economic Analysis 199 Effect of Growth and Variable Costing 203 Estimating Costs 204 Sensitivity of the Cost Factors 209 Illustrative Examples of Computation 212 Optimum Stage Construction 217 Nonsurfaced Roads versus Paved Surfaces 217 Summary, Economic Analysis 219 PART 2 PROPERTIES OF PAVEMENT COMPONENTS; MATERIALS CHARACTERIZATION 221 7 Soil Classification 223 Definition of Soil and Soil Components 223 Soil Horizons 224 Parent Materials and Their Influence on Design 225 Moisture-Solid Relationships 228 Soil Classification 229 AASHO Soil Classification 231 Federal Aviation Administration Classification 234 Unified Soil Classification 235 Pedological Soil Classification 238 Application,of Soil Classification 240 8 Materials Characterization 243 Catagorization of Test Types 243 Plate-loading Tests 244 Triaxial Compression Test 249 California Bearing Ratio Test 251 Stabilometer and Cohesiometer 256 Tests for Bituminous Mixtures 257 Modulus of Rupture 258 Indirect Tensile Test 259 Layered I^iput Parameter Tests 261 Resilient/Modulus Test 262 Complete (Dynamic) Modulus Test 265 Dynamic (Repeated Flexural) Stiffness 267 Diametral Resilient Modulus 268 Asphalt Mix Stiffness (Shell Nomograph) 269 Creep Test 272 Wave Propagation Techniques 272 CBR-Modulus Correlation 276 Typical Modulus Values 277 Poisson's Ratio 280 Fatigue Testing 282 Permanent Deformation 289 9 Soil and Base Stabilization 300 Reasons for Using Admixture Stabilization 300 Mechanics of Stabilization 301 Cement Stabilization 304 Evaluation and Criteria for Suitability, Cement Stabilization 309 Construction and Field Control 310 Soil-Lime 312 Evaluation and Criteria for Suitability, Lime Stabilization 315 Construction and Field Control 316 Soil-Bitumen 316 Evaluation and Criteria for Suitability, Bituminous Stabilization 319 Construction and Field Control 320 Dilute Emulsion Stabilization 321 Membranes 321 Stabilization with Calcium Chloride and Sodium Chloride 321 Summary of Principles 321 10 Subgrades 325 Compaction 325 Strength-Density-Moisture Considerations 325 Choosing Compacting Moisture Content, Density, and Depth of Compaction 328 Design Units for Subgrade Design 328 Design Units and Selection of Design Values 330 Sampling Requirements and Selection of Design Value 334 Estimating Final Moisture Content 339 Estimation of California Bearing Ratio 340 Special Provisions and Problems 340 Compaction Control 345 Summary of Principles Involved in Subgrade Design 352 11 Bases and Subbases 356 Purpose of Base Course 356 General Properties of Soil-Aggregate Mixtures 357 Typical Grading Requirements, Nonstabilized Bases 365 Macadam Base Courses 367 Cement-treated Bases 368 Asphalt-treated Bases 368 Equivalency Coefficients 369 Base and Subbase Drainage 370 Bases for Concrete Pavements 371 Bases and Subbases for Flexible Pavements 374 Untreated Surfaces 375 Construction 377 Field Control 378 Summary 380 12 Bituminous Surface 384 Function of the Surface 384 Types of Bituminous Materials 385 Pavement Types 386 Skid Qualities 387 Jet-resistant Pavements 390 Low-Temperature Cracking 391 Asphalt Concrete Mix Design 398 Thickness Requirements 403 13 Material Variability 405 Fundamental Statistical Concepts 405 The Normal Distribution 407 The Distribution 411 Measured Variability of Pavement Systems 413 Soil Area Variability 417 Pavement Layer Variability 418 Pavement Section Variability 428 Statistical Applications in Pavement Analysis 428 Design and Evaluation 433 Quality Assurance 439 Summary 442 PART 3 DESIGN OF FLEXIBLE PAVEMENTS 445 14 Design of Flexible Airport Pavements 447 Corps of Engineers (CBR) Method 448 The Federal Aviation Administration (FAA) Method 465 Canadian Department of Transportation (CDOT) Method 475 The Asphalt Institute Method 481 Secondary (General Aviation) Airports 497 Summary 499 15 Design of Flexible Highway Pavements 504 Differences between Airport and Highway Design Concepts 504 Differences in Design Methods 505 AASHO Flexible-Pavement Design 507 Multilayer Elastic Analysis 519 The Asphalt Institute Design 529 National Crushed Stone Association Design 536 California Method of Design 540 Minimum Surface Requirements 542 Example of the Comprehensive Design Process 550 Design Practices 550 Summary 552 PART 4 DESIGN OF RIGID PAVEMENTS 557 16 Design of Rigid Airport Pavements 559 Determination of the Modulus of Subgrade Reaction 559 Modulus of Rupture 560 Factors of Safety 561 Design Charts 561 Portland Cement Association Method 562 Corps of Engineers Method 567 Federal Aviation Administration Method 572 Base Courses 579 Compaction Requirements 580 Joint and Reinforcement Requirements 581 Jointing at Intersections 583 Design of Steel Reinforcement 586 Continuously Reinforced Concrete Pavements 591 Use of the Keel Section 592 Junction of Flexible and Rigid Pavements 592 Summary 592 17 Design of Rigid Highway Pavements 596 Development of Design 596 Test Roads 597 Definition of Pavement Types 600 Design Factors 600 Load Stresses 601 Thickness Design 602 Jointing and Reinforcement Requirements 609 Joints 611 Load-transfer Devices 612 Continuously Reinforced Concrete Pavement 614 Approach Slabs 618 Subgrades and Subbases 619 Slip-Form Construction 621 Summary 622 PART 5 PAVEMENT EVALUATION AND REHABILITATION625 18 Pavement Distress 627 Flexible Pavements 627 Rigid Pavements 636 Summary Discussion, Pavement Distress 645 19 Condition Surveys 646 Definition of Condition and Evaluation Surveys 646 Concepts of Condition and Evaluation Surveys 647 Present Serviceability Index 648 Methods of Measuring Condition 652 Present Serviceability Index Equations 659 Comparison of Methods 661 Skid Resistance 663 Summary 664 20 Strengthening Existing Pavements 665 Principles of Maintenance 665 Typical Maintenance Procedures 666 Methods of Performance Surveys 669 Methods of Structural Evaluation 670 Deflection Measurements as an Evaluation Tool 671 Interpretation of Deflection Data 674 Conversion Factors 675 Overlay Categories 676 Flexible Overlays over Flexible Pavements, Based on Deflection679 Component Layer Analysis 691 Index 699