Guide Specification for Service Life Design of Highway Bridges (2020)

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NCHRP Web-Only Document 269: Guide Specification for Service Life Design of Highway Bridges C-1 A P P E N D I X C Guide Specification Table of Contents Starts on following page.

GUIDE SPECIFICATION FOR SERVICE LIFE DESIGN OF HIGHWAY BRIDGES TABLE OF CONTENTS SECTION 1—INTRODUCTION 1.1—BACKGROUND ................................................................................................................................................. 1-1 1.2—OBJECTIVES ...................................................................................................................................................... 1-2 1.3—ORGANIZATION ............................................................................................................................................... 1-2 1.4—DEFINITIONS ..................................................................................................................................................... 1-2 1.5—NOTATION ......................................................................................................................................................... 1-3 1.6—APPROACH ........................................................................................................................................................ 1-4 1.7—FUTURE SERVICE LIFE DESIGN IMPROVEMENTS ................................................................................... 1-8 SECTION 2—CLASSIFICATION 2.1—TARGET SERVICE LIFE ................................................................................................................................... 2-1 2.1.1—Service Life Category ................................................................................................................................ 2-1 2.1.2—Renewable Elements .................................................................................................................................. 2-2 2.1.2.1—Joints and Bearings .......................................................................................................................... 2-2 2.1.2.2—Barriers and Railings ....................................................................................................................... 2-2 2.2—ENVIRONMENTAL CLASSIFICATION .......................................................................................................... 2-2 2.2.1—Exposure Zones.......................................................................................................................................... 2-2 2.2.1.1—Macro Environment Exposure Zones .............................................................................................. 2-2 2.2.1.2—Micro Environment Exposure Zones ............................................................................................... 2-3 2.2.2—Exposure Classes ....................................................................................................................................... 2-5 2.2.2.1—Concrete Structures .......................................................................................................................... 2-5 2.2.2.2—Steel Structures ................................................................................................................................ 2-7 2.2.2.3—Foundations and Retaining Walls .................................................................................................... 2-8 SECTION 3—GENERAL DESIGN GUIDELINES 3.1—SERVICE LIFE CONSIDERATIONS IN THE DESIGN PROCESS ................................................................ 3-1 3.2—DESIGN FOR SERVICE LIFE ........................................................................................................................... 3-1 3.2.1—Planning ..................................................................................................................................................... 3-1 3.2.2—Global Design ............................................................................................................................................ 3-3 3.2.2.1—Interaction of Bridge Components ................................................................................................... 3-3 3.2.2.2—Plan for Component Replacement ................................................................................................... 3-4 3.2.2.3—Total Bridge Service Life ................................................................................................................ 3-5 3.2.3—Deterioration Experience ........................................................................................................................... 3-5 3.2.3.1—Drainage ........................................................................................................................................... 3-5 3.2.3.2—Decks ............................................................................................................................................... 3-6 3.2.3.3—Joints and Bearings .......................................................................................................................... 3-7 3.2.3.4—Concrete Structures .......................................................................................................................... 3-9 3.2.3.5—Structural Steel .............................................................................................................................. 3-12 3.2.3.6—Foundations and Retaining Walls .................................................................................................. 3-15 3.2.3.7—Utilities and Appurtenances ........................................................................................................... 3-17 3.3—GENERAL DURABILITY CONSIDERATIONS ............................................................................................ 3-18 3.3.1—Drainage ................................................................................................................................................... 3-18 3.3.2—Deck Detailing ......................................................................................................................................... 3-19 3.3.3—Joints ........................................................................................................................................................ 3-20 3.3.3.1—Effect of Joints on Other Bridge Components ............................................................................... 3-20 3.3.3.2—Jointless Bridges ............................................................................................................................ 3-20 3.3.4—Bearings ................................................................................................................................................... 3-21 3.3.5—Utilities and Appurtenances ..................................................................................................................... 3-21 3.3.6—Wildlife .................................................................................................................................................... 3-22 3.3.7—Access and Inspection .............................................................................................................................. 3-22 3.3.8—Construction and Preservation ................................................................................................................. 3-22 3.4—DOCUMENTATION ........................................................................................................................................ 3-22 3.4.1—Service Life Design Report ...................................................................................................................... 3-22 3.4.2—Need for Preservation Plan ...................................................................................................................... 3-23 NCHRP Project 12-108 C-2

SECTION 4—CONCRETE STRUCTURES 4.1—DETERIORATION MECHANISMS AND COMMON MITIGATION APPROACHES .................................. 4-1 4.1.1—Chloride Induced Corrosion .......................................................................................................................4-1 4.1.2—Carbonation Induced Corrosion .................................................................................................................4-1 4.1.3—Freeze-thaw Attack ....................................................................................................................................4-2 4.1.4—Alkali Aggregate Reaction .........................................................................................................................4-2 4.1.5—Sulfate Attack .............................................................................................................................................4-2 4.1.6—Abrasion .....................................................................................................................................................4-2 4.1.7—Preservice Cracking ...................................................................................................................................4-2 4.2—MATERIAL-LEVEL PROTECTION STRATEGIES ......................................................................................... 4-3 4.2.1—General Requirements ................................................................................................................................4-3 4.2.2—Freeze-thaw Attack ....................................................................................................................................4-4 4.2.3—Sulfate Attack .............................................................................................................................................4-5 4.2.4—Corrosion ....................................................................................................................................................4-5 4.2.4.1—General ............................................................................................................................................. 4-5 4.2.4.2—Concrete Cover ................................................................................................................................ 4-6 4.2.4.2.1—Assumptions and Limitations.................................................................................................4-6 4.2.4.2.1a—Analysis Approach ........................................................................................................ 4-6 4.2.4.2.1b—Target Service Life ....................................................................................................... 4-7 4.2.4.2.1c—Influence of Cracking.................................................................................................... 4-8 4.2.4.2.1d—Reinforcement ............................................................................................................... 4-8 4.2.4.2.1e—Surface Treatments ....................................................................................................... 4-9 4.2.4.2.1f—Wearing Surfaces .......................................................................................................... 4-9 4.2.4.2.2—Cover Requirements............................................................................................................. 4-10 4.3—OTHER PROTECTION STRATEGIES ............................................................................................................ 4-15 4.3.1—Surface Sealers ......................................................................................................................................... 4-15 4.3.2—Detailing ................................................................................................................................................... 4-16 4.3.3—Special Provisions for Decks.................................................................................................................... 4-20 4.3.3.1—Overlays ......................................................................................................................................... 4-20 4.3.3.2—Waterproofing Membranes ............................................................................................................ 4-20 4.3.3.3—Concrete Curing ............................................................................................................................. 4-21 4.4—CONCRETE DURABILITY TESTING ............................................................................................................ 4-22 SECTION 5—STEEL STRUCTURES 5.1—DETERIORATION MECHANISMS .................................................................................................................. 5-1 5.1.1—Corrosion ....................................................................................................................................................5-1 5.1.2—Fatigue ........................................................................................................................................................5-1 5.2—PROTECTION STRATEGIES ............................................................................................................................ 5-2 5.2.1—Corrosion Protection ..................................................................................................................................5-2 5.2.1.1—General ............................................................................................................................................. 5-2 5.2.1.2—Considerations for Uncoated Weathering Steel ............................................................................... 5-4 5.2.2—Fatigue Design ...........................................................................................................................................5-5 5.3—DETAILING ........................................................................................................................................................ 5-6 5.3.1—Members ....................................................................................................................................................5-6 5.3.1.1—Corrosion Prevention ....................................................................................................................... 5-6 5.3.1.2—Fatigue Resistance ........................................................................................................................... 5-9 5.3.2—Drainage ................................................................................................................................................... 5-10 APPENDIX A5 ........................................................................................................................................................... 5-12 SECTION 6—FOUNDATIONS AND RETAINING WALLS 6.1—GENERAL ........................................................................................................................................................... 6-1 6.1.1—Quality Assurance/Quality Control ............................................................................................................6-2 6.1.2—Drainage .....................................................................................................................................................6-2 6.2—FOUNDATIONS ................................................................................................................................................. 6-2 6.2.1—Spread Footings ..........................................................................................................................................6-2 6.2.1.1—Deterioration Environment .............................................................................................................. 6-2 6.2.1.2—Protection Strategies ........................................................................................................................ 6-3 6.2.2—Driven Piles ................................................................................................................................................6-4 NCHRP Project 12-108 C-3

6.2.2.1—Deterioration Environment .............................................................................................................. 6-4 6.2.2.2—Protection Strategies ........................................................................................................................ 6-6 6.2.2.2.1—Steel Piles .............................................................................................................................. 6-6 6.2.2.2.2—Concrete Piles ........................................................................................................................ 6-8 6.2.3—Micropiles .................................................................................................................................................. 6-9 6.2.3.1—Deterioration Environment .............................................................................................................. 6-9 6.2.3.2—Protection Strategies ........................................................................................................................ 6-9 6.2.4—Drilled Shafts ........................................................................................................................................... 6-10 6.2.4.1—Deterioration Environment ............................................................................................................ 6-10 6.2.4.1.1—Lack of Adequate Concrete Cover....................................................................................... 6-10 6.2.4.1.2—Soft Bottom ......................................................................................................................... 6-10 6.2.4.1.3—Preservice Cracking ............................................................................................................. 6-10 6.2.4.2—Protection Strategies ...................................................................................................................... 6-11 6.2.4.2.1—Integrity Testing .................................................................................................................. 6-12 6.3—RETAINING WALLS ....................................................................................................................................... 6-13 6.3.1—Nongravity Cantilever Walls ................................................................................................................... 6-13 6.3.1.1—Deterioration Environment ............................................................................................................ 6-13 6.3.1.2—Protection Strategies ...................................................................................................................... 6-14 6.3.2—Anchored Walls ....................................................................................................................................... 6-14 6.3.2.1—Deterioration Environment ............................................................................................................ 6-14 6.3.2.2—Selection of PI-value ...................................................................................................................... 6-15 6.3.2.3—Protection Strategies ...................................................................................................................... 6-16 6.3.3—Soil Nails ................................................................................................................................................. 6-17 6.3.3.1—Deterioration Environment ............................................................................................................ 6-17 6.3.3.2—Selection of PI-value ...................................................................................................................... 6-17 6.3.3.3—Protection Strategies ...................................................................................................................... 6-17 6.3.3.3.1—Minimum Grout Cover (PI=0) ............................................................................................. 6-18 6.3.3.3.2—Sacrificial Steel with Minimum Grout Cover (PI=1) .......................................................... 6-19 6.3.3.3.3—Grout Filled Corrugated Plastic Sheath Encapsulation (PI=2) ............................................ 6-20 6.3.4—Mechanically Stabilized Earth (MSE) Walls ........................................................................................... 6-21 6.3.4.1—Deterioration Environment ............................................................................................................ 6-21 6.3.4.1.1—Select Granular Soils for Reinforced Fill ............................................................................ 6-21 6.3.4.1.2—Electrochemical Properties of Soils for Metallic Reinforcement ........................................ 6-22 6.3.4.1.3—Electrochemical Properties of Fills for Geosynthetic Reinforcement .................................. 6-23 6.3.4.1.4—Selection of PI-value ........................................................................................................... 6-23 6.3.4.2—Protection Strategies ...................................................................................................................... 6-24 6.3.4.2.1—MSE Facing ......................................................................................................................... 6-24 6.3.4.2.2—Steel Reinforcements ........................................................................................................... 6-25 6.3.4.2.3—Geosynthetic Reinforcements .............................................................................................. 6-26 6.4—APPROACH EMBANKMENTS....................................................................................................................... 6-28 SECTION 7—RENEWABLE ELEMENTS 7.1—JOINTS ................................................................................................................................................................ 7-1 7.1.1—Joint Systems ............................................................................................................................................. 7-1 7.1.2—Jointless Systems ....................................................................................................................................... 7-2 7.1.3—Detailing for Replacement ......................................................................................................................... 7-3 7.1.4—Joint Inspection and Maintenance .............................................................................................................. 7-3 7.2—BEARINGS ......................................................................................................................................................... 7-3 7.2.1—Bearing Types ............................................................................................................................................ 7-4 7.2.2—Service Life Performance .......................................................................................................................... 7-5 7.2.3—Corrosion Protection .................................................................................................................................. 7-5 7.2.4—Design for Replacement ............................................................................................................................. 7-6 7.2.5—Bearing Maintenance ................................................................................................................................. 7-6 7.3—RAILINGS AND BARRIERS ............................................................................................................................. 7-6 7.4—ROADWAY APPROACH SLABS ..................................................................................................................... 7-6 SECTION 8—LIFE CYCLE COST ANALYSIS 8.1—LIFE CYCLE COST METHOD .......................................................................................................................... 8-1 NCHRP Project 12-108 C-4

8.1.1—Approach ....................................................................................................................................................8-1 8.1.2—Bridge LCCA Process ................................................................................................................................8-2 8.1.3—Uncertainty .................................................................................................................................................8-3 8.2—DESIGN ALTERNATIVES ................................................................................................................................ 8-3 8.3—PLANNING HORIZON ...................................................................................................................................... 8-3 8.3.1—Analysis Period ..........................................................................................................................................8-3 8.4—SCHEDULE OF COSTS ..................................................................................................................................... 8-4 8.5—ESTIMATE OF COSTS ....................................................................................................................................... 8-4 8.5.1—Agency Costs .............................................................................................................................................8-6 8.5.2—User Costs ..................................................................................................................................................8-6 8.5.3—Vulnerability Costs ....................................................................................................................................8-7 8.6—LIFE CYCLE COSTS .......................................................................................................................................... 8-7 8.6.1—Present Value .............................................................................................................................................8-7 8.6.2—Total Life Cycle Cost .................................................................................................................................8-8 8.7—COMPARISON OF ALTERNATIVES ............................................................................................................... 8-9 APPENDIX A—PROBABILISTIC SERVICE LIFE DESIGN FRAMEWORK ....................................................... A-1 APPENDIX B—CASE STUDIES ............................................................................................................................... B-1 NCHRP Project 12-108 C-5