Design and Construction Considerations for Hydraulic Structures Roller-Compacted Concrete Second Edition U.S. Department of the Interior Bureau of Reclamation Technical Service Center Denver, Colorado September 2017 MISSION STATEMENTS The U.S. Department of the Interior protects America’s natural resources and heritage, honors our cultures and tribal communities, and supplies the energy to power our future. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Cover photos: (top) Aerial view of Upper Stillwater Dam, Utah, the Bureau of Reclamation’s first RCC gravity dam; (right) Upper Stillwater Dam during construction. Design and Construction Considerations for Hydraulic Structures Roller-Compacted Concrete Second Edition U.S. Department of the Interior Bureau of Reclamation Technical Service Center Denver, Colorado September 2017 PREFACE Since Upper Stillwater Dam was designed and constructed in the 1980s, the Bureau of Reclamation (Reclamation) has used roller-compacted concrete (RCC) for a wide variety of applications, including stability buttresses for masonry gravity and concrete arch dams, overtopping protection and upstream slope protection for embankment dams, new gravity dams, new spillways and spillway stilling basins, tailrace dikes, and overflow weirs. This manual provides guidelines for the design and construction of various types of dams and hydraulic structures using RCC, based largely on the experience gained by Reclamation engineers from RCC projects completed over the past 30 years. The information provided herein is intended to emphasize the importance and versatility of RCC as both a material and a construction method. It can serve as a starting point for the design of hydraulic structures using RCC; however, this information is basic and is not intended to serve as a comprehensive design guide. The information is organized as follows: Chapter 1: Definition of RCC and scope of the manual Chapter 2: Background information, including history, philosophy, and practical uses of RCC Chapter 3: Discussion of RCC materials Chapter 4: Design requirements for RCC mixtures, including RCC properties and mixture proportioning procedures Chapter 5: Construction methods, from batching through final testing Chapter 6: Design considerations for new RCC gravity dams Chapter 7: Design considerations for RCC buttresses for concrete dam modifications Chapter 8: Design applications for embankment dams, including overtopping protection, upstream slope protection, water barrier, and replacement structures Chapter 9: Other design applications for RCC Chapter 10: Case histories that illustrate the design, construction, and performance of a variety of RCC projects Design and Construction Considerations for Hydraulic Structures In addition, appendices are included that contain guide specifications for RCC construction (appendix A), a summary of RCC costs (appendix B), and samples of adiabatic temperature rise tests of RCC (appendix C). This manual was developed by Reclamation authors and contributors. Authors of the first edition included (in alphabetical order) Tim Dolen, Tom Hepler, Daniel Mares, Larry Nuss, Doug Stanton, and John Trojanowski. Elizabeth Cohen and Chuck Cooper provided additional information for the case histories. Betty Chavira prepared the RCC guide specifications. John LaBoon and Gregg Scott provided the peer review. Lelon A. Lewis performed technical editing of the manual. Authors of the second edition included (in alphabetical order) Jeff Allen, Veronica Madera, Daniel Mares, and Jerzy Salamon. Walt Heyder and Janet White provided the peer review. Teri Manross performed technical editing of the manual. Nancy Arthur compiled the revised RCC guide specifications, which are in appendix A. Funding for this manual was provided by Reclamation’s Dam Safety Office, Technical Service Center, and Office of Policy. The authors would like to thank these offices for their joint effort in support of the development and publication of this manual. ABBREVIATIONS AND ACRONYMS % percent °C degrees Celsius °F degrees Fahrenheit ACI American Concrete Institute AEA air-entraining admixture AFP Annualized Failure Probability ALL Annualized Life Loss ASR alkali-silica reaction ASTM American Society for Testing and Materials C:P cement to pozzolan (ratio) C+P cement plus pozzolans CRB Consulting Review Board DOT Department of Transportation FE Finite Element FEMA Federal Emergency Management Agency ft3 cubic feet ft3/s cubic feet per second GERCC grout-enriched roller compacted concrete GEVR grout-enriched vibratable roller compacted concrete GMSS Gravity Method of Stress and Stability lb pounds lb/ft3 pounds per cubic foot lb/in2 pounds per square inch lb/yd3 pounds per cubic yard LOI loss on ignition MCE maximum credible earthquake MWD Maricopa Water District NEPA National Environmental Policy Act NMSA nominal maximum size aggregate PMF probable maximum flood PVC polyvinyl chloride RCC roller-compacted concrete Reclamation Bureau of Reclamation USACE United States Army Corps of Engineers USFS United States Forest Service w/cm water to cementitious materials WRA water-reducing admixture yd3 cubic yards yd3/d cubic yards per day yd3/hr cubic yards per hour 2D two-dimensional 3D three-dimensional CONTENTS Page 1. Definition and Scope...................................................................................... 1 1.1 References ........................................................................................... 2 2. Background.................................................................................................... 3 2.1 History of RCC Development ............................................................. 3 2.2 Concrete Mix Design Philosophy........................................................ 4 2.3 Practical Applications of RCC ............................................................ 5 2.4 References ........................................................................................... 6 3. RCC Materials ............................................................................................... 7 3.1 Water ................................................................................................... 7 3.2 Cementitious Materials........................................................................ 7 3.2.1 Cement ......................................................................................... 7 3.2.2 Pozzolan .................................................................................. 8 3.3 Admixtures .......................................................................................... 9 3.3.1 Chemical Water-Reducing Admixtures .................................. 9 3.3.2 Air-Entraining Admixtures.................................................... 10 3.4 Aggregates......................................................................................... 10 3.4.1 Aggregate Grading ................................................................ 11 3.4.2 Aggregate Quality ................................................................. 13 3.4.3 Aggregate Production, Stockpiling, and Testing................... 13 3.5 References ......................................................................................... 14 4. RCC Mixture Design Requirements ............................................................ 15 4.1 Properties of Fresh RCC.................................................................... 16 4.1.1 Vebe Consistency.................................................................. 16 4.1.2 Segregation Potential............................................................. 20 4.1.3 Temperature........................................................................... 20 4.1.4 Density................................................................................... 20 4.2 Properties of Hardened RCC............................................................. 20 4.2.1 Compressive Strength and Elastic Properties........................ 21 4.2.2 Cement Plus Pozzolan Content and Cement to Pozzolan Ratio........................................................................................... 24 4.2.3 Thermal Properties ................................................................ 24 4.2.4 Durability............................................................................... 26 4.3 Bond Between Lifts........................................................................... 26 4.4 Field Adjustments During Construction............................................ 30 4.5 Mixture Proportioning Procedures for RCC ..................................... 34 4.5.1 Mixture Proportioning........................................................... 34 4.5.2 Steps in Proportioning RCC Mixtures................................... 35 4.6 References ......................................................................................... 39 i Design and Construction Considerations for Hydraulic Structures CONTENTS (continued) Page 5. RCC Construction Methods......................................................................... 41 5.1 General Construction Considerations................................................ 41 5.2 Aggregate Production........................................................................ 41 5.3 Batching and Mixing........................................................................