GEORGIA DOT RESEARCH PROJECT 16-30 FINAL REPORT Phase – II Evaluation of Metakaolin for GDOT Concrete Specifications (ASTM C618 N Pozzolan) and Mass Concrete Provision OFFICE OF PERFORMANCE-BASED MANAGEMENT AND RESEARCH 600 W. PEACHTREE ST. NW ATLANTA, GA 30308 1. Report No.: 2. Government Accession No.: 3. Recipient's Catalog No.: FHWA-GA-19-1630 4. Title and Subtitle: 5. Report Date: Phase II – Evaluation of Metakaolin for GDOT Concrete November 2019 Specifications (ASTM C618 N Pozzolan) and Mass 6. Performing Organization Code: Concrete Provision 7. Author(s): 8. Performing Organization Report No.: Mi G. Chorzepa, Ph.D., P.E., Stephan A. Durham Ph.D., 16-30 P.E., and Hiwa Hamid 9. Performing Organization Name and Address: 10. Work Unit No.: University of Georgia College of Engineering 11. Contract or Grant No.: Driftmier Engineering Center, Athens, GA 30602 PI# Phone: (706) 357-0038 Email: [email protected] 12. Sponsoring Agency Name and Address: 13. Type of Report and Period Covered: Georgia Department of Transportation Final; August 2016-November 2019 Office of Performance-Based Management and Research 14. Sponsoring Agency Code: 600 W. Peachtree St. NW Atlanta, GA 30308 15. Supplementary Notes: Prepared in cooperation with the U.S. Department of Transportation, Federal Highway Administration. 16. Abstract: This report includes both experimental and analytical investigations of concrete mixtures containing supplementary cementitious materials to identify sustainable alternatives to Class F fly ash for use in Georgia’s mass concrete structures. The primary goal of this study is to identify concrete mixtures that reduce the potential for thermal cracking caused by the heat of hydration of cementitious materials in order to optimize long-term performance of massive concrete structures. Through this study, the research team has identified ternary replacement mixtures potentially suitable for mass concrete placements. Additionally, the team has developed temperature prediction models based on a coupled thermal-structural analysis to aid in maximum temperature and temperature differential predictions. Among the 45% cement replacement mixtures considered in this study, the ternary mixture with 30% slag and 15% metakaolin replacements achieves superior performance in terms of mechanical properties, durability, and thermal cracking potential from heat of hydration. The research team recommends that GDOT consider changes to the Special Provisions to Section 500 (see Appendix A) and further study the performance of two ternary mixtures containing a 70% cement replacement with 1) 40% slag + 30% fly ash and 2) 55% slag + 15% metakaolin in order to reduce the potential for thermal cracking, which undermines the durability of mass concrete structures in Georgia. 17. Keywords: 18. Distribution Statement: Metakoalin, Slag Cement, Fly Ash, Heat of Hydration, Mass Concrete, Bridge Seal, Temperature, Temperature Differential, Binary, Ternary Mixture 19. Security 20. Security Classification (of this 21. No. of Pages: 22. Price: Classification page): 347 (of this report): Unclassified Unclassified Form DOT 1700.7 (8-69) ii GDOT Research Project 16-30 Phase II – Evaluation of Metakaolin for GDOT Concrete Specifications (ASTM C 618 N Pozzolan) and Mass Concrete Provision Final Report By Mi G. Chorzepa, Ph.D., P.E. Associate Professor of Civil Engineering Stephan A. Durham, Ph.D., P.E. Professor of Civil Engineering Hiwa Hamid Ph.D. Candidate University of Georgia College of Engineering Contract with Georgia Department of Transportation In cooperation with U.S. Department of Transportation Federal Highway Administration November 2019 The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views of the Georgia Department of Transportation or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. iii TABLE OF CONTENTS Page TABLE OF CONTENTS ................................................................................................ iv LIST OF TABLES ............................................................................................................ x LIST OF FIGURES ........................................................................................................ xii EXECUTIVE SUMMARY .......................................................................................... xxii ACKNOWLEDGEMENTS ........................................................................................ xxiv 1. INTRODUCTION ........................................................................................................ 1 BACKGROUND .............................................................................................................. 1 Concrete Behavior and Elevated Temperature .................................................................... 1 Simple facts about thermal loading and concrete behavior ............................................. 1 Temperature increase or decrease .................................................................................... 3 Uniform temperature increase and gradient temperature ................................................. 3 Behavior of concrete members ........................................................................................ 5 Thermal stress and restraints............................................................................................ 6 Supplementary Cementitious Materials ............................................................................... 7 PROBLEM STATEMENT ............................................................................................... 11 RESEARCH OBJECTIVES .............................................................................................. 13 RESEARCH SIGNIFICANCE AND SCOPE ........................................................................ 13 RESEARCH METHODOLOGY ........................................................................................ 14 Task 1. Perform Extensive Literature Review ................................................................... 14 Task 2. Design, Batch, and Test Concrete Mixtures with Three Metakaolin Products ..... 14 Task 3. Design, Construct, and Quantify Temperature Rise in Mass Concrete ................ 14 Task 3.1 ‐ Design test procedures for mass concrete mixtures ...................................... 14 Task 3.2 – Construct cube molds and specimens .......................................................... 15 Task 3.3 – Internal temperature monitoring in test specimens ...................................... 16 Task 4. Evaluation of Maximum Temperature Limits ...................................................... 16 Task 4.1 – Thermal and structural modeling ................................................................. 16 Task 4.2 – Design and construct test specimens ............................................................ 16 Task 4.3 – Evaluation of temperature limits .................................................................. 17 Task 5. Data Analysis and Synthesis of Findings .............................................................. 18 IMPLEMENTATION ...................................................................................................... 18 iv ORGANIZATION OF THE REPORT ................................................................................. 18 2. COMPARISON OF BINARY AND TERNARY MIXTURES .............................. 21 PRELIMINARY INVESTIGATION INTO HEAT OF CEMENTITIOUS MATERIAL HYDRATION . ................................................................................................................................... 21 Experimental Design ......................................................................................................... 21 Results ............................................................................................................................... 23 Heat of hydration in binary mixtures including metakaolin .......................................... 23 Heat of hydration of ternary and other binary replacement mixtures ............................ 25 Heat of hydration of ternary mixtures with various percentages of slag and metakaolin .. ....................................................................................................................................... 27 Analysis of Results ............................................................................................................ 29 Effect of metakaolin binary mixture on heat of hydration ............................................. 29 Effect of binary mixtures containing fly ash and slag on heat of hydration .................. 30 Effect of ternary mixtures on heat of hydration ............................................................. 30 Estimating the Heat Generated from Pozzolanic Materials ............................................... 32 Estimated heat of hydration in binary mixtures including metakaolin .......................... 34 Estimated heat of hydration in ternary and alternate binary mixtures ........................... 34 MECHANICAL PROPERTIES AND DURABILITY RESULTS .............................................. 35 Fresh Properties ................................................................................................................. 38 Binary Metakaolin Hardened Properties ...........................................................................