Economical and Crack-Free High-Performance Concrete for Pavement and Transportation Infrastructure Construction Prepared by: Kamal H. Khayat, PhD, P.Eng. (principal investigator) Iman Mehdipour, PhD Candidate (student) Missouri University of Science and Technology Final Report Prepared for Missouri Department of Transportation May 2017 Project TR201503 Report cmr17-007 TECHNICAL REPORT DOCUMENTATION PAGE 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. cmr 17-007 4. Title and Subtitle 5. Report Date Economical and Crack-Free High-Performance Concrete for Pavement and June 30, 2016 Transportation Infrastructure Construction Published: May 2017 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Kamal H. Khayat, PhD, P.Eng. http://orcid.org/0000-0003-1431-0715 00047062 Iman Mehdipour, PhD Candidate http://orcid.org/0000-0002-6841-3907 9. Performing Organization Name and Address 10. Work Unit No. Center for Transportation Infrastructure and Safety/UTC program Missouri University of Science and Technology 11. Contract or Grant No. 220 Engineering Research Lab, Rolla, MO 65409 MoDOT project #TR2015-03 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Missouri Department of Transportation (SPR) Final Report (June 23, 2014-June 30, Construction and Materials Division 2016) P.O. Box 270, Jefferson City, MO 65102 14. Sponsoring Agency Code 15. Supplementary Notes Conducted in cooperation with the U.S. Department of Transportation, Federal Highway Administration. MoDOT research reports are available in the Innovation Library at http://www.modot.org/services/or/byDate.htm. This report is available at https://library.modot.mo.gov/RDT/reports/TR201503/cmr17-007.pdf 16. Abstract The main objective of this research is to develop and validate the behavior of a new class of environmentally friendly and cost- effective high-performance concrete (HPC) referred to herein as Eco-HPC. The proposed project aimed at developing two classes of Eco-HPC for the following applications: (i) HPC for pavement construction (Eco-Pave-Crete); and (ii) HPC for bridge infrastructure construction (Eco-Bridge-Crete). The binder contents for these construction materials were limited to 320 kg/m3 3 3 3 (540 lb/yd ) and 350 kg/m (590 lb/yd ), respectively, in order to reduce paste content, cost, CO2 emissions, and shrinkage. Both Eco-HPC types were optimized to develop high resistance to shrinkage cracking as well as to secure high durability. Given the relatively low binder content, the binder composition and aggregate proportion were optimized based on the packing density approach to reduce the paste required to the fill the voids among aggregate particles. The optimized concrete mixtures exhibited low autogenous and drying shrinkage given the low paste content and use of various shrinkage mitigating strategies. Such strategies included the use of CaO-based expansive agent (EX), saturated lightweight sand (LWS), as well as synthetic or recycled steel fibers. Proper substitution of cement by supplementary cementitious materials (SCMs) resulted in greater packing density of solid particles, lower water/superplasticizer demand, and improved rheological and hardened properties of cement-based materials. A statistical mix design method was proposed and was shown to be effective in optimizing the aggregate proportioning to achieve maximum packing density. The synergistic effect between EX with LWS resulted in lower autogenous and drying shrinkage. For a given fiber content, the use of steel fibers recovered from waste tires had twice the flexural toughness of similar mixture with synthetic fibers. The optimized Eco-HPC mixtures had lower drying shrinkage of 300 μstrain after 250 days. The risk of restrained shrinkage cracking was found to be low for the optimized concrete mixtures (no cracking even after 55 days of testing). The results of structural performance of large-scale reinforced concrete beams indicated that the optimized Eco-Bridge-Crete containing ternary combination of 35% fly ash and 20% slag replacements and recycled steel fibers developed significantly higher flexural toughness compared to the MoDOT reference mixture used for bridge infrastructure applications. 17. Key Words 18. Distribution Statement Bridge decks; Bridge members; Bridge piers; Cast in place No restrictions. This document is available through the structures; Concrete; Girders; High performance concrete; Paving. National Technical Information Service, Springfield, VA Crack-free; Early-age cracking; Eco-Crete; Packing density; 22161. Shrinkage mitigating strategies, Supplementary cementitious materials 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified. Unclassified. 218 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized M SSOURI Uni,iersit;r of L. c· l. .C ~ C 1 g)·' & ·.. l Economical and Crack-Free High-Performance Concrete for Pavement and Transportation Infrastructure Construction Project Number: TR2015-03 Final Report Kamal H. Khayat, PhD, P.Eng. Iman Mehdipour, PhD Candidate June 30, 2016 ABSTRACT The main objective of this research is to develop and validate the behavior of a new class of environmentally friendly and cost-effective high-performance concrete (HPC) referred to herein as Eco-HPC. The proposed project aimed at developing two classes of Eco-HPC for the following applications: (i) HPC for pavement construction (Eco-Pave-Crete); and (ii) HPC for bridge infrastructure construction (Eco-Bridge-Crete). The binder contents for these construction materials were limited to 320 kg/m3 (540 lb/yd3) and 350 kg/m3 (590 lb/yd3), respectively, in order to reduce paste content, cost, CO2 emissions, and shrinkage. Both Eco-HPC types were optimized to develop high resistance to shrinkage cracking as well as to secure high durability. Given the relatively low binder content, the binder composition and aggregate proportion were optimized based on the packing density approach to reduce the paste required to the fill the voids among aggregate particles. The optimized concrete mixtures exhibited low autogenous and drying shrinkage given the low paste content and use of various shrinkage mitigating strategies. Such strategies included the use of CaO-based expansive agent (EX), saturated lightweight sand (LWS), as well as synthetic or recycled steel fibers. Proper substitution of cement by supplementary cementitious materials (SCMs) resulted in greater packing density of solid particles, lower water/superplasticizer demand, and improved rheological and hardened properties of cement-based materials. A statistical mix design method was proposed and was shown to be effective in optimizing the aggregate proportioning to achieve maximum packing density. The synergistic effect between EX with LWS resulted in lower autogenous and drying shrinkage. For a given fiber content, the use of steel fibers recovered from waste tires had twice the flexural toughness of similar mixture with synthetic fibers. The optimized Eco-HPC mixtures had lower drying shrinkage of 300 μstrain after 250 days. The risk of restrained shrinkage cracking was found to be low for the optimized concrete mixtures (no cracking even after 55 days of testing). The results of structural performance of large-scale reinforced concrete beams indicated that the optimized Eco-Bridge-Crete containing ternary combination of 35% fly ash and 20% slag replacements and recycled steel fibers developed significantly higher flexural toughness compared to the MoDOT reference mixture used for bridge infrastructure applications. Keywords: Bridge; Crack-free concrete; Early-age cracking; Eco-Crete; Expansive admixture; Packing density; Pavement; Shrinkage, Supplementary cementitious materials. I ACKNOWLEDGEMENT The authors would like to acknowledge the many individuals and organizations that made this research project possible. First and foremost, the authors would like to acknowledge the financial support of Missouri Department of Transportation (MoDOT) as well as the RE-CAST (REsearch on Concrete Applications for Sustainable Transportation) Tier-1 University Transportation Center (UTC) at Missouri University of Science and Technology (Missouri S&T). The authors would also like to thank the companies that provided materials required for the successful completion of this project, including LafargeHolcim, BASF, Euclid Chemical, Buildex, and Capital Sand Company, as well as Granuband Macon. The cooperation and support from Abigayle Sherman and Gayle Spitzmiller of the Center for Infrastructure Engineering Studies (CIES) is greatly acknowledged, in particular the assistance of Dr. Soo-Duck Hwang, Lead Scientist, and Jason Cox, Senior Research Specialist is highly appreciated. Valuable technical support provided by technical staff of the Department of Civil, architectural, and Environmental Engineering at Missouri S&T is deeply appreciated, in particular Brian Smith, John Bullock, and Gary Abbott. II EXECUTIVE SUMMARY This research project was undertaken to develop a new class of environmentally friendly, cost- effective, and crack-free high-performance concrete (HPC) for use in pavement (Eco-Pave- Crete) and bridge infrastructure (Eco-Bridge-Crete) applications. The binder content of these novel materials were limited to 320 kg/m3 (540 lb/yd3) and 350 kg/m3 (590 lb/yd3), respectively, in order to reduce paste content, cost, CO2 emissions, and shrinkage. The rheological properties of the Eco-HPCs