Phase II – Evaluation of Metakaolin for GDOT Concrete Specifications (ASTM C618 N Pozzolan) and Mass Concrete Provision

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.

Language

  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 371p

Subject/Index Terms

Filing Info

  • Accession Number: 01745974
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-GA-19-1630
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jul 17 2020 12:27PM