Influence of Low Molarity Sodium Hydroxide and Curing on Mechanical Properties of Geopolymer

In recent years, researchers have focused on finding an alternative to Portland cement in order to reduce carbon footprint. One such alternative is identified to be geopolymer which consists of fly ash, sodium silicate, and sodium or potassium hydroxide (NAOH or KOH). Although measured strength is sufficient for infrastructure application, the high molarity of NAOH creates hazardous working environment. Therefore, the focus of this study was to evaluate the feasibility of using low molarity (4M) sodium hydroxide in combination with fly ash (Class F) and sodium silicate to produce mortar and evaluate compressive and tensile strength. In addition, Free-Free Resonant Column tests were also performed to identify influence of curing temperature on change in strength of low molarity geopolymer. Molar ratio of H2O/Na2O between 10.65 and 14.3 produced good workable mortar. The strength and moduli test results suggested that measured properties increased with increase in temperature and time of curing. However, the measured properties decreased with curing of more than 3 days at higher temperatures. Since change in water content influenced measured strength and moduli, a multi linear regression model was developed to predict amount of water evaporated from specimens based on surface area, curing temperature and curing duration. Non-destructive testing in conjunction with the proposed model can be used to monitor strength gain in the field, in the future.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFN10 Basic Research and Emerging Technologies Related To Concrete.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Inti, Sundeep
  • Hernandez, Maria Gisel
  • Tandon, Vivek
  • Tarquin, Anthony J
• Conference:
  • Transportation Research Board 93rd Annual Meeting
  • Location: Washington DC
  • Date: 2014-1-12 to 2014-1-16
• Date: 2014

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 18p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Compressive strength; Curing agents; Fly ash; Greenhouse gases; Moisture content; Nondestructive tests; Portland cement; Sodium hydroxide; Tensile strength
• Subject Areas: Highways; Materials; I30: Materials;

Filing Info

• Accession Number: 01519322
• Record Type: Publication
• Report/Paper Numbers: 14-4703
• Files: TRIS, TRB, ATRI
• Created Date: Mar 24 2014 12:02PM