CCHRC is developing geopolymer cement formulas that use local raw materials and analyzing the market potential for the product in Alaska.
Geopolymer cements use waste materials as a binder and are stronger and more sustainable than conventional Portland cements. CCHRC has studied more than 600 recipes of geopolymers made with use fly ash, a byproduct of coal combustion, from local power plants. Researchers are working to develop a product that is strong, cost-competitive and cures at the right time and temperature to be used commercially. Geopolymers are already commercially available elsewhere in the world.
Creating cement requires water, an alumina silicate material, and an alkali activator such as sodium hydroxide and sodium silicate. Nearly any product made with concrete can be made with geopolymer cements. The applications are endless for buildings, transportation, and many other areas.
They differ from Portland cements in several key ways:
- stronger and more durable
- fireproof and waterproof
- bond more strongly to most materials, including steel and aggregates
- do not appreciably expand or contract
- Are foamable
- greater resistant to salts, acids and alkalis
- Release approximately 80% less carbon dioxide into the atmosphere
- Can address both everyday and extreme challenges throughout Alaska.
One reason Portland cement is so carbon intensive is that production requires a very high temperature during the firing process. Geopolymer, on the other hand, doesn’t have to be fired. Geopolymers cure much more rapidly than Portland-based cements, with set times ranging between several minutes and a few hours. Therefore, they are not mixed at a batch plant and delivered in a redi-mix truck. Geopolymers also form a strong chemical bond with previously placed material and have relatively little expansion.
CCHRC plans to move the technology to commercial production and use, and has attracted several partners for this process.
Stages of this project have been funded by the Alaska Housing Finance Corporation, Fairbanks North Star Borough, Aurora Energy LLC, the First Alaskans Institute, and Doyon Ltd. Industrial wastes have been donated by: Golden Valley Electric Company, Aurora Energy LLC, Kinross Gold, Teck Cominco, Sumitomo Metal Mining.
Product samples were donated by: University Redi-mix, Fairbanks Sand & Gravel, HC Redi-
Mix, Sika, Euclid Chemical, BASF, WR Grace, and ET Horn.
Discounted services have been provided by MAPPA, Spenard Builders Supply, and the UAF Advanced Instrumentation Laboratory.
CCHRC submitted a report to the Fairbanks North Star Borough titled “Investigating 21st Century Cement Production in Interior Alaska Using Alaskan Resources” in the spring of 2011. Click here to read the report.