Concreto

Investigating
21st Century Cement Production
in Interior Alaska Using Alaskan Resources

Funded by the

Fairbanks North Star Borough

Project Period: April, 2009 – December, 2010
Grant Number: 012409

Primary Investigator: GH Cole Sonafrank
Assistant Director of Research, CCHRC

CCHRC - www.cchrc.org, P.O. Box 82489, Fairbanks, AK 99708, 907-457-3454

Abstract
High performancegeopolymer cements are used commercially elsewhere in the world due to superior
performance to portland cement. These cements are stronger,1 fireproof,2 and waterproof.3,19 They
bond strongly to most materials,4 do not appreciably expand or contract,5 are foamable,6 and resistant
to salts, acids and alkalis.7,8,18 They also require less energy to make9,10,20 and are more environmentallybenign.11 Additionally, geopolymer cement can be produced in ways that make it useful for addressing a
range of everyday and extreme challenges.
Through this grant and related work, CCHRC has investigated the potential for producing geopolymer
cements using local materials and making products for the Alaskan marketplace. Based on this review,
CCHRC is optimistic about the chance for a commerciallyviable enterprise to develop. Compounding
our optimism is the potential for a new geopolymer industry to create local jobs and economic
opportunities, wisely use Alaskan resources such as fly ash and mine tailings, make products that help
address the extreme challenges of our geographical setting, and significantly reduce CO2 emissions
associated with cement manufacturing.
Geopolymers require30-60% less energy to make9,10 and release about 80% less carbon dioxide into
the atmosphere.11 Unlike portland cement, which requires a huge plant costing upwards of $150 million
to manufacture, geopolymer cement production requires only a concrete batch plant costing between
$50,000 and $200,000. In part, this is because the source materials for geopolymers are by-products
that have alreadygone through combustion in a power plant, or milling in a mine, which are processes
analogous to transforming limestone into portland cement clinker.
Five coal-fired electrical power generation plants12,13 in Interior Alaska are currently producing more
than 100,000 tons of ash per year. The Fort Knox gold mine has more than 200 million tons of finely
milled tailings accumulated in theirretention pond.14 These pre-processed materials can be used to
locally manufacture geopolymer cement, concrete and derivative products.
This project has demonstrated that fly ash from GVEA’s Healy 1 power plant and from Aurora Energy’s
Chena power plant both work as the sole active alumina-silicate source for producing geopolymer
cements. Fort Knox mine tailings are demonstrated to be a usefulfiller material and further
experimentation may confirm their potential as an active component.
The cost of producing geopolymer cement-based concrete in Fairbanks, Alaska, is approximately the
same as the cost of producing portland cement-based concrete in Fairbanks at current material prices.
The material cost for both is approximately $84 per cubic yard. The processing equipment and costs arethe same. The higher the concrete’s performance specifications are set, the more cost advantageous
using geopolymer cement becomes.
This project has moved Fairbanks significantly closer to being ready to utilize local resources presently
wasted to commercially manufacture geopolymer cements, concrete and derivative products on an
economically competitive basis.

CCHRC - www.cchrc.org, P.O.Box 82489, Fairbanks, AK 99708, 907-457-3454

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Contents
Abstract

2

Contents

3

Project Description

4

Accomplishments

5

Next Steps

9

Appendices

13

A.Footnotes

13

B. Producing Geopolymers in Interior Alaska

15

C. Alaskan Geopolymer Costs

65

D.Interior Alaska’s Geopolymer Potential

87

E. A Comparison of Portland and Geopolymer...