Chapter 14: Geopolymer Cement and Concrete
Authors:
Arie van Riessen, Curtin University of Technology, Perth, WA
Nigel Chen-Tan, Curtin University of Technology, Perth, WA
Joanne Portella, Engineered Material Solutions
Stefan Bernard, Engineered Material Solutions
Terry Gourley, Geopolymer Alliance
Summary:
A number of chapters in this handbook have described fly ash in great detail, including a comprehensive microstructural analysis (Chapter 2). The fact that fly ash has a large component of amorphous aluminosilicate (Ward & French 2006; Williams & van Riessen 2010) makes it ideal for the production of geopolymer. This chapter will describe aspects of the use of fly ash in geopolymer mixes. The word geopolymer was coined for the cement-like material produced by alkali activation of amorphous aluminosilicate feedstock (Davidovits 1991). Geopolymer is a cement/concrete material that has the potential to change the current image of CCPs as an industrial waste and a problem into a valuable resource for the production of useful materials.
Unlike traditional Ordinary Portland Cement (OPC), geopolymer cement production, utilising waste materials such as fly ash and slag, results in low CO2 emissions. For every tonne of OPC produced, a similar amount of CO2 is emitted into the atmosphere (Davidovits 1991). In comparison, it is estimated that for every tonne of geopolymer concrete produced there will be a reduction of approximately 44−64% in the CO2 emitted relative to OPC-based concrete (McLellan et al. 2011). The emissions from production of geopolymer concrete are due to the production of aggregates (as for OPC concrete), the power required for processing the geopolymer concrete (as for OPC concrete), and the manufacture of the alkaline silicate activator. Geopolymer technology has the potential to initially supplement and ultimately replace sectors of the OPC industry, thus providing a “green” concrete alternative, utilising low-cost by-products to produce materials of potentially superior quality and functionality. However, additional research is required to prove the durability and structural performance of geopolymer-based materials.
Index:
- 14.1 Introduction
- 14.2 Proposed Chemistry
- 14.3 Effect of Different Processing Variables
- 14.4 Geopolymers from Australian Fly Ash
- 14.5 Applications
- 14.6 Summary
- 14.7 Acknowledgements
- 14.8 References
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