Geopolymer Concrete from Regional Waste Streams (4B1)

This project is now complete. Further work is being carried out under the 4B1 Extension project.

Project Leader: Arie van Riessen (Curtin University of Technology)
Start Date: June 2004

This project aimed to develop the necessary chemical and structural understanding of geopolymers made from waste products for them to be used to capture a significant market share of the ready-mixed concrete (and precast concrete) for a given industrial region.

The use of waste streams containing primary metal ions (Si and Al) to produce a commercially competitive ready-mixed concrete with significantly superior physical properties to that of conventional Ordinary Portland Cement concrete will:

• consume waste materials;
• generate considerable carbon credits by significantly reducing carbon dioxide emissions per tonne of concrete; and
• allow the capture of a significant market share of the ready-mixed concrete (and precast concrete) in the particular region under study.

To be able to blend a variety of waste streams, it is necessary to understand the role of secondary metal ions (Fe, Ca, Mg, Ti, etc) in the geopolymerisation process. It also necessary to understand how these interactions change when the primary and secondary ions originate from different particles within a mixture, as distinct from being present in the one feedstock particle. Of significant interest is how these secondary metal ions impact on reaction kinetics and entropy, and on hardened concrete properties.

Once reaction models are developed, they should allow theoretical optimisation of feedstock blends, and predict ways to enhance feedstock reactivity by process or material modifications within the waste generating process, minimise concrete manufacturing costs, and enhance hardened concrete properties.

The research objectives were to:

• Assess the suitability of soluble or dissolvable silica bearing waste streams generated in any one geographical region, for use as geopolymer concrete feedstocks.
• Determine the role that secondary metal ion constituents in the geopolymer process play on the kinetics of formation and resulting microstructure of geopolymers.
• Design, manufacture and test commercially viable ready-mixed geopolymer concrete made from the suite of regionally generated wastes.
• Investigate the long-term durability of such concretes.

> view the "Geopolymer Concrete from Regional Waste Streams" (4B1 Extension) project