Geopolymer Concrete from Regional Waste Streams (4B1 Extension)

Project Leader: Arie van Riessen (Curtin University of Technology)
Start Date: October 2007

This project aims to develop the necessary chemical and structural understanding of geopolymers made from waste products for them to be used to capture a significant share of the ready mixed and precast concrete market for a given industrial region. Research has been undertaken to assess the suitability of soluble or dissolvable silica bearing waste streams generated in any one geographical region, and to determine the role that secondary metal ion constituents in the geopolymer process play on the kinetics of formation and resulting microstructure of geopolymers.

The main focus of 2007/08 was to design, manufacture and test commercially viable ready-mixed geopolymer concrete made from the suite of regionally generated wastes. This project is being extended to encompass further demonstrations of geopolymer concrete products.

During 2007/08 the following outputs were achieved:

• The first geopolymer concrete path in Australia was laid at Curtin University of Technology with the efforts of CSRP, Curtin, Rocla, CSIRO and Boral. The path will be monitored over time to investigate the long-term durability of such concretes.
• A Geopolymer Alliance was formed with the aim to bring together research institutes, the engineering fraternity, government authorities, industrial by-product generators, cement manufacturers, chemicals suppliers, concrete aggregate suppliers, concrete manufacturers, infrastructure owners and industry regulators to cooperatively develop mutually beneficial applications for geopolymer technology.
• Geopolymers with impressive physical properties have been successfully manufactured from Bayer residue. This new material opens up opportunities for utilisation of significant amounts of industry by-product.
• Lead, chromium III, barium and silver have been encapsulated in geopolymers to pass the United States Environmental Agency recommended toxicity characterisation leaching procedure (TCLP) test for landfills.
• Radioactive elements caesium, strontium and uranium have been immobilised in geopolymers to pass regulatory tests for radioactive nuclear waste.
• Differences in stiffness of various flyash-based geopolymers (Gladstone, Tarong and Huntley) have been monitored in real-time during curing. Processing windows for a variety of flyash geopolymers have been defined using viscometry, ultrasound propagation and impedance spectroscopy.
• Rocla geopolymer concrete pipes have passed the necessary specifications and the results indicate they perform better than the equivalent Ordinary Portland Cement pipes in hydrostatic load tests.

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