The Concrete Institute of Australia, with the assistance of the Geopolymer Alliance, have published a recommended practice document on using geopolymer concrete as an alternative to Ordinary Portland Cement (OPC) concrete.
The document looks at the innovative cement binder which uses different chemistry to traditional OPC binders to make concrete.
With cement production one of the world’s largest generators of greenhouse gases (5-8% GHG), alternatives to OPC concrete products can significantly reduce carbon dioxide emissions.
Concrete Institute of Australia CEO Graeme Burns said that when the Institute conducted international research into recommended and best practice use of geopolymer concrete, there simply wasn’t anything available.
“After completing our research, we recognised there was a gap in documented standards for the use of geopolymer concrete.
“We commissioned a project to develop these standards and believe we have a world’s first in this area,” said Burns.
In 2008, the Concrete Institute of Australia formed a focus group to write the recommended practice document. The group consisted of Australia’s experts in geopolymer concrete research and development, cement and concrete industry representatives and was chaired by Dr Terry Gourley of the Geopolymer Alliance.
The document is co-authored by Parsons Brinckerhoff geotechnical technical executive Mark Drechsler.
Drechsler, who worked with other focus group members on the document for more than three years, said that one of the benefits of this new concrete is the use of industrial waste materials such as fly ash and slags.
“The geopolymer concrete has many properties such as early high strength, low shrinkage and low heat of hydration, all of which have many potential benefits for the precast concrete products industry.
“With the recently approved carbon tax in Australia, the additional benefits of up to 80 per cent reduction in carbon emissions from using these geopolymer concrete products will provide even more incentive for the construction industry to switch to “green” concrete alternatives,” said Drechsler.
With geopolymer based concrete now available in Australia, the recommended practice document was produced to help end users, designers and decision makers consider the benefits of using geopolymer concrete compared to traditional concrete.
Geopolymer cement is made by activating amorphous alumino-silicate materials, such as fly ash and slag, with alkali-based chemicals such as sodium hydroxide and sodium silicate. The geopolymer cement is then used as a binder for sand and aggregates to produce geopolymer concrete products.