CIES – Promoting Sustainable Concrete Technology

The Centre for Infrastructure Engineering and Safety (CIES) continues to promote a sustainable concrete technology within the CRC for Low Carbon Living under the leadership of A/Professor Arnaud Castel and Professor Stephen Foster.

In July 2014, this new project was approved by the CRC-LCL Board with a cash contribution of $1,100,000 in combination with the in-kind contributions from partner organisations of $1,900,000.

The 2013 Scoping Study identified that the most promising sustainable option to traditional Ordinary Portland Cement (OPC) concrete is the geopolymer concrete. Geopolymer concrete is the result of the reaction of materials containing aluminosilicate such as fly ash and slag with alkalis to produce an inorganic polymer binder. Geopolymer concrete has an 80% lower carbon footprint compared to the conventional Portland cement concrete.

The major barrier to geopolymer adoption is the lack of standard specifications, track record and exclusion from current standards (e.g., AS 3600). The project submitted to the CRC-LCL in 2014 aims to gather field data from geopolymer real-life constructions to develop greater confidence in geopolymer use. Using the field and laboratory data, a comprehensive Handbook for geopolymer specification will be developed and published through Standards Australia.

Additionally, a pilot program will develop lightweight aggregates based on fly ash to produce lightweight concrete which reduces energy usage in buildings. Current technologies for producing lightweight aggregates using sintered fly ash involve carbon intensive processes. This project aims to develop low carbon processes based on geopolymerisation and alternative methods for producing aggregates from fly ash.

Partner organisations include CIES at the UNSW, Swinburne University of Technology, ADAA, ASA, AECOM, Sydney Water and Standards Australia. The project coordinators also obtained letters of support from the main Australian geopolymer concrete suppliers: Zeobond Pty Ltd, Wagners Concrete Pty Ltd, Milliken Infrastructure solutions as well as RMS Pavement Structures, Transport and Main Roads QLD, Vicroads.