Eight million tonnes of CO2 are produced in Australia each year, as well as 14 million tonnes of fly ash and three million tonnes of slag. By substituting Portland cement with slag and fly ash to make Geopolymer Concrete (GPC), significant CO2 reduction and economic benefit can be achieved.
In a world-first project, the CRC for Low Carbon Living (CRCLCL) has partnered with NSW Ports to beneficially utilise co-products from coal-fired power stations and iron and steel manufacturing into low-carbon geopolymer concrete bollards to protect the coastline at Port Kembla from extreme weather events.
To do this, CRC-LCL worked with the maritime and concrete industries to perfect GPC for use in coastal constructions through research and development. The Ash Development Association of Australia provided specialist materials for the project. A batch of 18 Hanbar units made from high-density GPC were placed in the northern breakwater at Port Kembla NSW. These high-density breakwater armour units are monitored regularly for stability and integrity, providing a benchmark for the future use of GPC. Using steel furnace slag aggregates, these hanbar units achieved very high densities which are desirable attributes for coastal construction applications.