Deakin University has a lab full of concrete spa baths. These spa baths aren’t made of concrete, but rather they are spa baths to put pieces of concrete into. This is all part of a project to test salt water and weather effects on concrete, and to produce concrete that is more durable.
The corrosion of steel bars used in concrete construction is a major issue, and the team at Deakin is testing a plastic additive in the concrete mix, with the expectation that it will extend the service life of concrete buildings, pools and retaining walls.
The plastic they are using is high-grade single use plastic, left over from dialysis treatment in hospitals. This is ordinarily a waste product and with more than 12,000 Australians on dialysis, about 5,100 tonnes of this plastic waste is produced per year.
The concrete researchers, led by Dr Riyadh Al-Ameri, have added a two per cent measure of elongated plastic fibres to a normal concrete mix without removal of any original mix component. Dr Al-Ameri is a senior lecturer in structural engineering, and began his career working in concrete construction as a site engineer on large housing projects.
‘Concrete can crack and damage the internal bond, which can then lead to water penetration and corrosion of the steel bars, critical for providing the strength and integrity of concrete structures,’ he explains.
‘If we are able to facilitate the production of new types of concrete that will offer better protection, give structures longer life and better performance, as well as help recycle plastic waste, that will be a great achievement.’