The University of South Australia, with funding from Tyre Stewardship Australia, is working to develop and test reinforced crumbed rubber concrete (CRC), for use in the residential construction industry.
CRC is made by replacing sand with crumb rubber, from end-of-life tyres, in concrete mixes.
Tyre Stewardship CEO Lina Goodman said the University of South Australia testing has assessed both the material itself and its structural properties, with encouraging results.
“Nearly 40 per cent of the annual total of approximately 9.6 million cubic metres of Australian pre-mixed concrete is used for residential construction,” Ms Goodman said.
“That volume presents a significant opportunity to consume very substantial quantities of recycled rubber, and could account for a large proportion of the 56 million end-of-life tyres Australia generates each year.”
According to Ms Goodman, CRC showed no difference in performance when compared with conventional concrete during a full-scale trial of residential slabs.
“There were no issues related to the mixing and delivery of CRC by a commercial ready-mix supplier, and the residential slab contractors working with the new product reported easy application and no difference when finishing the concrete surface,” Ms Goodman said.
“In addition, as with conventional concrete, no visual deterioration was observed on the rubber concrete slab surface after three months. All the initial results indicate that CRC in residential slabs is a promising and potentially viable alternative to conventional concrete.”
Ms Goodman said the commercial potential for CRC is considerable, with positive properties including increased toughness and impact resistance, reduced tendency for cracking and shrinkage and better acoustic and thermal insulation.
“Given the ongoing population growth that is sure to sustain a growing domestic construction industry, the work we are supporting on the development and testing of CRC is one of the most promising areas of market development,” Ms Goodman said.
“Ultimately, the aim is to find valuable uses for tyre-derived material that generate a strong domestic market, create a value for the resource and, in that way, deliver a sustainable circular economy outcome.”