End-of-life tyres could be the way forward for the Australian residential construction industry with tests revealing performance parity between conventional concrete and Crumbed Rubber Concrete.

Researchers at the University of South Australia are working on a project funded by Tyre Stewardship Australia to develop and test reinforced Crumbed Rubber Concrete (CRC) for use in Australia’s residential construction industry. With nearly 40 percent of the annual total of approximately 9.6 million cubic metres of pre-mixed concrete being used for residential construction in Australia, there is considerable opportunity to consume substantial quantities of recycled rubber sourced from the 56 million end-of-life tyres generated in the country each year.

Crumb rubber from end-of-life tyres partially replaces sand in the concrete mix. After assessing both the material and its structural properties, the researchers have found that there is no difference in CRC performance when compared with conventional concrete in the full-scale trial residential slabs constructed at the university.

There were no issues related to the mixing and delivery of CRC by a commercial ready-mix supplier while the residential slab contractors working with the new product reported easy application and no difference when finishing the concrete surface. Similar to conventional concrete, there was no visual deterioration on the rubber concrete slab surface after 3 months.

Even the preparation of crumbed rubber need not be a costly and time-consuming exercise. The simple process requires the rubber to be washed and dry mixed with cement to produce a very robust product at no additional cost.

The initial results are very encouraging for CRC in residential slabs, with the recycled material presenting a potentially viable alternative to conventional concrete.

Given CRC’s performance and positive properties such as increased toughness and impact resistance, reduced tendency for cracking and shrinkage, and better acoustic and thermal insulation, the material shows considerable commercial potential.

While the technical research and testing work by the University of South Australia will continue, the initial positive results have been welcomed by TSA CEO Lina Goodman as an example of the organisation supporting research and development that will drive greater domestic use of recycled tyre-derived material.

“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. 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.”

Image: researchgate.com