Research supports ELT role in residential concrete

ADELAIDE, Australia—Researchers from the University of South Australia (UniSA) claim end-of-life tires are an economically viable and safe alternative for residential construction.

The UniSA researchers carried out trials using rubber recyclate from ELTs, and, according to the university, the research is the first to practically demonstrate and construct the new crumb rubber concrete mix in the field.

The team investigated the use of various crumb rubber and concrete mixes in residential constructions, assessing its constructability, bond strength, durability and flexural strength.

"We found that reinforced crumb rubber concrete, with up to 20 percent sand replacement by volume, is superior to conventional concrete in some ways," reported co-researcher Osama Youssf.

Property enhancements, he said, included higher impact resistance, toughness and ductility, a higher damping ratio, better thermal and acoustic insulation, and a lighter weight.

"With respect to pumping, screeding or finishing the concrete surface using a power trowel, contractors also found no difference between using the crumb rubber concrete and conventional concrete," Youssf said.

"Additionally, the ready-mix cement companies reported no concerns relating to concrete batching, delivery or mixing, and said that the wash out of the concrete truck mixer was far easier," he added.

The UniSA team said their research could open the door to an important new market for recyclate from the 1.5 billion vehicle tires discarded each year.

"By recycling ELTs in concrete, valuable natural resources can be conserved," the university said, "and the current tire landfill problem can be partially resolved."