Tyre Stewardship Australia-accredited recycler Lomwest Enterprises is exploring new applications and opportunities for its wall system incorporating end-of-life tyres.
Tyres sandwiched between slabs of concrete may not sound terribly exciting, but there are plenty of reasons to get enthusiastic about just that.
West Australian company and Tyre-Stewardship-Australia (TSA)-accredited recycler Lomwest Enterprises has created a high-performance wall system out of baled used tyres contained within highly stable concrete skins. Its applications include retaining walls, sound barriers, sea and blast walls, cyclone shelters and even race track impact barriers.
The modules for the flexible use walling system – called C4M – are manufactured offsite by accredited precasters, allowing quick, easy and safe onsite construction. The outer surfaces of the C4M can be architecturally modified to fit in with or enhance their environment.
The Perth company and its founder, Cliff Strahan, have been working on the C4M tyre bale system for 14 years, and have achieved a wide range of successful applications that demonstrate the wall system’s capabilities.
Each C4M module contains 100 tightly baled used car tyres, sandwiched between precast panels and can be up to 2.4 metres in height. They also meet Australian and New Zealand stability, durability and relevant load standards, including for cyclone shelter construction and as fire-rated partition walls. Modules can be linked to produce structures of any practical height and length, be they retaining walls, coastal protection barriers, noise walls, blast walls, ROM (run of mine) walls, even eco-house walls.
The C4M walls are designed to be effective in applications requiring energy absorption and stability such as with noise or in seaside and shifting soil applications. In addition, their fire-retardant properties, given the heat and oxygen limiting nature of the concrete sandwich construction, provide added value in fire risk areas.
The C4M modules have been certified by the Confederation of Australian Motorsport for use as impact barriers at Barbagallo racetrack, for instance. The modules have even been blast tested by the Australian SAS with a 30-kilogram ANFO explosive and have remained relatively intact.
The C4M wall modular construction process offers economic benefits due to speed of construction and lower labour costs. Those benefits are added to the obvious environmental gain from offering a valuable new use of end-of-life tyres.
A recent example of successful installation is at British Petroleum’s Kwinana refinery. There, the modules have been used for a blast wall to protect infrastructure and personnel. Over 60 lineal metres of three-metre-high wall was manufactured and installed within four days of receiving the order.
Operational testing of C4M walls as sound barriers is underway in several WA municipalities, with its use as canal retaining also being assessed.
As befits a product that has a high recycled content, the C4M module is also highly recyclable due to the relatively flexible nature of the tyre bale. At the end of an application’s life, the concrete faces can be simply crushed off by an excavator using a demolition grab, leaving the tyre bale intact for reuse with new face panels. The old concrete that was removed is also capable of being recycled.
Lomwest is just one of the many TSA-accredited recyclers focused on developing, commercialising and promoting new uses for old tyres, as well as creating better solutions for existing needs. Examination of the C4M walls for independent assessment, undertaken by Curtin University in Perth, is funded through the TSA Market Development program – the objective of which is to fully quantify the benefits from incorporating used tyres in such applications.
“We are very pleased to be working with Lomwest and Curtin University on this exciting research,” TSA Market Development Manager Liam O’Keefe says. “Developing the market for end-of-life tyres requires multiple outlets providing for a diverse range of applications. That includes a balance of highly refined and high-value products, incorporating powder and crumb, to high-volume and low-process applications. The C4M product provides a valuable contribution to creating a diverse and vibrant market for tyre-derived products.”
The testing – a collaboration between TSA, Curtin University, Lomwest and engineering firm BG&E – will ascertain the finite strength of the C4M modules and create a design manual to assist engineers and designers in better applying the technology.
“Designers, engineers and industry all need products that are easy to use and with clear performance properties. The ease of C4M’s use is clear, the performance, in varying applications, that we are now quantifying,” Mr O’Keefe says.
He adds that innovations such as the C4M walls can show the way forward in creating new green job opportunities and broader economic benefits from a previously intractable environmental challenge.
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