Australian scientists use recycled industrial plastics in concrete

PIctured from left: Tony Collister, Fibercon; Shi Yin, James Cook Univertity (JCU); Rabin Tuladhar, JCU and Andrew Smith, country chair Shell

Research by scientists at Australia's James Cook University (JCU)  to reduce the environmental cost of concrete has won an innovation award.

The technology, developed at JCU through PhD student Shi Yin’s research under the supervision of Dr. Rabin Tuladhar and in collaboration with Queensland-based company Fibercon, has won the Manufacturing, Construction and Innovation category at this year’s Australian Innovation Challenge.

“We’ve produced recycled polypropylene fibers from industrial plastic wastes. With our improved melt spinning and hot drawing process we now have plastic fibers strong enough to replace steel mesh in concrete footpaths,” says Dr. Tuladhar.

He says the use of recycled plastic in concrete makes the building product much more environmentally friendly.

“Using recycled plastic, we were able to get more than a 90% saving on CO2 emissions and fossil fuel usage compared to using the traditional steel mesh reinforcing. The recycled plastic also has obvious environmental advantages over using virgin plastic fibers.”

Concrete is second only to water as the material most commonly used by humankind, with 24 billion tonnes poured globally every year.

Use of recycled plastic fibers in concrete eliminates the need for steel mesh and saves significant amounts of carbon dioxide associated with steel production, note the researchers. Comprehensive life cycle assessment shows the production of recycled plastic fibre produces 90% less carbon dioxide and eutrophication (contamination of water bodies with nutrients) compared with the equivalent steel.

Plastic fibre already has been used in the construction of a 100-metre-long (109-yard-long) concrete footpath at JCU and precast concrete drainage pits designed by Fibercon.

Tuladhar says the next phase of the research will examine enhancing the mechanical and bond properties of
fibers using surface modification and looking into broader applications of recycled plastic fibres in other precast concrete elements.