ORLANDO, Fla. – “The addition of dialysis plastic waste to concrete leads to significant improvement in some characteristics of concrete and will lead to the environmental sustainability of health care,” John M.W. Agar, MBBC, FRACP, FRCP, said at the Annual Dialysis Conference.
In Australia about 12,000 people require hemodialysis or peritoneal dialysis treatment each year which creates more than 5,000 tons of plastic waste, according to Agar’s presentation. Dialysis waste is high-grade, pure and single-use plastic, as well as a reproducible waste source of assured quality that is generated at a regular, predictable rate.
At the conference, Agar presented findings on the feasibility of incorporating shredded and sterilized dialysis plastic waste into concrete which he said is the perfect sequestration material to “lock away” the plastic waste. Agar and team used a SteriMed 700 waste processing machine to shred and sterilize the dialysis plastic waste into polypropylene plastic fiber. The shredded hard, soft and mixed plastic was then added to concrete product in 0.5% and 1% mixes by weight, according to the presentation. A sieve analysis was then performed on the plastic waste to determine the signature of hard, soft or mixed plastic before incorporating the plastic into concrete.
When finer plastic fibers were used, there was improved bonding with the concrete matrix, according to the presented results. The addition of 0.5% and 1% of polypropylene fibers to concrete caused minor increase in tensile strength (0.8% and 8% increase, respectively), but had no impact on compressive strength. However, the addition of 1% SteriMed shredded dialysis waste plastic to concrete produced a slight reduction in compressive strength with hard (9.9%), soft (16.9%) and mixed (11.5%) plastics were added.
After the addition of plastic dialysis waste, the initial rate of water absorption by the concrete was unchanged. However, across all three plastic-concrete mixes, the secondary rate of water absorption decreased by an average of 30%.
The percentage of plastic waste and the shape of the plastic fibers significantly influence the final characteristics of the concrete, Agar and colleagues interpreted from the data.
“But there is really minimal loss of compressive strength with the observed addition of dialysis waste to concrete and that’s unlikely to impact the overall behavior of the concrete,” Agar noted in the presentation. Also, the decrease in water absorption is expected to improve the resistance of the concrete to corrosion.
Adding dialysis plastic waste to concrete creates a more flexible product that is significantly more water-proof, as well as effective at supporting light weight. This product could potentially be used to efficiently build coastal, marine and off-shore buildings and promises to be more resistant to rebar corrosion, he noted.
“The addition of dialysis waste plastic to concrete leads to significant improvements in some characteristics of concrete,” concluded Agar. “These features may lead to better long-term quality and a more durable concrete product, and further testing is indicated and is underway.” – by Marley Ghizzone and Joan-Marie Stiglich, ELS
Agar JMW, et al. Re-using dialysis plastic waste as an incorporative into concrete. Presented at: Annual Dialysis Conference; Mar. 3-6, 2018; Orlando, Fla.
Disclosure: Agar reports no relevant financial disclosures.