Re-using Plastic for Corrosion Prevention
Could a Life-Saving Plastic be a Long-Lasting Solution for Concrete Corrosion?
Each year, hospitals around the world throw away tonnes of plastic waste as a result of performing life-saving dialysis treatments. A shared interest in sustainability is what brought Dr Riyadh Al-Ameri, a structural engineering lecturer from the Deakin University, and Dr. Katherine Barraclough, a nephrologist from the Royal Melbourne Hospital, together. Dr Al-Ameri is leading a research project that repurposes plastic waste for use in concrete construction.
The Cost of Hazardous Waste
Hemodialysis, a common dialysis treatment, is dependent on plastic apparatus. As Dr. Barraclough explains, during hemodialysis “blood is pumped from a patient's bloodstream through a machine then back to the patient. This removes toxins and excess water and is life sustaining for patients with kidney failure."
For health and safety reasons, once the plastic is used it must undergo a process of sterilization and incineration to be discarded. This waste management process has a costly environmental toll. According to Dr Al-Ameri, the one-time use model for the plastic has to be reconsidered based on the impact it will have in the future. “With increasing numbers of people requiring dialysis in Australia and worldwide, we need to work out ways to reduce the costs of care delivery, as well as play our part in ensuring a healthy environment for future generations," he says.
Solving Two Problems with One Solution
Instead of throwing the plastic away after it is sterilized, this project makes use of it by shredding it and adding it to a concrete mix. Dr Al-Almeri and his team of researchers using this method to test whether the plastic waste protects concrete structures from corrosion.
During initial tests “shredded plastic waste [was added] to a concrete mix at concentrations of 0.5 per cent and 1 per cent by weight of concrete, with results showing this made a product that was more durable and significantly more water-proof.”
Protecting concrete structures against exposure to water is a crucial step that can prevent concrete corrosion from occurring. Corrosion occurs when the steel reinforcement is exposed to elements that cause it to rust. Dr Al-Ameri states, "wet and dry cycles can have a big impact on the durability of the concrete, [specifically for costal areas, considering that] sea water has chloride, which is very harmful to both concrete and steel reinforcement.”
Since structural damage is inevitable in concrete, finding a solution to corrosion in reinforced concrete will play a major role in the industry. Under normal conditions, concrete corrosion is a long-term challenge that is often detected in the later life stages of a structure because it takes years of the damage to form and become visible. But in a marine environment, corrosion rate occurs much more rapidly.
Funding from Fresenius Medical Care, a global provider of dialysis products and services, has enabled this project to take on more rigorous testing. Tests will determine if this new concrete mix can withstand harsher conditions. The potential impact of this research project is two: it directly improves waste management for a material that saves lives and may be the innovative solution that will save structures from the devastating impact of concrete corrosion.
Source: Deakin University