A protective coating for concrete pipes and sewers that reduces the formation of fatbergs has been developed by an engineering team from RMIT.
In the modern world, fatbergs – made of fat, oil, and grease (FOG) – have become notorious for being found in sewers around the world. FOG solidifies inside concrete pipes and sewers as it mixes with calcium with water and are known to cause 40% of all sewer blockages in Australia and 50% in the US.
The cost of these blockages as far as maintenance and rehabilitation go is estimated at $100 million in this country and US$25 billion in America. To address this issue the RMIT team created a zinc-enhanced polyurethane coating that offers a promising sustainable solution by reducing the release of calcium from concrete blocks by up to 80% compared with uncoated concrete.
The study, led by Dr Biplob Pramanik, Director of Water: Effective Technologies and Tools (WETT) Research Centre, mimicked a sewer environment under extreme conditions that rapidly sped up the fatberg formation process over 30 days. The results showed that the coating reduced the build-up of FOG on concrete by 30% compared with non-coated concrete.
“The reduction of fat, oil and grease build-up can be attributed to the significantly reduced release of calcium from coated concrete, as well as less sticking of FOG on the coating surface compared to the rough, uncoated concrete surface,” Dr Pramanik said.
Traditional coatings like magnesium hydroxide that have been widely used over the last two decades can inadvertently contribute to FOG build-up by interacting with fatty acids. The coating developed is stable in water, withstands temperatures up to 850 degrees Celsius, and is self-healing at room temperature.
Now the team has set its sights on developing an improved coating to achieve a greater reduction of FOG deposits in sewers by enhancing its self-healing capabilities and mechanical strength.
About the author
Desi Corbett
Desi is the Editor of Concrete in Australia and at the helm of our magazine for 8 years. She was behind the Institute's weekly news bulletins from 2016-2021 and is now writing our focused news items. Desi has been an engineering news and features journalist/editor across all disciplines since 2013 - part of a 30-year career writing for a wide range of industries.