World-first project to ‘self heal’ cracked concrete using sludge could save $1.4 billion repair bill to Australia’s sewer pipes
Mar 01, 2023
Water treatment sludge could be used to prevent 117,000 kilometres of sewer pipes in Australia from cracking in future, without any intervention by humans, helping to save $1.4 billion in annual maintenance costs.
A world-first project led by University of South Australia sustainable engineering expert Professor Yan Zhuge is trialling a novel solution to halt unprecedented levels of corrosion in the country’s ageing concrete pipelines.
Corrosive acid from sulphur-oxidising bacteria in wastewater, along with excessive loads, internal pressure and temperature fluctuations are cracking pipes and reducing their life span, costing hundreds of millions of dollars to repair every year across Australia.
Self-healing concrete, in the form of microcapsules filled with water treatment sludge, could be the answer.
“Sludge waste shows promise to mitigate microbial corrosion in concrete sewer pipes because it works as a healing agent to resist acid corrosion and heal the cracks,” Prof Zhuge says.
Researchers will develop microcapsules with a pH-sensitive shell and a healing agent core containing alum sludge – a by-product of wastewater treatment plants – and calcium hydroxide powder. The combination will be highly resistant to microbially induced corrosion (MIC).
It will be embedded inside the concrete at the final step of mixing to protect it from breakage. When the pH value changes as acid levels build up, microcapsules will release the healing agents.
“This technology will not only extend the lifetime of concrete structures, saving the Australian economy more than $1 billion, but it will promote a circular economy as well by reusing sludge that would normally end up in landfill,” Prof Zhuge says.
Existing repairs of deteriorating concrete not only cost millions, but they are often short-lived, with 20 per cent failing after five years and 55 per cent failing after 10 years.
Existing methods to contain acid corrosion in sewer pipes are unsuccessful for a variety of reasons.
Chemicals can be added to wastewater to alter the sewer environment and stop corrosion, but they contaminate the environment and are also costly. Another option involves increasing the speed of sewage flow by amending the pipe hydraulics, but this is not always effective. Surface coating is another popular option, but it is time consuming, and the effect is temporary.
“Improving the concrete mixture design is the preferred method for controlling microbially induced corrosion. Using self-healing concrete that can seal cracks by itself without any human intervention is the solution.”
To be carbon-neutral by 2050, the construction industry is being forced to transit to a circular economy, Prof Zhuge says.
“Industry by-products or municipal wastes that would normally be discarded in landfill sites, potentially generating pollution, may now be reused in the construction production chain.
“Mainland Australia alone has about 400 drinking water treatment plants, with a single site annually generating up to 2000 tonnes of treated water sludge. Most of that is disposed of in landfill, costing more than $6 million each year, as well as causing severe environmental issues.”
Disposing one tonne of sludge in landfill releases approximately 29.4 tonnes of carbon dioxide emissions – much higher than cement production – and leaches aluminium into the soil and water, a risk factor for Alzheimer’s disease.
“We are confident this novel self-healing concrete based on advance composite technology will address issues of sewer pipe corrosion and sludge disposal in one hit,” Prof Zhuge says.
The project is being partially funded by a $501,504 Australian Research Council grant and involves researchers from the University of South Australia and University of Queensland.
More News and Articles
Apr 29, 2024
News
Minimising cultural impacts with trenchless
Through the benefits of trenchless technology, Yarra Valley Water is minimising impacts on the Upper Darebin Creek branch sewer project.
The project consists of building a 2.7km sewer pipe in Epping, …
Apr 26, 2024
News
Bothar’s cutting head innovation
The trenchless industry in Australia continues to grow and the need to provide customised solutions becomes vital for a leading subsurface contractor.
Recognising the need for advanced solutions to meet the growing …
Apr 24, 2024
News
Sustainable drainage solutions: German Start-up transforms urban water management.
Germany boasts a well-established infrastructure for managing rainwater and wastewater, yet many developing countries lack such systems. Addressing this gap, …
Apr 22, 2024
News
HDD tooling that gets the job done
Horizontal directional drilling is a dynamic process that constantly changes and adapts to suit a range of applications across utilities and infrastructure. Operators looking to get the most from their equipment …
Apr 19, 2024
News
WATCH: Overnight with SAERTEX-LINER H20 in São Paulo
Available through Pipe Core, high-quality liner SAERTEX-LINER H20 performed under pressure in São Paulo, Brazil.
Maintaining aging potable water pipe infrastructure is a constant challenge …
Apr 17, 2024
News
Immersive media provides wastewater experience in Denmark
An immersive media experience (IMX) may not be what most people want when they think about industrial wastewater, but that is exactly what visitors can expect when they visit a new installation …
Apr 15, 2024
News
Spotlight on gender diversity at Pipe Core
Since founding in 2008, Pipe Core’s team has grown across all areas of the business and is now in a position where there are more females than males across the organisation. Research published in Harvard …
Apr 12, 2024
News
New Wave of Startups Scale Innovation to Solve Global Water Challenges
Innovators from Around the World Join Xylem’s 2024 Accelerator Program to Deploy Breakthrough Innovations for Utilities and Industrial Users of Water
A new group of startups …
Apr 08, 2024
News
Integrated sustainable electricity and clean drinking water systems
Altitude Water and New Use Energy Solutions have partnered to create integrated, mobile solar-plus-water generation systems that produce sustainable electricity and clean drinking …
Apr 05, 2024
News
How to Evaluate Hydraulic Fracture Risk in HDD Design
The design of horizontal directional drill (HDD) installations often requires an evaluation of the potential for hydraulic fracture of the soil layers through which an HDD passes. Evaluating …
Apr 02, 2024
News
Historic Project Linking Rome and Vatican City Uses Advanced Technology and Local Knowledge to Keep Water Flowing
Relocation of Major Sewer Infrastructure Enables Construction of Pedestrian Link for 35 Million Visitors to the 2025 Jubilee
Water …
Mar 27, 2024
News
USU Study Looks at Water Main Break Rates in the U.S. and Canada
Report Highlights Correlation Between Material and Diameter
Utah State University (USU) has published new research on water main breaks in the United States and Canada, examining …
Contact
University of South Australia
Candy Gibson
Media contact
GPO Box 2471
SA 5001 Adelaide
Australia
Phone:
+61 (0) 434 605 142