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Self-Healing Concrete Sewer Systems
2025_12
New innovative and sustainable capsule offers an effective, fast solution to improve concrete durability in aggressive sewer environments compared to traditional methods.
In sewer systems, microbial activity generates elevated levels of CO₂, which accelerates the corrosion of concrete sewer pipes.
A team of researchers at the University of South Australia (UniSA), led by Professor Yan Zhuge including PhD candidate Hossein Sanaei Ataabadi, are enhancing concrete durability by improving its self-healing capability.
The team engineered capsules from water treatment sludge combined with calcium hydroxide and expansive agents and incorporated them into cement mixtures. The capsules triggered crack closure through carbonation and chemical reactions, closing cracks over 90% by 28 days and significantly improving water tightness, demonstrating strengthened performance for sewer environments.
With its advanced imaging technology and additive manufacturing facilities located at UniSA’s Mawson Lakes campus, the South Australian node of the Australian National Fabrication Facility (ANFF-SA) provided fabrication and key characterisation support during development.
Hossein said “ANFF-SA supported this project by providing access to advanced equipment and technical expertise essential for testing and analysis.”
ANFF-SA created the 3D printed spherical silicon moulds that assisted capsule creation. Imaging equipment used included ANFF-SA’s Olympus OLS5000 laser microscope to monitor changes in the capsules surfaces after exposure to water and to assess any dissolution of the capsule’s core material over time. Also ANFF-SA’s micro-XCTZeiss Xradia 400 was vital for providing a non-destructive evaluation of the internal structure cementitious samples containing self-healing capsules.
Hossein said “ANFF-SA’s Micro-Computed Tomography (Micro-XCT) facility, provided essential scans that allowed us to visualise microcracks, capsule distribution, and healing progression over time with high spatial resolution.”
ANFF-SA assisted with optimising scan parameters and reconstructing 3D models of samples with ANFF-SA Characterisation Specialist, Dr Iliana Delcheva, having played a key role offering expert guidance in experimental setup, data interpretation, and software analysis.
Hossein said “Iliana’s assistance ensured accurate and reliable results which significantly contributed to the efficiency and precision of the testing process, particularly in dealing with challenges like material density and contrast.”
Deterioration in concrete sewer pipelines is an urgent challenge which this study provides an effective solution combining the dual benefit of environmental waste valorisation and infrastructure protection.
Hossein said “the capsules autonomously seal microcracks and strengthen the cement matrix, ultimately reducing maintenance costs, extending infrastructure life, and minimising CO₂ emissions from landfilled sludge.”
Further research and optimisation of the self-healing capsule system is needed which Hossein highlights that ANFF-SA facilities and expertise will be essential for future R&D, “their infrastructure not only accelerates development timelines but also enables us to validate our designs with high-resolution, non-destructive analysis techniques that would otherwise be unavailable. Particularly in terms of capsule miniaturisation, shell composition, and performance in more complex environments—access to ANFF-SA’s advanced imaging tools will be critical.”
ANFF-SA is a world-class micro and nanofabrication facility providing open access to cutting-edge equipment housed in state-of-the-art facilities with support from world-leading experts. If you require support or assistance with your project or research, contact us on 08 8302 5226.