Engineers are rethinking the soil surrounding buried pipelines in a bid to help reduce Australia's billion-dollar annual corrosion problem and extend the lifespan of critical infrastructure.
Monash research, published in Geotechnical and Geological Engineering, explores how specially designed backfill materials could be used as an active corrosion protection system rather than simply providing mechanical support.
Australia has an estimated 260,000 kilometres of pipelines, with around 80 per cent buried underground and made from metallic materials vulnerable to corrosion.
Corrosion-related failures are estimated to cost up to $1 billion annually through repairs, maintenance, water loss and infrastructure replacement.
The review paper brings together research from geotechnical engineering and corrosion science to examine how factors including moisture, soil acidity, salt concentration, electrical resistivity and compaction influence the corrosion of buried ductile iron pipelines.
Lead author and Monash PhD candidate Thisara Senarathna said current industry approaches typically focus on the structural performance of backfill materials, despite the surrounding soil environment playing a major role in corrosion rates.
"Protective coatings and cathodic protection systems remain important, but their effectiveness is strongly influenced by the surrounding soil conditions," Mr Senarathna said.
"Our work shows backfill should be treated as part of the corrosion protection strategy itself, not just material used to support the pipe."
The broader project is investigating new resistive backfill materials, construction methods and modelling techniques aimed at minimising corrosion across entire pipeline networks, including interference effects between adjacent buried pipes in congested urban environments.
Researchers say the approach could provide a more practical and low-cost pathway for improving infrastructure longevity while reducing maintenance demands and the carbon footprint associated with replacing ageing underground assets.
Co-author Professor Jayantha Kodikara, Director of the ARC Smart Pavements Hub at Monash, said the findings support a shift toward performance-based backfill design standards.
"Corrosion is often treated as a separate issue from geotechnical engineering, but these systems are deeply interconnected," Professor Kodikara said.
"This research highlights the need for more integrated infrastructure design approaches that consider both structural performance and long-term corrosion resistance."
The study also includes insights from Australian industry surveys examining current maintenance challenges and corrosion management practices across buried pipeline systems.
Read the research paper: https://doi.org/10.1007/s10706-026-03692-8
