Innovative lining and coating solutions for critical water infrastructure

With the Australian Government set to invest $2 billion in water infrastructure over the next 10 years, most of which will be undertaken in partnership with the states and territories, there is an opportunity to demonstrate how new product innovations can help protect the structural integrity of newly built infrastructure and help extend the longevity of existing assets.

Chemicals commonly used in water treatment and sewerage plants can quickly degrade concrete linings. When this occurs, the chemicals quickly start eating away at the concrete fines which in turn, speeds up the ageing process. When constructing or maintaining water infrastructure with concrete surfaces, repairing the structure using protective coatings, such as polyurea, can enhance the asset’s lifespan by delivering long-term protection.

However, the challenge when considering re-lining solutions for water infrastructure is ensuring the products are appropriate for the task. Water stopping measures not only need to be impervious to water; they also need to have specific anti-corrosive properties that can withstand various chemicals commonly used in sewerage treatment plants and water recycling tanks. The different chemical compositions can determine the type of lining the surfaces are coated with and how well it will bond to the substrate.

Mainmark has extensive experience working with contractors, councils and civil engineers to assist them in selecting the right long-term asset preservation solutions for major water projects which can incorporate water treatment plants, pipes, tanks, reservoirs, and sewerage pits. For example, Mainmark worked closely with Glen Innes Severn Council to re-line the filter ponds and clarifier tank at Glen Innes Water Treatment Plant in Northern NSW.  Mainmark applied a pure polyurea coating to the three filter ponds and clarifier tank which were first primed with a two-part epoxy solution that is specifically designed to improve the adhesion of the polyurea. The new linings are expected to extend the life of the asset for at least another 20 years.

Another successful re-lining project was undertaken to rejuvenate the external and internal surfaces of an above ground drinking water reservoir in Far North Queensland where active leaks had been detected. The huge concrete structure was 34m in diameter and 6m high, with a storage capacity of 4.55 megalitres. Mainmark applied a pure polyurea coating to the internal space and then coated the external surface with a high grade, graffiti proof, epoxy coating that was selected for its ability to withstand very harsh environments.

Selecting the right solution

The most important decision when lining water infrastructure assets is selecting the right water stop material that is fit for purpose.  What the structure is made of, and the chemicals that it is exposed to, informs the appropriate product that will withstand its environment. If the wrong product is selected, the remediation work is likely to fail in the short term.

Surface preparation is also extremely important. Analysing the bond between the original substrate and coating will identify certain weaknesses, however, this crucial first step is often overlooked by many engineers and contractors, who find themselves dealing with unnecessary problems, such as water leaks or delamination, as the project progresses or after its completion.

Water ingress leads to ground stabilisation issues

For large pipes and below ground tanks, water ingress around the structure can often lead to ground movement and cracking. Water permeation then creates weak ground that will accelerate structural degradation.

For infrastructure reinforced with steel, the presence of water will also start the carbonisation process, where carbon dioxide enters the concrete and causes a chemical reaction that results in concrete cancer. This can have devastating consequences on water infrastructure and water quality.

Mainmark’s range of specialised resins, coatings and gels can help engineers minimise the risk of water ingress by forming impenetrable barriers for specific substrates. The extremely hard-wearing range of water stop solutions are non-invasive, easy to apply and cost effective.

After recent reports of major infrastructure cost blowouts, the spotlight will turn to contractors in an effort to contain costs. Becoming smarter in the way products are selected, and being more accountable for long-term deliverables, will become increasingly important for asset owners who will seek alternative solutions that can help save money and improve productivity. In many cases, they will also seek to remediate rather than replace ageing infrastructure.

New products and solutions such as Mainmark’s range of specialised coatings, resins and gels, deliver time and cost efficiencies while providing long-term outcomes that are proven to increase asset longevity.