Water treatment structures that are damaged with cracks and other surface deterioration are in danger of both leakage and outside contamination hazards. Choosing the right protective coating product for these concrete assets is crucial and plays a vital role in containing and protecting the treated water and maximises the service lifespan of the structure. 

Protecting the structure

Structurally, the integrity of a water treatment tank is largely dependent on the steel reinforcement, which is protected from external forces – such as the water in the tank – by the surrounding concrete. Should the concrete become compromised with cracks, joint-failure or chemical attacks, this could allow water to reach the steel structure, causing rust and corrosion. This not only weakens the integrity of the tank, but can also contaminate the water stored inside. In the worst case scenario this could lead to total structural failure – the consequences of which are costly. 

Reversing concrete’s natural porosity

As concrete is naturally porous, water will be able to permeate it if it remains unprotected,  causing defects such as cracks, leaks and other surface deterioration that eventually penetrates the steel reinforcement. A structural concrete repair coating such as Hychem’s VELOSIT RM204 can reverse the damage done to the concrete while prolonging the life and integrity of the structure without the need for costly replacement.

VELOSIT in action

The Sunbury Water Treatment Plant provides around 800ML of Class B water per year. The water is used to irrigate many important local assets such as sporting fields, the golf course and wineries, and for other agricultural uses in Sunbury and Diggers Rest. Hychem worked with Western Water (now Greater Western Water) and a consulting engineer to reinstate nine water treatment tanks over approximately 2000m² to their design thickness of over 40mm.

For the project, a combination of VELOSIT high strength mortar and Geocast were wet/dry spray applied at a thickness of 40mm before being coated with VELOSIT WP120 sealant at a thickness of 2mm. Overall, 180 pallets of these Hychem materials were delivered and applied on-site.

The Senior Technical Consultant – Infrastructure AUS/NZ at Hychem, Colin Murphy, said, “The VELOSIT mortar system is ideal to reinstate water treatment tanks as it is a high-strength mortar formulated especially for repair and restoration.

“VELOSIT RM 204 is the result of many years of in-field testing and research. It can be used to fill large voids or build up larger cross-sections up to 100mm.”

Reinstatement of the water treatment tanks will directly contribute to reduced maintenance costs, prolonged life of the structure and, of course, protect the future of many of Sunbury’s important local assets that rely on the treated water.