Concrete water reservoirs are critical community assets.
While they may vary greatly in size, style, and design, they all share the common requirement to provide secure and hygienic storage of potable water coupled with straightforward periodic inspection and cleaning.
Although often overlooked, the potable water environment can be a complex one, with a variety of physical, chemical, electrochemical, biological and maintenance issues that need to be considered when selecting an internal lining system.
Unique proven lining technologies can address these issues and ultimately, provide long lasting, leak-proof, internal protection.

Why internally line concrete water reservoirs?

Physical considerations:

• All concrete cracks
• Concrete is not watertight
• Concrete mix design variations affect concrete durability
• Steel in concrete corrosion is common

Chemical considerations:

• Increasing rainwater acidity levels due to rising CO2 levels, acid rain, unstable weather conditions
  eg pH = 4.5, Sydney summer – Acidity of summer rainfall in Sydney. Ayers & Gillett. ‘The Urban Atmosphere —Sydney, a Case Study’
• Acidic solutions attack concrete – the lower the pH, the faster the action
• Cement paste is dissolved & aggregate exposed
• Leaching of soluble components in concrete
  eg “Leachability and Concrete” – Portland Cement Association
• Steel in concrete corrosion potential increases as pH drops
  eg “Corrosion of Reinforcing bars in concrete” – Hansson, Poursaee, Jaffer

Electrochemical considerations:

• Salts in solution allow stray currents to initiate anode / cathode decomposition reactions on steel in concrete
• Corrosion cells lead to rust which expands and spalls concrete

Biological considerations:

• Concrete is not naturally potable water safe – requires component pre-testing
• Porous nature of concrete allows mould to become deep seated
• Porous concrete is not naturally anti-bacterial

Maintenance considerations:

• Uncoated, wet concrete will not reflect introduced light
• Reduced maintenance costs … far easier to inspect and clean

What is required in a durable internal lining?

• Extreme water resistance
• Potable water approved / will not support bacterial growth
• Excellent adhesion to prepared concrete
• High mechanical & surface hardness (reduced damage potential)
• Suitable for declining pH => long term acid resistance
• Repairable after structural damage
• Chemically inert
• Biologically inert
• Electrically insulative
• No residual potential chemical reactivity
• Light in colour – good reflectivity to aid inspection

Interested?

Talk to EpiMax. We are on your wavelength.