Tank Service Life Estimate
The tank, classified as an American Water Works Association (AWWA) D-110 Type I tank, is a strand-wound circular, prestressed concrete water tank with cast-in-place concrete tank walls clad in shotcrete. DN Tanks wanted to evaluate if the tank could achieve an estimated 100 year service life at the proposed location. SGH performed service life modeling of the tank intended to store potable water.
The proposed tank would be exposed to the stored water on the interior and the exterior would be subject to weather and wind-borne salts from the nearby sea. SGH worked with SIMCO, the developer of STADIUM® service-life-modeling software, to customize the software in order to analyze the two-way flow of moisture and chlorides.
We provided the parameters to SIMCO for input into their developer-only version. We then validated their results using an ionic diffusion model to estimate the time to damage from corrosion of the embedded steel reinforcement.
Based on the assumed environment and porosity of the concrete, we were able to demonstrate that the Type I tank would achieve an estimated 100 year service life and that the actual usable service life would likely exceed that benchmark.