Considering Concrete for your next Storage Tank Project? Consider the Facts...

There is a great misconception within the global marketplace about the durability, service life cost and capacity capability of bolted steel tanks when compared to both sectional and pre-cast concrete tanks for applications within the water, wastewater, and anaerobic digestion market sectors. 

When correctly specified and produced, concrete can be an excellent construction material providing long service in many conditions, however, the quality and durability of a concrete tank is dependent on many factors that are often difficult to control.

Consider the following:

PRE-STRESSED CONCRETE TANKS

  • Bioenergy plants provide a severe environment for concrete. As these tanks enter the first, second and third decade of service, the effects of years of unprotected exposure are apparent with cracks, spalls, and leaks.

  • The introduction of reinforcing steel created a problem affecting the durability of concrete. As rebar corrodes, concrete cracks and spalls reducing structural integrity AND allowing elements to enter into the concrete increasing the deterioration. Additionally, rust forming on rebar increases the volume (result = expansion) of the steel creating large tensile forces. Concrete cannot withstand tensile stress and it cracks to relieve the pressures.
  • A damaged concrete tank would have a high likelihood of having to be torn down and replaced. Nozzles can sometimes be added In the field, but this Is not an easy process as it interferes with the wire windings and additional rebar has not been added to accept the hole.
  • Concrete tanks require large staging areas so that the tank can be fabricated and then craned Into place. Depending on the site conditions, this can be a very expensive additional cost for a project sometimes requiring clearing large areas of trees or forests and leveling areas for laydown.
  • Concrete tanks, especially wire wound, are manufactured on site resulting in very labor heavy cost.
  • If you want to maintain the appearance of concrete, you must provide a coating on the tank exterior and while it is not mandatory to replace that coating, if you want the concrete tank to maintain a nice appearance, this becomes a future recurring maintenance cost.
  • Not NSF61 Compliant.

EA TANKS BOLTED STORAGE TANKS

  • EA Tanks have a lifetime of flexibility. If for some reason the tank is damaged, the individual panels can easily, quickly and economically be replaced. If an additional nozzle is needed in the future, it can easily be added in the field. 

  • EA Tanks are constructed in 1/3 of the time it takes to build a pre-stressed concrete tank. Because the steel is manufactured In a plant. Once the tank hits the site, it can easily be constructed within a short period of time. 
  • EA Tanks sustain their appearance. Because the glass does not chalk, fade or discolor, the tanks will maintain their beauty. Concrete tanks will begin to discolor and look unsightly almost immediately. 
  • EA Tanks are easily and economically expandable. Simply design the foundation for expected future loading (This is usually a very inconsequential dollar amount). When additional capacity is required, we go in, unbolt the bottom ring, jack the tank up and add the required number of additional rings (vertical expansion) to get to the desired capacity. 
  • EA Tanks are the most vandalism friendly tanks on the market. Graffiti being the largest potential for vandalism. With a glass tank, it simply washes off with a solvent. Concrete tanks would require a coating applied over the top. 
  • EA Tanks require minimal site work. Because the tanks are manufactured In a plant, all that is required is room around the tank to maneuver the panels into place. We ask for a 10’ area around the tank diameter, but it is possible to build In less than 24” if needed and we have done this. Minimal site work can bring the overall project cost down significantly.

There are too many things in their walls that can have issues. Once concrete is compromised, windings are exposed and structural corrosion is an issue. One bend in the rebar means less covering of shotcrete and more potential for problems. Biofilm is becoming a major source of concern in storage tanks, and concrete’s rough surface (pits and crevices) attract Biofilm more than any other tank surface. - Hunt Engineering

Concrete works at its optimum and is at its strongest when it is in compression, therefore efficiently carrying the compressional load. A base is subjected to significant loads from the stored liquid and, when used in this way, concrete is the best solution. 

What many people do not appreciate is that while concrete is very efficient when subjected to compressional loads, it is not as strong in tension. A structure wall, whether square or cylindrical, holding a liquid is placed under significant tension from the internal hydraulic load. It is the reinforcing bars within concrete that give the structure its tensile strength. Concrete is susceptible to cracking which is the reason why so many concrete tanks show signs of visible leaks from the vertical walls and require substantial remedial maintenance. 

"Partially buried concrete tanks are the worst. Concrete tanks should never be partially buried. The temperature differential between the buried and above ground parts create condensation on the underside of the roof which will cause damage." - Metcalf and Eddy Engineering

Are you still considering a concrete tank for your next project? Read on... 

EA Tanks’ glass manufacturer uses high-quality grades of sheet steel which meet or exceed the requirements of relevant tank design standards and applicable International Standards e.g. AWWA D103-09, EN 10025, EN ISO 28765:2016, EN 10149 and ASTM A1011. The modular sheets are bolted together by a series of vertical and horizontal joints which are sealed using a purpose designed sealant. 

Steel performs much better in tension due to the fact that it is a more predictable material which makes EA Tanks systems an economical alternative to conventional concrete tanks. EA Tanks structures incorporate the best properties of both materials, the steel tank, and the concrete base. 

Why else should I consider the EA Tanks product? 

EA Tanks not only offer the consistent quality of a factory-applied coating but also offer other significant structural benefits that enable customers to take advantage of our cost-effective engineered designs. This ensures end users are provided with a high-performance structure with minimal maintenance costs.

Contact your local EA Tanks Salesperson today for more information!