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.