The reinforced concrete Acid Tank bund contained 3no. large diameter acid containment tanks with diameters ranging from 14.6m – 16.3m and measuring between 9.4m to 9.7m high. The site also contained 1no medium sized tank Ø 9m x 10m high and 2no smaller tanks of Ø3.5m x 5.0 high and Ø3.5m x 5.3m high. Several plinths were also in place which did not support any tanks. The Acid Tank Farm is enclosed by a reinforced concrete bund wall and reinforced concrete floor slabs set at varying levels. The 200mm wide bund wall varies in height from approximately 1.5m high to 1.9m. A drainage channel located at the base of the internal perimeter bund walls appeared to drain to several sumps.
The concrete was suffering from extensive acid attack resulting in leakage and widespread deterioration. The site was not draining leading to advanced deterioration due to acid contaminated water.
Scope of works
- Demolition of a large steel acid storage tank.
- Hydrodemoltion to remove concrete subjected to acid attack within a large, reinforced concrete acid bund.
- Pile and pile cap design and construction for four new tank bases.
- Bund floor levels designed to ensure stormwater and acid spillage is channelled to sumps to mitigate the destructive acid attack associated with historic pooling of contaminated water. Equilibrant designed the new bund floor levels through precise topographical survey and 3D modelling.
- Extensive concrete repairs and provision of an acid resistant coating.
Innovation
Equilibrant combined inhouse knowledge of specialist surveying techniques, structural non-destructive testing and materials testing with procurement and project management expertise to deliver a complex refurbishment project. The innovative use of the “N4CE” software allowed the volumetric capacity checks to be completed to a high level of accuracy. The software was also used to design new floor levels within the bunded area to ensure optimal drainage falls were incorporated for durability which resulted in reducing bund capacity. A final volumetric capacity based on designed floor levels confirmed the capacity of the remedial works design was compliant with the strict standards required by the Petrochemical industry.
