THE PROBLEM
The fat bund had been identified as a risk during an environmental audit and a suitable bund lining being required to reduce this risk.
Fat Bund Lining, Cumbria
THE SOLUTION
We proposed the application of a crack bridging, yet highly chemical resistance bund lining in the form of Remmers Epoxy WHG.
A major challenge was that the works had to be completed during winter months which would mean that the climatic conditions with regard to relative humidity, dew point and ambient temperatures would not be suitable for bund lining application.
Therefore working with our client a scaffold encapsulation and indirect oil fired heating with dehumidification was installed prior to works commencing.
Prior to our arrival on site the bund receive a deep clean using steam cleaners and emulsifying degreasers to prevent the moving and spreading of fat contamination during the preparation phase of the works.
All concrete surfaces were prepared by method of vacuum controlled diamond grinding to remove surface contamination and laitance.
The areas of the steel tank bases which were to be coated were prepared to ST2 as per ISO8501-1 by method of bristle blasting.
This was followed by the priming of these areas using Corroless EPF – a rust stabilising epoxy primer which contains a mined pigment that converts corrosion present to stable iron oxides.
Once all preparation works had been completed all surfaces to be treated were vacuumed clean to prevent dust disrupting the bond of the bund lining.
To the block walls a cementitious fairing coat in the form of Remmers Sulfatex grout was applied by method of slurry brush to provide a regular surface free from blow holes to apply the bund lining to. Blow holes and surface porosity cannot be filled with coatings alone and single blow hole is a point of bund lining failure.
As per best bund lining practice a cove detail was installed at the floor wall interface to isolate the most likely point of potential movement from the bund lining. This serves as an elongation multiplier by spreading any potential movement over a greater area and thus giving greater elongation potential to the applied bund lining.
All cementitious materials were allowed to hydrate with minimal heating and without the use of dehumidifiers to prevent cracking from rapid drying out. The hydration was tested and recorded as part of standard bund lining quality assurance.
Prior to and during coating works the climatic conditions were tested and recorded to ensure compliance with the manufacturers recommendations.
All surfaces were primed using Remmers Epoxy MT100 damp tolerant epoxy primer, which can be applied to substrates with a moisture content of up to 6%.
Once cured the new bund lining was tested for porosity using a DC holiday spark tester. In bunds containing aggressive chemicals a single pin hole is a point of bund lining failure. Any defects identified were marked with chalk prior to touching in using the same material applied by brush.
