THE PROBLEM
The concrete sump in the vegetable processing facility was leaking into the production area below, causing damage to the roof coatings beneath and presenting a product contamination risk. The concrete was also showing severely exposed aggregates as a result of the acidic cleaning chemicals used.
THE SOLUTION
We proposed the application of a seamless spray applied polyurea lining to resolve the water egress issues.
Preparing the concrete
Initially all surfaces to be coated were prepared by method of vacuum controlled diamond grinding to remove loose aggregates and lessen the surface profile.
A cementitious grout coat was applied to the bund walls to fill blow holes and porosity. A polyurethane repair mortar was applied to the bund floor to fill the profile. This was chosen over a cementitious material due to the lack of a curing period which would have presented a challenge given the short bund lining duration over the Christmas shutdown.
Applying the Primer
To ensure excellent adhesion of the new polyurea lining an epoxy primer was applied throughout including to the galvanised and stainless steel supports which had previously been abraded. The primer selected is specifically designed to adhere to difficult substrates such as these.
To isolate the polyurea lining from potential points of movement and aid application all nuts, bolts and corners were detailed using a polyurethane jointing compound.
Once cured SPI HT100F UB was spray applied to a thickness of 2mm throughout followed by spark testing to check for pin holing.
Slip Resistant Seal Coat
To enable the client to safely clean the area a slip resistant seal coat of SPI Staingard Rapide was applied incorporating rounded polymer beads. Ton ensure adhesion this had to be applied within the polyurea coatings 8 hour overcoat window.
The rapid cure time of this material allowed the bund to be returned to product two days later.
