Problem:

4 mega RCC tailing thickener tanks of a mining company, having surface area of 25,000sqft eachwere observed with issues likedeterioration of RCC supporting structure because of corrosion, pitting of concrete surface and leakages through expansion joints.

Diagnosis:

The slurry stored inside the sedimentation tank was acidic. Due to continuous drippingofacidic slurry on RCC elements, progressive corrosion damage was observed. The main source of leakage was the expansion joint. Eventually over time, the inner protective coating of the tank was giving away, exposing the reinforcements inside the surface of the tank to acidic slurry.

Solution:

• Expansion joint cleaned, backer rods placed, water-tight sealant applied, taped, closed with SS panel and epoxy coated the entire interior surface. Protective coat of acid resistant paint was applied on entire surface to protect against future exposure.
• Rebars exposed by chipping, cleaned and cathodic protection applied using cannodes and capulets.
• Pressure grout & polymer modified mortar on RCC
• Weaker columns strengthened by GFRP wraps