Installation of concrete protection and waterproofing on Kusile Power Station’s chimney stacks

BKV Holdings was appointed by Karenna Concor Joint venture (JV), comprising Concor and Grinaker-LTA (now Aveng Grinaker-LTA), to install concrete protection/waterproofing, as well as flue bellows on the 211m level of the North and South Chimney stacks at Eskom’s Kusile Power Station in Mpumalanga.

Importantly, the coating materials that were used to protect the concrete and render it water tight had to be flexible and able to withstand the corrosive fallout from the flue gases.

The project also entailed undertaking major concrete repairs to the cracked 211mm screed before installing the bellows, which act as a weather curtain around the flues of each canister.

We devised a method that would allow for the natural movement of the existing cracks and provide flexible protection to the concrete surface.

As accessing the 211 m level of the chimney stack was only possible using a bucket excavator, it took up to 10min to transport all equipment and materials to the working area.

Our team also had to consider the chemical fallout from the flues as a major component of work had to be undertaken while the flue stacks were operational.

BKV Holdings prides itself in its unwavering equipment to safety and there was not a single incident on site during the entire duration of the project.

Moreover, all of our work was successfully signed off by Karenna Concor JV’s own engineers and quality inspectors.

Our sophisticated solution entailed:

  • Grinding the entire floor area to prepare the surface;
  • Using Epoxerite E151 Mastic for the concrete repairs;
  • Applying NUI Ultracote 520-020 as the primer;
  • Using NUI Polybron 350-012FC as the base coat; and
  • Applying NUI Ultracote 882P029 as the corrosion coat.

We used the following equipment on this project:

  • A concrete grinding machine; and
  • Various small hand and power tools.