Sika’s repair and rehabilitation products were specified for the Driefontein Wastewater Treatment Works expansion project.

Sika’s repair and rehabilitation products played a key role in the expansion of the Driefontein Wastewater Treatment Works, which included restoration to walling and concrete protection on clarifiers and pump stations.

The concrete walls were primed with SikaTop-Armatec 110 EpoCem, a cement-based, epoxy-modified, anti-corrosion coating and bonding agent that acts as an effective barrier to water and chlorides, while Sika Rep LW, a non-sag, cement-based, multi-purpose patching and repair mortar was used for necessary cosmetic and structural repairs.

For steel reinforcement protection, Sika MonoTop-610, which meets the ZTV-SIB requirements for corrosion protection, was applied. It forms a bonding-slurry for Sika MonoTop-615 HB, a high-build repair and reprofiling mortar especially suited for vertical and overhead applications, which was used on the sections of walling requiring thick-layer concrete repairs.

As part of the concrete protection on the plant’s clarifiers and pump stations, three solvent-free Sika products were selected. Firstly, Sikagard-720 EpoCem, a three-part, epoxy-modified, fine-textured mortar for levelling and finishing of concrete, particularly in aggressive chemical environments, was applied. It is impervious to liquids, but permeable to water vapour, and forms an excellent bond to either green or hardened concrete.

After a minimum waiting period, Sikafloor-156 ZA, a two-part, low viscosity, epoxy resin was applied. The final protection layer was achieved with applications of Sikagard-63 N, an abrasion-resistant, two-part, liquid-proof epoxy resin coating.

Finally, those areas subjected to aggressive chemical attack were protected with a laminate system created by combining Sikagard-63 N with glass-fibre membrane.

While time constraints, difficult working conditions in confined spaces and weather delays put contractors under severe pressure, the ease of mixing and application of Sika’s products helped to alleviate the situation.

Sika
Tel: 031 792 5600
Website: www.sika.co.za