Committed to environmental care, Sika’s renowned solutions were recently specified in the construction of the newest drainage process at Swartkops River by SRK Consulting, on behalf of their client, Power Construction. The Motherwell location, in Nelson Mandela Bay, is a rapidly growing yet underdeveloped urban settlement. The area was allocated primarily for the relocation of squatter families in an informal residential area north of Swartkops River. The Motherwell storm-water canal has its outlet into the Swartkops River and as a result the open system has adversely affected the quality of the water, which consequently has detrimental effects on the health of the community. In an effort to reduce pollution, a small portion of water from the canal is being diverted into the filtering procedure, by means of a HDPE pipe, from the heavily contaminated river. This water then runs down through the primary water ‘cell’, and into a series of smaller ‘cells’ before eventually flowing back into the Swartkops River.

Two of the high-quality products specified on site were from the SikaSwell swellable profiles and sealants range, of extremely cost effective hydrophilic joint sealing systems. The products are primarily used for sealing concrete joints against low to medium water pressure, or to provide additional protection and security for other waterproofing systems. SikaSwell S-2 is easy to apply, permanently water resistant, and has good adhesion to various substrates, making it suitable for many different project requirements. On the Motherwell site, this sealant was used to bond the SikaSwell-P 2507 H which is ideal for application on materials such as; concrete structures, precase elements and tunnel segments. In addition, it offers rapid curing and installation times.

Cemflex, a universal waterproofer and bonding agent, was specified for use on the footings of the structure. This non-toxic acrylic-based emulsion improves water resistance and is ideal for both submerged and subterranean waterproofing. Sikaflex-11 FC⁺, used to seal the expansion joints of the constructed system, is a polyurethane based, moisture curing, elastic joint sealant and multipurpose adhesive. As a joint sealant, it has very good adhesion, bubble-free curing, as well as good weather and aging resistance. Three-part SikaTop Armatec-110 EpoCem, a cement-based,

epoxy-modified, anti-corrosion coating and bonding agent was specified to ensure a high degree of mechanical strength. This product has good adhesion to steel and concrete, contains corrosion inhibitors, and was crucial in this project as it serves as an effective barrier against the penetration of water and chlorides. Cementitious, one-component Sika MonoTop-620, was developed as a pore sealer and leveling mortar. Applied by trowel, the product was used on site to patch repairs on the structure. The final product used in this eight month long project was Sika MonoTop-612, a cementitious, polymer modified, high strength mortar containing silica fume and synthetic fibre reinforcement. The surfaces on site received this repair mortar treatment to ensure that the structure would remain in the best possible condition for years to come.

The existing system, before the construction of this new drainage solution, solved a meagre 10% of the pollution problem. Depending on the success of this new system, it is envisaged that a similar structure will be built on the other side of the canal. With the high strength and uncompromising quality of Sika products on site, it is probable that this experimental project will soon be repeated to increase water cleanliness in other polluted areas.