Construction World May 2017

The problem at the reservoir was an excessively wide wall-to-floor joint measuring over 75 mm in width. In consultation with Sika’s Jacobus Pretorius, engineers from Ekurhuleni Water specified the effective Sikadur-Combiflex SG System for the project. Designed for use in construction, expansion and connection joints, the Sikadur-Combiflex SG System consists of a modified, flexible Polyolefin (FPO) waterproofing tape bonded to Sikadur-31 DW, a moisture-tolerant, structural two-part adhesive and repair mortar based on a combination of epoxy resins and special fillers. Both products have international approval for contact with drinking water and can be applied to both dry and damp Closing the gap A high performance joint sealing system supplied by Sika has solved a problem at an ageing reservoir in Primrose, Gauteng. Constructed in 1985, the 40 M ℓ Ekurhuleni Reservoir is just one of dozens of reservoirs supplying potable water to the people on the East Rand.

concrete surfaces. Sikadur-31 DW is a high strength, thixotropic adhesive that hardens without shrinkage and is impermeable to liquids and water vapour. Requiring no primer, it is easy to mix and apply, and provides excellent adhesion to most construction materials. Extremely flexible and performing well in a wide range of temperatures, the Sikadur- Combiflex SG System is suitable for use in many difficult situations. When fixed to a joint, the system allows for irregular and high movement in more than one direction, while still maintaining a high quality seal. It is ideal for use in tunnels, culverts, hydro- electric power plants, all water retaining structures including seawater and even sewage treatment plants.

Aquatan Lining Systems, experts in the geosynthetic installations, was awarded the contract and used a total of 350 m of Sikadur-Combiflex tape (450 mm x 2 mm) to seal the gaping joint. The waterproofing tape is supplied in 25 m rolls of various widths, either 1 mm or 2 mm thick. Although 30 years old, this was the first refurbishment project on the Ekurhuleni Reservoir and forms part of the Ekurhuleni Metropolitan Municipality’s water infrastructure upgrade plan, which also includes the construction of 20 new reservoirs. Thanks to Sika’s exceptional joint sealing system, the Ekurhuleni Reservoir was saved the ignominy of being decommissioned, as has been the fate of many other ageing reservoirs. 

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CONSTRUCTION WORLD MAY 2017