In 2015, Gouda Wind Farm in South Africa commence operation with a generating capacity of 423GW hours of power. The generating capacity is expected to power about 200,000 homes a year.
Sika AG, a Switzerland based company with a head office in South Africa played a great role in constructing the wind farm. A number of the company’s products have been used in large quantities for the construction of the farm towers, such as SikaGrout-295 ZA (30 tons per tower), Sikadur-31 CF (one ton per tower) and Sealing Backing Cord (22km). As a result the company won the coveted Fulton Award for Innovation in Concrete.
Gouda Wind Farm is a joint venture owned partly by the South African company Aveng and Acciona Energia, a Spanish based renewable energy company. The wind farm is estimated to prevent the yearly production of 406 million metric tons of carbon dioxide through the modern clean energy generation technology as opposed to the ancient power generation.
Gouda wind farm towers are extremely high and therefore each tower is made up of three precast concrete segments joined on site on top of the other. Even so, each segment comprises of four sections that have been sealed and grouted together.
Horizontal joints on the tower segments have been sealed with Sika EVA Backing Strip. A semi-rigid, closed cell cross-linked construction foam. The foam is designed as a tough, flexible and resilient back-up support material for surface seals in load bearing joints, which can as well be used as a bedding seal under precast concrete panels. The foam product can as well be used to prevent loss of grout when joining precast concrete components.
The horizontal and vertical joints of the precast segments have been sealed with Sikadur-31 DW and Sikadur-31 CF. Both products are structural two-part adhesives, thixotropic, repair mortars based on a combination of epoxy resins and special fillers and are also moisture tolerant.
However, in order to provide a solid backing on the applied sealants, a Sealing Backing Cord has been placed into the expansion joints to regulate the depth of seal.
On the other hand, worn out concrete areas were repaired with Sika MonoTop-620 a cementitious, polymer modified, one-component pore sealer and leveling mortar containing silica fume. Sika MonoTop-620 provides excellent adhesion with good resistance to water and chloride penetration characterized with an adjustable consistency that can be applied by the wet spray method.
Derman Construction, completed the remaining Grouting of all vertical cavities using SikaGrout-295 ZA. The construction company used local trained labour that was offered by Jacques Reinecke and Anthony Webster who are Sika’s Technical Sales Consultant.
SikaGrout-295 ZA is described as a cement based grout, ultra-high strength, specifically designed for the renewable energy sector. The product can be used between concrete segments, filling cracks, gaps, large voids as well used under metal bases.
Additionally, a pumping trial became necessary to ensure that SikaGrout-295 ZA is capable of reaching the horizontal joints on the 100m high towers. Through the trial South African manufactured grout to Acciona Spain and it was successfully pumped to a height of 120m on an actual tower.
Not only did SikaGrout-295 ZA acquired the pumping trial approval, but it also scope an award for fatigue test certificate for durability, the ultimate test on a product that certify SikaGrout-295 ZA for worldwide use.
Gouda wind farm is not the only power project that the country has constructed. South Africa is one of several countries in Africa that have embraced renewable energy. In 2014 the country launched one of the biggest wind farm dabbed Jeffrey’s Bay wind farm. Recently it commissioned a mega offshore wind farm.
