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DECEMBER • 2016
Construction
WORLD
36
Specialist Contractors or Suppliers
B
Project information
• Company entering: Sika
• Client: ACCIONA
• Main contractor: Lowind/DD Materials
GOUDA WIND FARM
For construction of these 100-metre tall towers vast quantities of
Sika products were supplied. Jacques Reinecke, head of renewable
energy for Sika SA, spearheaded the specification and installation
of the Sika product and instructed on-site training.
Sika products used in large quantities for the construction of
the towers included Sikadur-31 CF (one ton per tower), Sealing
Backing Cord (22 km) and SikaGrout-295 ZA (30 tons per tower).
Each column is comprised of four precast segments that were
sealed and grouted together onsite. Due to the extreme height of
the towers, each tower comprises four precast concrete columns
of 20 m in height, joined on site, one on top of the other. A final
column carrying the nacelle brings each of the 46 towers to a
height of 100 m each.
Horizontal joints on the tower segments were sealed with
Sika EVA Backing Strip. This semi-rigid, closed cell cross-linked
construction foam is designed as a tough, flexible and resilient
back-up support material for surface seals in load bearing joints.
It can also be used as a bedding seal under precast concrete
panels and to prevent loss of grout when joining precast
concrete components.
Once joined together, the vertical and horizontal joints of
the precast segments were sealed with Sikadur-31 CF and
Sikadur-31 DW. Both products are moisture tolerant, thixotropic,
structural two-part adhesives and repair mortars based on a
combination of epoxy resins and special fillers. Easy to mix and
apply, they are suitable for both dry and damp concrete surfaces
and harden without shrinkage. They provide high initial and
ultimate mechanical strength and are impermeable to liquids and
water vapour. Sealing Backing Cord was placed into the expansion
joints to regulate the depth of seal and to provide a solid backing
onto which the sealants were placed.
Mould imperfections of the newly produced towers were
repaired with Sika MonoTop-620, a cementitious, polymer modified,
one-component pore sealer and leveling mortar containing silica
fume. With an adjustable consistency, it can be applied by the
wet spray method and provides excellent adhesion with good
resistance to water and chloride penetration.
DD Materials, who used local labour trained by Sika’s Jacques
Reinecke and Anthony Webster, completed the grouting of all
vertical cavities using SikaGrout-295 ZA. SikaGrout-295 ZA
is a one-component, ultra-high strength, cement based grout,
specifically designed for use in the renewable energy field, under
metal bases, between concrete segments and to fill cracks, gaps
and large voids. Due to its good flow properties this is a pumpable
grout that provides rapid strength development.
During the project SikaGrout-295 ZA was sent for fatigue
testing and Sika is proud to announce the product is now certified
for durability.
DD Materials completed the grouting of all vertical cavities
using a local labour team of 24 skilled and semi-skilled applicators,
trained by Jacques Reinecke, Head of Renewable Energy, Sika SA,
and Anthony Webster, Sika Technical Sales Consultant. In addition
to this training there was training on concrete repair, waterproofing
and epoxy applications.
The entire project was instrumental in creating an average
of 400 jobs, with hikes of up to 800 employees during the
construction phase.
In September 2015, the Gouda Wind Farm, owned in partnership
by the South African company, Aveng, and the Spanish renewable
energy company, Acciona, commenced operations with a
generating capability of 423 gigawatt hours of electricity through
which 200 000 homes will be powered per annum. It is estimated
that the clean energy generated by this wind farm will prevent the
emission of 406 million metric tons of carbon dioxide per year.
One of the client’s primary requirements was a high local
content on products. 100% of all Sika SA products used in the
Gouda Wind Farm project were locally produced.
Sika products, tried and tested for their reliability and
endurance, have been used in this project, adding to the
sustainability value of Gouda Wind Farm.
All PPE requirements were adhered to onsite on a daily basis
and each employee underwent induction before commencing work.
Acciona has a well-established and certified corporate
Integrated Management System (IMS) incorporating Quality (ISO
9001), Environment (ISO 14001) and Health & Safety (OHSAS
18001). This corporate IMS has been extended to each of
Acciona’s main business lines, including AE.
Corporate IMS policies are common to all business lines, while
operational procedures are tailored as necessary to the needs and
Consisting of 46 concrete towers, the Gouda Wind
Farm, situated in the Cape Winelands District, is
one of the largest wind farms in Southern Africa,
and the first to use locally produced concrete
instead of the usual imported steel towers.
characteristics of each business line.
As a final accolade for Sika SA, this project won the
coveted Fulton Award for Innovation in Concrete. Since the
emphasis on this huge project was to use local content and
local labour, it surpassed all expectations, proving local really
is best.
Sika SA is proud to have been chosen as one of the major
suppliers for this prestigious and groundbreaking project. It
looks forward to continuing to supply Sika’s innovative and
sustainability-enhancing products to many more one of the
foremost sustainability projects in South Africa.
Special Mention