Architect and Builder August/September 2019 | Page 55

resistance to seismic events are well document,
hence it needed no additional motivation as the
building material of choice. In addition to the above,
developments in concrete mix designs over the
last few years have increased the environmental
consideration of concrete use, specifically relating
to incorporating slag in the concrete mix.
The concrete contained a high slag content,
which is a by-product of steel production, is
used to ensure the durability of the concrete
and limit early thermal shrinkage/cracking of the
concrete. Special care was taken with both the
mix design and the construction procedure. Pour
breaks and construction joints were carefully
considered to mitigate the impact of shrinkage
and the erection and installation sequence of the
construction. Casting of floor slabs was mostly
scheduled to occur in cooler temperatures during
late afternoons and early evenings to assist in
reducing the effect of heat and cold on materials
(thermal effects). Given that the construction took
place as the City of Cape Town was experiencing a
drought, snagging was offset using a combination
of curing compounds, wet sand and hemp sheets
for vertical members.
The building is a calculated play on concept,
massing and forms whilst addressing intense
requirements from a space planning and work
environment point of view. The result is a building
which has successfully created an inspirational
environment where the organisation has flourished
and settled for years to come.
1ST FLOOR
3RD FLOOR
Water & Sanitation
6TH FLOOR
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