53 / 56
51
CONSTRUCTION WORLD
MAY
2017
“Concrete is changing the face of South
Africa’s landscape. One only has to consider
the high number of truly impressive
structures competing for the 2017 Concrete
Society of Southern Africa’s Fulton Awards
to see how many cutting-edge architects
and engineers are making concrete their
material of choice,” Perrie states.
He says concrete’s versatility is the
material’s first major positive factor. “As
requests for changes are common in any
construction project, the design flexibility
of concrete allows the contractor to
accommodate design changes after the
process has begun.
“As for aesthetic appeal, the range of
colours and textured finishes available in
concrete is amazing. Mixing and matching
colours and textures provide a spectrum of
design possibilities. Concrete textures can
resemble smooth, high-polished granite
or exposed aggregates with a rugged feel.
As natural stone becomes inaccessible or
the costs prohibitive, concrete is a natural
alternative for recreating traditional finishes
in a cost-effective way.”
Perrie says speed has become a top
priority in building. “When designing with
concrete, there is no delay as concrete is
readily available. Earlier start-up means
better cash flow for owners and developers.
It also could mean getting the jump on
rainy seasons.
“Should office tenant requirements
include sound transmission control,
the natural mass of concrete floor and
wall systems provides both acoustical
resistance and vibration control.
“Shallower floor systems are an
important structural advantage of concrete.
On average, the construction of concrete
buildings will allow one additional floor to
be created for each 10 stories of traditional
building height, resulting in more rentable
space for buildings of similar size. When
faced with height restrictions, concrete
construction is a key consideration and
could represent initial construction cost
savings and additional income generation.”
Perrie says advanced construction
techniques, such as ‘ flying formwork
systems’ , increase the speed of floor
construction. As a concrete frame
progresses upward, workers on the
completed floors below can proceed
with interior partitions, exterior finishing,
electrical, mechanical and plumbing
systems. “Concrete construction assists in
energy efficiency; a major consideration in
the life cycle cost analysis.
“With concrete cladding panels, a
great range of finishes and textures are
available. Precast panels are extremely
durable, weather resistant, offer superior air
tightness, increased sound attenuation and
thermal properties and are inherently fire
resistant. Concrete claddings permit fast
enclosure of the structure, allowing other
trades to start sooner, cutting construction
time, and reducing wall thickness to
maximize rentable space.”
Perrie adds that due to its longevity and
ease of construction, concrete is often the
most economical choice for engineered
structures. Load-bearing concrete exterior
walls serve not only to enclose the
buildings, but to carry roof and wind loads,
eliminating the need to erect separate
cladding and structural systems.
“When it comes to energy efficiency,
most concrete is produced locally, reducing
fuel requirements for handling and
transportation. Once in place, concrete
offers significant energy savings over
the lifetime of the structure. The mass of
a concrete structure makes it a thermal
reservoir with the ability to store large
amounts of energy. This thermal mass
Five major benefits of concrete
There are at least five major benefits in designing and building with concrete:
versatility, attractive appearance, cost-effectiveness, structural integrity, and
sustainability, says Bryan Perrie, MD of The Concrete Institute (TCI).
ABOVE:
Precast concrete panels offer wide
design possibilities as well as important
economic and practical advantages on
building sites.
BELOW:
The sky is the limit for designers
when creating structures with concrete.
Pictured: an innovative concrete roof in
Tenerife, Canary Islands.
allows concrete to help maintain a relatively
steady interior temperature.
“Finally, concrete is an inert material
that is easily recyclable. Old concrete that
has reached the end of its service life can
be reused as aggregate for new concrete
mixtures. The addition of industrial by-
products such as fly ash, silica fume and
blast furnace slag make concrete less
permeable while incorporating materials
that would otherwise be deposited in landfill
sites,” Perrie concludes.