34
MODERN QUARRYING
October - November 2013
ASPASA/SARMA
VIEWPOINT
L
atest reports on the Tongaat Mall
collapse, point out that the eThek-
wini municipality has attempted to
stop construction since March this year.
A large section of the mall collapsed, kill-
ing two people and injuring 29 others.
The developer apparently ignored a sum-
mons issued six days before the tragedy,
to cease work on the site.
“This year in particular there have
been a number of reports of building
collapses claiming the lives of numerous
people and scarring surrounding commu-
nities,” Pienaar says. “In the wake of these
tragedies, investigations have almost
exclusively revealed that inappropriate
design and unsuitable building material
were to blame for the structure’s failure.
Incorrectly specified materials may lead to
failures immediately or in years to come
as a result of increased loads or more dan-
gerously, due to corrosion of foundations
from surrounding soil conditions.
“Technical expertise is vital and even
the size of the aggregates used in con-
crete, or the composition of sand, can play
a role in the future strength of a structure.
For example, acidic soil may corrode cer-
tain types of stone, eventually leading
to pitting and tunnelling of foundations
which can make it spongy and unsuitable
in years to come.”
He says the role of the engineer is
therefore critical in establishing soil con-
ditions and geological conditions for a
building. Also, in setting the specification
of suitable stones and sands to mix with
the cement (sometimes admixtures are
required), is therefore critical and these
should be adhered to by the construction
contractor.
“Unfortunately the entry of unli-
censed, unscrupulous quarry and mine
operators into the sand and aggregate
supply industry in South Africa is lead-
ing to some confusion. These operators
may claim to be mining a certain type of
aggregate at a certain location, when in
fact they do not have a mining licence
and are illegally obtaining it elsewhere.
At surface level the aggregates may look
the same – but they may have completely
different chemical compositions when
examined under the microscope,” Pienaar
maintains.
Certain precautions can be taken by
the industry to ensure correct concrete
mixes are obtained. Aggregates, for exam-
ple, must be obtained from an accredited
and registered Aspasa member. Where
Aspasa/Sarma director Nico Pienaar.
“Building collapses such as
those seen in Bangladesh and
Nigeria recently, may happen
in South Africa unless more
careful attention is paid to the
specification of appropriate
materials to meet each building’s
design criteria.” This warning was
issued by Aspasa/Sarma director
Nico Pienaar a few days before
the recent Tongaat Mall
building tragedy.
Building a nation on solid f
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