TECHNOLOGY
An on-site laboratory is more efficient, but the
basic tests can nonetheless be done manually.
VALUE OF TESTING
LIES IN THE SAMPLING
By Eamonn Ryan
Many tests are conducted
to check the quality of
aggregates, the core
components of concrete
and road building, therefore
aggregate quality really
matters.
22_QUARRY SA| JANUARY/FEBRUARY 2019
T
he nature of mining is that there
is no guarantee as to the quality of
material throughout production.
It’s a changing landscape (no pun
intended).
Stones don’t always break in an exact
square according to a formula. SANS
1083 permits a certain range of results,
provided it falls within the specification
envelope. This often leads to unhappiness
between the customer and the supplier.
Where aggregate is marginally out-of-
spec but still usable, it is simply sent back
at enormous cost to the mine. Worse,
if it has already been used to make a
concrete floor which develops problems –
subsequent problems may be attributed to
the quality of the aggregate.
This leads to a costly dispute between
quarry and customer – and only if the
quarry has evidence of a consistent testing
history will the odds be in their favour.
Afrimat Glen Douglas, a dolomite
quarry in Henley-on-Klip which
commenced operations in the 1950s, has
a dedicated on-site laboratory to regularly
test its aggregate. Implementing a
Quality Management System minimises
such disputes.
“The moment a customer sees a quarry