The Civil Engineering Contractor November 2018 | Page 7

POLICYMAKERS
Bryan Perrie, managing director of The Concrete Institute.
and execution of work, respectively. Various methods
were used for testing of fresh and hardened concrete.
Also, there were separate standards for each of: cement,
GGBS, fly ash, silica fume, water, and aggregates. South
Africa adopted the European standard for cement over 20
years ago.
“Generally, South Africa has always followed UK codes
and adapted them slightly. The risk when you adopt codes
lock, stock, and barrel, is that some of them work and some
don’t — they may not be appropriate, or conservative
enough for local conditions. The problem we’ve had in
South Africa is that the British codes have been withdrawn
as they’ve now had to adopt or adapt the EU codes.”
• Loading code: South Africa has adapted the EU code
for the basis of structural design (EN-1990) as SANS
10160. Where necessary, local requirements and
conditions were allowed for.
• Design of Water Retaining Structures: In terms of the
water-retaining code, we are also in the process of
adopting the EU code, but unfortunately that code
cannot be approved until the structural design code is
first approved, as they are interlinked There are some
issues relating to the structural design code; primarily,
differences in materials and practices, and the fact that
adopting an EU code immediately refers to hundreds if
not thousands of other EU codes that we have not yet
necessarily adopted.
A working committee made a decision in 2007 to adopt
the EU standard EN-1992-1-1 with our own set of
nationally determined parameters. Perrie explains that
the process is to adopt responsibly through comparative
calculations; reviewing local implications; identifying and
motivating the choice of nationally determined parameters;
and characterising South African material properties. “In
www.civilsonline.co.za
terms of the timeline, the working group was formed in
August 2007 and undertook a review of relevant parts
during 2007 to 2010, and a draft document to the National
Annex was prepared in 2012. Since then, we have been
involved in a debate with the SABS: For the annexure to
make sense, it has to have the same numbering as the EU
code, but the SABS does not allow that as it has its own
numbering system.”
Regarding construction specifications, Perrie points out
that these have historically been prescriptive in nature
with “some performance requirements”. Recently,
with the introduction of durability issues, a change has
become required.
Changes recently have aimed to add properties to
control ‘covercrete’ and specify those actual properties that
prevent deterioration. There is a move towards preventing
ingress of chlorides, ingress of CO 2 , and poor curing.
“In terms of durability, the Europeans have had a very
different philosophy to us, which has now become our
philosophy. The first approach is to look at what physical
environment your building will be constructed in and
thereafter to decide how long it needs to stand in that
environment and how to make it durable enough to
withstand that environment for the required length of time.
You then design it to stand up. This involves a big change in
the way we look at designing structures,” he says.
The way forward
“In South Africa, the working group decided to adopt EU
specifications EN-206 Concrete, EN-13670 Execution of
Concrete Structures; and, just as the UK is developing
two guidance documents with the same numbering as the
EU documents and incorporating a lot of current 10100-2
information, so have we. In this we have sought to include a
lot of very good guidance currently in our own documents.
However, we’ve run into another brick wall with SANS
over the numbering, because in our view, you have to have
the same numbering so you can cross-refer.”
Currently, there are two committees working on the
two guidance documents and once that is complete, the
results will be circulated to large industry groupings
and the final submission made to SANS for its public
approval process.
“In respect of admixtures, some years ago, we adopted
the EU standards and we have a document for this: SANS
50934. We have decided not to adopt the EU aggregate
specifications, as the EU has quite a different family of
materials to ours. We have kept SANS 1083, and there is
now a new working group on this. The intention is that the
new aggregate specifications will include natural aggregates;
non-natural aggregates such as slags and possibly ashes; and
also recycled aggregates. It will be renamed Aggregates for
Construction. All the specifications for aggregates will be
in one document with six parts, which will make life easier
for quarries. A working committee is meeting shortly to
rationalise the number of different gradings of aggregates,”
says Perrie. nn
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