SA Affordable Housing March - April 2020 // ISSUE: 81 | Page 18

FEATURE
The floor system comprises rectangular-shaped reinforced or
pre-stressed precast-concrete ribs supporting rebated filler blocks.
purchase the bags themselves in order to maintain the chain
of custody and assure no interference from any outside party.
Part of the process was to take photographs of each bag
(front, side, back panels and bag weights) to verify Letter of
Authority (LOA) numbers, cement type and strength class. The
weights of the bags were checked and the EN strength testing
in accordance with SANS 50197 for two, seven and 28 days
was performed. The South African Bureau of Standards
(SABS) prescribed ‘uncertainty of measurement allowance’ of
2.5% was applied when analysing the resultant data. The
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MARCH - APRIL 2020
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results show the inability to produce a consistent quality
product and thwarting of standards. Alan De Kock, MD of
Beton-Lab says, “As an independent laboratory our work is
tightly controlled, ensuring accurate data that is in no way
influenced by outside parties.”
The report was recently released, and the findings were
shared with the SABS and the National Regulator for
Compulsory Specifications (NRCS), showing continued
non-performance of the cements tested. According to Lekula,
non-conformity of strength and weights of some products
ranged from 11% to 73% of the sample set. “This failure to
conform to local standards not only has an impact on the
structural integrity of buildings, but also poses a threat to
possible damage of property and even loss of life should the
walls come tumbling down.”
It was also found that most of the sub-standard cement
products carry the SABS mark. The SABS stamp is a mark of
regulatory approval, instilling trust in the product being
sold and, if used in accordance with the instructions, will
result in a structure that is robust and safe. Local cement
producers have stringent internal quality regulations in
place to ensure compliance of their products. However, with
cement producers supplying the market with sub-standard
extended products, Lekula questions the long-term effect
on the South African built environment as well as the
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