THE REAL THREAT OF USING SUB-STANDARD CEMENT

Njombo Lekula, MD of PPC
RSA, warns that sub-standard cement products are
threatening the built environment industry and placing South African lives at
risk. Use of sub-standard cement can
negatively affect the sustainability of buildings and structures thereby
leading to increased repair or maintenance costs, injuries and fatalities due
to structural failures or collapse.

During a routine market
surveillance exercise whereby competitors’ products were tested for comparison,
PPC found that some products were sub-standard and warranted further
investigation.

In an effort to protect the
greater South African cement industry and consumers, PPC appointed Beton-Lab, a
South African National Accreditation System (SANAS) accredited independent
laboratory in September 2017 to physically purchase bags of cement in order to
maintain the chain of custody and assure no interference from any outside
party.

Photographs of each bag
(front, side, back panels and bag weights) were taken to verify Letter of
Authority (LOA) numbers, cement type and strength class. The weights of the
bags were checked and EN strength testing in accordance with SANS 50197 for 2, 7
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 results showed an 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 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 some 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 sustainability and impact on our
infrastructure. With non-compliance of quality and durability standards,
consumers are unaware of the risk they face.

It takes up to 28 days for
cement to develop strength and fly ash does not start developing strength
before 28 days. The durability of mortar or concrete is primarily dictated by
the amount and the strength performance of the cement that is used.

Retailers, builders and
construction companies are also at risk of future legal action or loss of
income as selling and using these sub-standard products can have a negative
effect on the perception consumers have of their businesses and standards.

Lukela concludes, “The use
of sub-standard cement products has been identified as one of the main causes
of building collapse globally. PPC has decided to take a stand against sub-standard cement products to ensure the
safety of consumers and longevity of structures.”

More information from www.ppc.co.za