Substandard cement products are threatening the built environment industry and placing South African lives at risk, says PPC South Africa MD Njombo Lekula.
He explains that the use of substandard cement has various implications that may negatively affect the sustainability of buildings and structures, thereby leading to increased repair or maintenance costs, injuries and fatalities as a result of structural failures.
What started out as a normal market surveillance exercise, whereby all competitors’ products were tested for comparison, PPC soon found that some products were substandard and the company felt this warranted further investigation.
To ensure the results remained independent, Lekula tells Engineering News Online that the company contracted Beton-Lab, in Kempton Park, to carry out a number of tests on various cement products over two years.
According to Lekula, the results show a deterioration in cement products as “the times become tougher and tougher”, which he says shows that some producers are starting to “take shortcuts” in producing their products.
Because of this, PPC engaged with authorities – such as the South African Bureau of Standards (SABS) and the National Regulator for Compulsory Specifications – on the company’s findings.
However, Lekula laments that it soon became clear that authorities did not have sufficient resources to better monitor these products.
Beton-Lab, a South African National Accreditation System- (Sanas-) accredited independent laboratory, bought the bags of cement for testing 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 to verify its Letter of Authority (LOA) numbers, cement type and strength class. The weights of the bags were then checked and the strength testing, in accordance with SANS 50197, for two, seven and 28 days was performed.
The SABS prescribed uncertainty of measurement allowance of 2.5% was applied when analysing the resultant data, the results of which show the inability to produce a consistent quality product and thwarting of standards.
Commenting on the lab’s findings, Beton-Lab MD Alan de Kock says the lab’s work is “tightly controlled, [thereby] ensuring accurate data that is in no way influenced by outside parties”.
According to Lekula, nonconformity of strength and weight 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 substandard cement products carry the SABS mark, even though the SABS stamp is considered to be a mark of regulatory approval which instills trust in the product being sold and, if used in accordance with the instructions, will result in a structure that is robust and safe.
Even though local cement producers have stringent internal quality regulations in place to ensure compliance of their products, with cement producers supplying the market with substandard extended products, Lekula questions the long-term effect on the South African built environment, as well as the sustainability and impact on the country’s infrastructure.
With noncompliance of quality and durability standards, consumers are unaware of the risk they face.
The way forward, in this respect, he tells Engineering News Online, will be to ensure that consumers are educated in the sense that affordable does not always mean poor quality, nor that cheaper is better.
However, for consumers to identify a substandard product, other than doing the actual testing of the product, Lekula suggests that consumers consider the pricing of the product.
He suggested that the simplest way for consumers to ensure they are buying quality products, is to “stick to the products that [the consumer] knows”.
Retailers, builders and construction companies are also at risk of future legal action or loss of income as selling and using these substandard products can have a negative effect on the consumer’s perception of their businesses and standards.
“The use of substandard cement products has been identified as one of the main causes of building collapse globally,” Lekula laments, adding that “PPC has decided to take a stand against substandard cement products to ensure the safety of consumers and longevity of structures.”
On a side note, 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.