Modern Quarrying Q1 2020

CEMENT

Following PPC’s findings, the results have been presented to both the SABS and the NRCS, and action has already been taken in some instances.

weights of some products ranged from 11% to 73% of the sample set. The third aspect of concern was the standard deviation. “This refers to inconsistency in the product, where fluctuation of quality is a major concern,” explains Lekula. “The 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. Challenges in policing Lekula believes one of the chal- lenges for the relevant authorities in policing the industry is that the two organisations responsible – the SABS and the NRCS – are seri- ously underfunded, which affects their capacity. “Both the SABS and NRCS should be conducting regular surveillance visits on sites to check if producers are compliant at all times. Unfortunately, the two organ- isations are basically funded by the levies they collect from the SABS

PPC believes that its actions are in the best interests of the South African consumer and the cement industry at large.

makes a standard cube of concrete and keeps it in a controlled condition for the prescribed two, seven and 28-day intervals. In any of those intervals, a cube is crushed to measure strength. If a product is a 32.5, for example, it means that in 28 days it should crush at 32.5 MPa. “To give an idea of the extent of the quality shortcomings, one of the products tested crushed at 3 MPa after a 28-day period,” says Lekula, adding that non-conformity of strength and

product and thwarting of standards in most cases. “Some of the products failed horrendously,” says Lekula “Firstly, the products failed on bag weight. In some instances, some of the bags were found to weigh around 46 kg, which is 4 kg short of the required 50 kg. That is unfair to the consumer. Secondly, we picked up products that did not meet the standard in terms of strength development.” Explaining the strength testing process, Lekula says the laboratory

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MODERN QUARRYING QUARTER 1 - 2020