Getting it right
THE FIRST TIME
Strict adherence to quality control ensures that construction programmes are completed on time, on budget and within specification. IMIESA speaks to Amit Dawneerangen, GM: Sales & Product Technical at AfriSam, about the key role they play as a construction material supplier.
The road maintenance backlog is growing, and construction costs are escalating. How can AfriSam help fill the gap? AD AfriSam conducts extensive process control testing on all their products to ensure compliance with the relevant national standards. External testing is also conducted where required, especially on materials for road construction. Globally recognised methodologies include Polished Stone Value, Los Angeles Abrasion, and California Bearing Ratio tests. For road construction, our quarries manufacture G1 to G7 products for layerworks construction, and these products comply to the Colto specification. At most operations, our stone and crushed sand products are also suitable for use in asphalt production. Using the right materials in accordance with the design brief avoids the need for future unscheduled remedial works, which can result in substantial additional costs, depending on the nature of the project.
When it comes to aggregates, what are some of the pitfalls to note? First, cheap aggregate is not necessarily quality aggregate. Inconsistency of physical and inherent aggregate properties is another crucial factor to consider, since the wrong
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IMIESA April 2022
product will result in a subsequent pavement failure. AfriSam personnel conduct routine physical testing to ensure that material leaving the quarry is consistent, and inherent properties are checked every quarter. In addition, regular quarry optimisation meetings are held to ensure that all technical and production efforts are aligned. For example, benches are classified before each blast by testing the drill chips. This will establish if there are any hidden issues that may make the material unsuitable for specific products. It’s also essential to engage only with aggregate quarries that are legally registered to operate by the Department of Mineral Resources and Energy. In other words, quarries must have a valid mining licence and be environmentally compliant. In terms of the Mining Charter, they must also invest in the surrounding community. Another important point to note is that commercially accredited laboratories do not always yield consistent or accurate test results. That can lead to challenges on projects in terms of acceptance of material supplied. AfriSam’s internal laboratories provide an absolute quality assurance and material guarantee.
from our website, provides typical values for tests such as ACV, 10% FACT, PSV, fine aggregate angularity index and magnesium sulfate soundness, clay lumps and variables, fractured faces, SANS 1083 requirements and sand equivalent.
Should concrete surfaced roads be receiving greater acceptance in South Africa? The application or prevalence of concrete roads is largely dependent on it being specified by the client/engineer/designer. The following are some of the advantages of going the concrete route: - One of the greatest is their longevity – concrete roads can last between 20 to 40 years on average, which is two to four times the lifespan of asphalt. - Concrete can be recycled back into roads either by using it in the sub-base layers or by reintroducing it into the new concrete mix.
What solutions does AfriSam provide for the asphalt market? Where specialised materials are required for the production of proprietary products, AfriSam has the technical and production ability to partner with our customers to provide solutions. The AfriSam Technical Reference Guide (8.2 Edition), which can be downloaded
Amit Dawneerangen, GM: Sales & Product Technical, AfriSam
