Has the adoption of the European cement specification (EN 197) improved cement consistency in South Africa?In 1996, South Africa adopted the European Cement Specification (EN 197) and discontinued the specifications under which cement previously had been manufactured. These were based on British specifications (BS 12) which had a minimum requirement for strength at 3 and 7 days, using a water/cement ratio of 0.4. The European specification has early age strength hurdles with statistically-determined upper and lower control limits for standard (28-day) strength determinations. A water/cement ratio of 0.5 is used in the strength determination. An analysis was conducted on cements produced at specific factories, measuring the strength performance for the ten years prior to the change against the ten years after the adoption of the new standard. Assumptions were made on the strength classes in order to do the comparison. The results are inconclusive in that the performance and consistency of cements from some factories have improved, while in other cases it has deteriorated.
|Author: A.W. Walker, M.J. Kearns|
|Section: Standartization and quality|
|Keywords: cement quality, manufacturer of South Africa, optimization, cement composition|
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