Standard sand as the standard for worldwide monitoring of cement quality

摘要

Quality assurance and production monitoring have a long tradition in the cement industry that goes back to the time of the first product standard in the years 1877/78. Then, as now, the current product standard specified the minimum amount of testing needed to ensure that the cements conformed to the standards. Ever since the beginning of cement production the strength development has been an important cement characteristic for assessing the quality. At an early stage it was recognized that strength testing on mortar, i.e. on a mixture of cement, sand and water, is more meaningful than just testing the hardened cement paste. So far the subdivision of cements into strength classes in the standards has been taken into account in concrete technology. Modern concrete design, for example, is also based on the strength class of the cement to be used.