First Africa-wide comparative study for cement testing

Limestone, clay, sand, and gypsum are the main components of cement. "When you order cement in Germany, you know what you will get and how well it will perform" says building materials expert Wolfram Schmidt. However, in many African countries you cannot always know that with the same degree of confidence. "Therefore, quality assurance testing is very important for building safety", the BAM Federal Institute for Materials Research and Testing engineer continues.

To improve long-term quality, BAM, together with the German national metrology institute (Physikalisch Technische Bundesanstalt (PTB)) organised the first Africa-wide comparative study on cement testing in early July in the Tanzanian city Dar es Salaam. 27 laboratories from 18 African and two European countries participated in the proficiency test scheme, a so called round robin test. In addition to comparative analysis, a further objective of the initiative was to promote better networking among African experts.

In Europe, round robin tests are commonplace, and an obligation for building materials laboratories - they are mandatory for being allowed to conduct tests at all. In these tests, identical samples are examined with identical or different processes. Round robin tests create trust, says initiator Wolfram Schmidt. This is particularly significant in Africa, because in most regions, markets are booming and international investors are very interested in having reliable partners for the quality control of their products. So far, there has been almost no exchange between the individual laboratories in Africa. In many African countries there are simply not enough cement and concrete experts around, and in many places the technology lags behind the global standard by decades.

Cement is a high-tech product, a mixture of finely ground inorganic and non-metallic components. It serves as a binder for concrete. The base material, the so-called clinker which is kiln-fired lumps, is a global commodity. Unlike in Europe where there is a dense network of cement producing plants, in most African countries cement and clinker are imported from many different sources depending on where it is cheapest. Frequently cements are then blended with supplementary materials that are available locally.

In addition to the two-day event on July 5 and 6 in Dar es Salaam, there will be a final workshop at BAM in Berlin in beginning of 2013. The round robin test originated from the BAM coordinated SPIN research project whose participants will meet in Tanzania at the same time, holding courses in cement and concrete technology for students from the project's partner countries. SPIN is a network in which seven African and three European countries have been working together to develop cement and concrete technology adapted for Africa, since 2011.

Contact:
Dipl.-Ing. Wolfram Schmidt
Department 7, Safety of Structures
Email: wolfram.schmidt@bam.de

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