The number of industrial and academic users of the quantitative phase analysis of cement according to Rietveld has been rapidly increased in the last few years. However, interlaboratory tests have shown that in part considerably diverging contents, especially for C3S/C2S and C3A, have been found in the individual working groups. On the one hand, this is due to different preparation techniques. On the other hand, software programs for the analytical method according to Rietveld permit different approaches as regards the refinement strategy. Thus, the results can only be compared up to a point.
Now, the section ‘construction chemistry’ within the Society of German Chemists (Gesellschaft Deutscher Chemiker – GDCh) has started to tackle this problem by establishing a working group “Rietveld”. As the chairman of the section, Prof. J. Plank, underlined during the first meeting of the working group at Munich Technical University, the goal is to develop a protocol for the methodical approach with the Rietveld analysis, which allows to come close to the actual phase content as accurately as possible. Furthermore, awareness for the efficiency of this method is to be created.
The 15 participants of the first meeting decided to form sub-groups dealing with the following topics: (1) sample preparation, (2) instrument parameters, (3) phase identification and (4) refinement strategies. The results of the sub-groups will be presented by the coordinators during the next meeting at Munich Technical University on 13.04.2010. As soon as a method protocol will be available, the phase contents that can be achieved by using it should be compared with other analytical methods. It is planned to publish the final protocol in a scientific journal. The working group “Rietveld” is open to members of the section ‘construction chemistry’, but also to guests. For more information contact the GDCh office (email@example.com) or the coordinator of the working group (firstname.lastname@example.org).