Quantitative Rietveld analysis of the amorphous content in cements and clinkers

The potential presence of an amorphous content in OPC clinker and cements is usually overlooked when studying their phase composition. This is largely because of the difficulty in determining amorphous content experimentally. Despite this difficulty, the study of amorphous content and composition in these materials has merit due to the likely effects on the reactivity of the resulting cement. This paper applied the Rietveld method using X-ray powder diffraction data to determine the amorphous content of a number of materials, including clinker, cements and single phases. The cementitious materials were found to contain widely varying, but significant, amorphous contents. The addition of amorphous slag to change the amorphous content by a known amount, gave results as expected from the calculated results for the pure cement and clinker amorphous contents. The results are discussed in relation to other studies published on the issue of amorphous content in cementitious materials.Les \ue9tudes sur la composition chimique du clinker et des ciments Portland font g\ue9n\ue9ralement peu cas de la pr\ue9sence potentielle d'une concentration amorphe, en raison, notamment, de la difficult\ue9 de d\ue9terminer cette concentration de mani\ue8re exp\ue9rimentale. En d\ue9pit de cette difficult\ue9, l'\ue9tude de la concentration amorphe dans ces mat\ue9riaux et de leur composition chimique a son m\ue9rite, ne serait-ce que pour les effets probables sur la r\ue9activit\ue9 du ciment r\ue9sultant. Les chercheurs ont appliqu\ue9 la m\ue9thode Rietveld combin\ue9e \ue0 des donn\ue9es sur la diffraction de rayons X sur poudres pour \ue9tudier la concentration amorphe d'un certain nombre de mat\ue9riaux, dont le clinker, les ciments et les phases simples. Leur \ue9tude a montr\ue9 que les liants hydrauliques contenaient pour la plupart, mais \ue0 des degr\ue9s diff\ue9rents, des concentrations amorphes. L'ajout de laitier amorphe pour modifier la concentration amorphe par une quantit\ue9 d\ue9termin\ue9e a donn\ue9 les r\ue9sultats escompt\ue9s, \ue0 partir des r\ue9sultats calcul\ue9s, pour les concentrations amorphes dans le ciment pur et le clinker. Le rapport discute les r\ue9sultats \ue0 la lumi\ue8re d'\ue9tudes comparables sur la concentration amorphe dans les liants hydrauliques.Peer reviewed: YesNRC publication: Ye