It is difficult to quantify the amorphous and crystalline phases of cement materials due to the complexity of the mineral phases in the mixture and the significant overlapping peaks. Excellent results can be obtained by Rietveld refinement of the measured sample using standard measurement configurations. This can be further improved by using primary multilayer Kα1.2 monochromators instead of conventional Kβ filters.

Qualitative phase analysis

Portland cement, with clinker accounting for about 95% of its composition, is in the form of calcium oxide, silicon dioxide, alumina and iron oxide in the form of alite and Belite (CaO/SiO2 compounds), aluminate (CaO/Al2O3) and ferrite (CaO/Al2O3/Fe2O3). Qualitative analysis of the measurement data makes it easy to identify these four main compounds found in Portland clinker.

Quantitative analysis

After identifying the four main phases present in Portland cement clinker, Rietveld finishing was performed to calculate the corresponding phase proportions. Table 1 compares the mass scores obtained from Rietveld refinements of XRD data with the values in NIST SRM 2688 CoA.