Cement is used as a raw material in the construction of buildings, tunnels, dams, and bridges. Basically, cement consists of clinker, calcium sulfate hydrate as a plaster component, aggregate, and water. The four major components of cement have different characteristics of time for hardening and strengthening of the cement; for example, alite strengthens in a short period whereas belite strengthens over a long period. Therefore, the composition of the four major components in the clinker is changed for various construction types since cement is used for a wide variety of purposes.
Ordinary Portland cement is a popular cement. The hardening speed of high early strength Portland cement with high alite concentration is much faster than for ordinary Portland cement. High early strength Portland cement is used as emergency construction concrete and winter concrete. A moderate heat Portland cement, which is used for making dams, with low heat of hydration, has a large concentration of belite. Therefore, composition analysis of clinker and cement is needed because many kinds of cements are required for various construction situations.
Composition of cement is evaluated by elemental analysis using X-ray fluorescence spectrometry (XRF) based on ASTM C114. On the other hand, X-ray diffraction (XRD), a rapid analysis method for crystalline phases, can be applied to identify components of clinker and cement in addition to quantitative analysis by Rietveld refinement because the four major components are contained in clinker as crystalline phases. In this paper, XRD was applied to cement analysis and some applications are introduced.