Classification of cements in ASTM C 150 is made on the basis of bulk chemistry, fineness, and, for some cements, limits on phase abundance [1]. Monitoring quality of clinker and cements is a critical portion of the production process and the needs for rapid assessment lead to the application of X-ray fluorescence analysis. Estimates of phase abundance are derived from the bulk chemistry using formulas referred to as the Bogue calculation. Errors in these estimates derive, in part, from the variability of clinker phase chemistry relative to the assumed compositions, and by not accounting for minor constituents [2, 3].
Ultimately, the crystalline phases and not the bulk chemistry influence cement performance properties. Phase composition and clinker texture are controlled by the source material composition and processing, the kiln operating conditions, and subsequent grinding with calcium sulfates to make the hydraulic cement. Direct measurement of phases by X-ray powder diffraction (XRD) has been sought as an alternative approach for quantitative phase analysis in a number of studies [4, 5, 6, 7]. Application of improved measurement techniques of cement phase composition and texture will provide a means to improve our knowledge of their influences on a cement's hydration characteristics, and the development of strength and durability of a structure, making concrete a more predictable construction material.