Volume 7, Issue 7 (July 2010)
Statistical Calibration of ASTM C150 Bogue-Derived Phase Limits to Directly Determined Phases by Quantitative X-Ray Powder Diffraction
Statistical analyses of companion Bogue (ASTM C150-07) and quantitative X-ray powder diffraction (QXRD) estimates for cement phases are used to establish the most likely linear relationship between these two measurement techniques for alite, belite, aluminate, ferrite, and for the combinations (C3S+4.75⋅C3A) and (C4AF+2⋅C3A) used to characterize heat of hydration and sulfate resistance, respectively. This cross-calibration was performed using published data from more than 194 Portland cements, spanning more than 50 years of manufacture. Each resulting calibration is a linear relationship, reported with 99 % Working–Hotelling–Scheffé confidence limits from the least-squares regression. Fieller calibration intervals are used to report bounds for the QXRD values corresponding to the Bogue limits given in ASTM C150-07, Table 1. Such bounds could allow either technique to be used for phase estimation to assess the compliance of a Portland cement.