RM 8486 exhibits an intermediate crystal size and high heterogeneity relative to the other clinkers that may result in greater spread in the phase fraction estimates (Figure 7). Alite (Figure 8) shows reasonable comparability among XRD, OM-1 and RR-1, with RR-2 and RR-3 being higher. OM-1 with its 4 points has significantly greater spread (IQ-range) than the more tightly grouped XRD numbers. For belite (Figure 9), the optical points diverge from the XRD yet demonstrate reasonable agreement along themselves, although OM-1 again displays large variance, with only the lowest point comparing favorably with XRD.
Aluminate values (Figure 10) do not demonstrate good agreement among XRD and optical data. Here OM-1 appears to be a lowlier. This may result from the fine crystal size and resulting difficulty in seeing this phase. Ferrite estimates (Figure 11) exhibit reasonable agreement among XRD, OM-1, and RR-1, both in terms of level (mean/median) and spread. Periclase estimates (Figure 12) fall into two groupings with respect to the mean/median: XRD/OM/RR-2 versus RR-1/RR-3.
Figure 8: Backscattered electron SEM images of RM 8486 at low (a) and high (b) magnifications show the heterogeneous texture and intermediate crystal size with alite (A), belite (B), ferrite (F), aluminate (AL), periclase (M), and pores (P).
Figure 9: Box plot for RM 8486 alite phase estimates by QXRD, optical microscopy (OM), and round robin (RR).
Figure 10: Box plot for RM 8486 Belite.
Figure 11: Box plot for RM 8486 aluminate
Figure 12: Box plot for RM 8486 ferrite.
Figure 13: Box plot for RM 8486 periclase.