Quantitative analysis of C3S M1/M3 in CEM Ι using ARL X’TRA Companion benchtop XRD

Significance of XRD Analysis in Cement Quality Control

Understanding the crystalline phases in cement is critical for optimizing performance and durability of concrete and related materials. X-ray diffraction (XRD) enables non-destructive identification and quantification of polymorphic forms of tricalcium silicate (C3S) and other cement phases, guiding production adjustments, ensuring regulatory compliance, and improving end-product properties.

Objectives and Study Overview

This application note demonstrates the use of a bench-top XRD system for quantifying C3S M1 and M3 polymorphs in ordinary Portland cement (CEM I). Key aims include:

• Evaluating rapid data collection capability for process control.
• Assessing reproducibility of phase quantification over multiple measurements.
• Validating results against ASTM C150 specifications.

Instrumentation

The measurements were performed on a Thermo Scientific ARL X’TRA Companion bench-top XRD system featuring:

• θ/θ goniometer in Bragg-Brentano geometry (160 mm radius).
• 600 W X-ray source with selectable Cu or Co target and Ni filter.
• Solid-state pixel detector enabling high count rates and fast scans.
• Divergence and Soller slits for beam collimation, plus a beam knife to reduce air scattering.
• Optional water chiller for temperature control.

Methodology

Experimental conditions comprised:

• Reflection mode measurement of CEM I powder using Cu Kα radiation and Ni filter.
• Eleven consecutive scans, each lasting five minutes, to evaluate reproducibility.
• Phase quantification via Rietveld refinement in Profex using the fundamental parameters approach (BGMN algorithm).
• Reference crystal structures selected from literature (Aranda et al., 2012).

Results and Discussion

Rietveld refinements yielded weight percentages for major and minor phases with one-sigma standard deviations indicating high precision:

• C3S M1: 22.6 % ± 1.2 %
• C3S M3: 50.9 % ± 1.2 %
• Total C3S: 73.5 % ± 0.4 %
• C4AF: 10.0 % ± 0.2 %
• C2S β: 2.2 % ± 0.3 %
• C3A (total): 6.4 % ± 0.2 %
• Calcium sulfates (total): 6.3 % ± 0.3 %
• Minor phases (calcite, lime, periclase, quartz): < 1 % each.

The measured composition complies with ASTM C150 limits for OPC Type I. Zoomed diffraction profiles confirm accurate separation of M1 and M3 peak contributions.

Practical Benefits of the Method

The combination of rapid data collection and one-click Rietveld refinement offers:

• High throughput for routine process control in cement manufacturing.
• Robust reproducibility, with relative standard deviations around 1 % for key phases.
• Comprehensive phase analysis including minor constituents without extensive sample preparation.
• Automated result export to laboratory information management systems (LIMS).

Future Trends and Applications

Advances in detector technology and software are expected to further reduce acquisition times, enabling near real-time feedback on clinker formation. Potential developments include:

• Integration of in-situ XRD for monitoring phase transitions during heating.
• Machine-learning algorithms for automated phase identification and anomaly detection.
• Expanded use of portable XRD in field laboratories for on-site quality assurance.

Conclusion

The ARL X’TRA Companion bench-top XRD system delivers fast, reliable quantification of C3S polymorphs and other cement phases in less than five minutes. Its ease of use and automated Rietveld analysis make it an ideal solution for industrial cement quality control, satisfying ASTM C150 requirements with high reproducibility.

Reference

• N. Döbelin and R. Kleeberg, Journal of Applied Crystallography, 2015, 48, 1573–1580.
• M.A.G. Aranda, A.G. De la Torre, and L. León-Reina, Reviews in Mineralogy & Geochemistry, 2012, 74, 169–209.