Raman Spectroscopy Applications in Cement Chemistry

Raman spectroscopy has become an indispensable tool for characterising the complex phases and reaction pathways in cementitious materials. By probing vibrational fingerprints of crystalline and amorphous species, it reveals polymorphs, hydration products and degradation phases with minimal sample preparation. In cement chemistry, Raman techniques enable non-destructive mapping of clinker minerals, quantification of carbonation depth, monitoring of sulfate or chloride attack, and assessment of supplementary cementitious materials. Advances in confocal imaging and fibre-optic probes permit in situ, high-resolution phase mapping of hydration gels, portlandite and ettringite, while emerging applications of near-infrared photoluminescence offer non-contact detection of microcracks and formulation identification. Combined with complementary methods such as thermogravimetry, scanning electron microscopy and density functional theory, Raman spectroscopy now delivers both spatially resolved chemical maps and quantitative phase information critical for optimising durability and sustainability in cement and concrete technology.

Research from Nature Portfolio

Recent studies have introduced high-fidelity Raman imaging protocols capable of auto-focusing and Z-mapping on rough, unpolished samples. This methodology exploits characteristic peak intensity ratios to distinguish polymorphs at sub-micrometre resolution, demonstrating accuracy exceeding 97 % for phase identification in heterogeneous systems. Such innovations pave the way for rapid, direct fingerprinting of minute clinker and hydration phases in cement–based materials without laborious preparation.

Another development has harnessed near-infrared photoluminescence of Portland cement to create a non-contact diagnostic tool. The detected emission around 1,140 nm is attributed to silicon species within calcium silicate phases and remains stable across hydration states. Application of a thin opaque coating enables detection of microcracks by revealing the underlying luminescence, offering a novel route to non-destructive monitoring of crack initiation and progression in cementitious structures.

Raman Spectroscopy Applications in Cement Chemistry publication trend

The graph below shows the total number of articles in raman spectroscopy applications in cement chemistry across all publications each year (not limited to Nature Index journals).

Technical terms

Raman spectroscopy: A vibrational spectroscopic technique that identifies molecular and crystalline phases via inelastic scattering of monochromatic light.

Confocal Raman microscopy: A Raman approach employing spatial filtering to achieve high-resolution, three-dimensional chemical mapping.

Carbonation: The chemical reaction of CO₂ with hydration products, notably portlandite and calcium silicate hydrate, forming calcium carbonate.

Portlandite: Crystalline calcium hydroxide, Ca(OH)₂, commonly formed during cement hydration.

Ettringite: A needle-shaped hydrated calcium aluminium sulphate phase, formed early in cement hydration and involved in sulphate attack.

Calcium silicate hydrate (C-S-H): The principal binding phase in hydrated cement, responsible for mechanical strength and durability.

Near-infrared photoluminescence: Emission of light in the 700–1,400 nm range when a material is excited, used here to detect silicon-related luminescence in cement.

References

1. High-fidelity and high-resolution phase mapping of granites via confocal Raman imaging. Scientific Reports (2021).
2. Near-infrared photoluminescence of Portland cement. Scientific Reports (2022).
3. Quantitative evaluation of cement paste carbonation using Raman spectroscopy. npj Materials Degradation (2021).
4. Real‐time monitoring of carbonation of hardened cement pastes using Raman microscopy. Journal of Microscopy (2022).
5. Optimising confocal Raman microscopy for spectral mapping of cement-based materials. Materials and Structures (2022).
6. Monitoring the cementitious materials subjected to sulfate attack with optical fiber excitation Raman spectroscopy. Optical Engineering (2013).
7. Combining Raman Spectroscopy, DFT Calculations, and Atomic Force Microscopy in the Study of Clinker Materials. Materials (2021).