Raman Imaging of Cementitious Systems

The chemical composition and mineralogy of heterogeneous materials are key to understanding their behavior and performance. Specifically, for construction materials such as aggregates and cements, elucidating the phase mineralogy at a fundamental scale is crucial for predicting their performance. Most investigations obtaining chemistry and mineralogy, have relied on methods such as NMR, X-Ray Diffraction, and electron and optical microscopy. These methods when combined provide much more information on the complex heterogenous materials, despite having certain limitations. Raman imaging is a complementary high-resolution imaging technique that allows direct fingerprinting of minerals, including their polymorphs. Here, using a newly developed analytical methodology, an accurate and rapid mapping protocol to quantify a variety of static heterogeneous systems such as cements, fly ashes, waste-to-energy ashes, and granites is reported. In addition, an application of this diverse technique to map cement paste carbonation, a dynamic phenomenon, is demonstrated. These results pave the way for future application of Raman imaging such as the design of sustainable materials and monitoring of concrete’s performance.