Advancing Characterization of Cementitious Systems via Raman Imaging

The drive for sustainability within the cement industry has resulted in the formulation of complex low-carbon cements that show considerable variation in their mineralogical phases, chemical compositions, and particle sizes. These differences can impact the workability, strength, and durability of concrete. Accurately characterizing these properties is challenging and requires a combination of techniques such as microscopy, spectroscopy, and diffraction. Raman imaging is particularly valuable for investigating the entire lifecycle of cement, covering everything from anhydrous cements to hydration and long-term durability. Here, we present its capability to analyze the phase composition of Ordinary Portland Cement (OPC) and Calcium Sulfoaluminate (CSA) cement. We also showcase how Raman imaging can assess the carbonation front in the cementitious system and map the products of alkali-silica reactions (ASR) in mortar samples. This contributes critical insights into the mechanisms of concrete degradation. This positions Raman imaging as a complementary method to electron imaging, facilitating a thorough concrete characterization.