Investigation of C3S hydration mechanism by transmission electron microscope (TEM) with integrated Super-X^TM EDS system.

Tricalciumsilicate (C3S, Alite) is the major component of the Portland cement clinker. Hydration of Alite is decisive in influencing the properties of the resulting material. This is due to its high content in cement. The mechanism of the hydration of C3S is very complicated and not yet fully understood. There are different models describing the hydration of C3S in various ways. In this work for a better understanding of hydration mechanism, the hydrated C3S was investigated by using the transmission electron microscope (TEM) and for the first time, the samples for the investigations were prepared by using of focused ion beam from sintered pellets of C3S. Also, an FEI Talos F200x with an integrated Super-X EDS system was used for the investigations. FEI Talos F200X combines outstanding high-resolution S/TEM and TEM imaging with energy dispersive X-ray spectroscopy signal detection, and 3D chemical characterization with compositional mapping. TEM is a very powerful tool for material science. A high energy beam of electrons passes through a very thin sample, and the interactions between the electrons and the atoms can be used to observe the structure of the material and other features in the structure. TEM can be used to study the growth of layers and their composition. TEM produces high-resolution, two-dimensional images and will be used for a wide range of educational, science and industry applications. Chemical analysis can also be performed. The purpose of these investigations was to get the information about the composition of the C-S-H phases and some details of the nanostructure of the C-S-H phases. [ABSTRACT FROM AUTHOR]

Lay description Tricalciumsilicate is the major component of the Portland cement clinker. Hydration of Tricalciumsilicate is decisive in influencing the properties of the resulting material. This is due to its high content in cement. The reaction with water is termed "hydration". This involves many different reactions, often occurring at the same time. As the reactions proceed, the products of the hydration process gradually bond together and other components of the concrete, to form a solid mass. The mechanism of the hydration of Tricalciumsilicate is very complicated and not yet fully understood. There are different models that describe the hydration of Tricalciumsilicate in various ways. In this work for a better understanding of hydration mechanism, the hydrated Tricalciumsilicate was investigated by using the transmission electron microscope. Transmission electron microscope is a very powerful tool for material science. A high energy beam of electrons passes through a very thin sample, and the interactions between the electrons and the atoms can be used to observe the structure of the material and other features in the structure. Transmission electron microscope can be used to study the growth of layers and their composition. Transmission electron microscope produce high-resolution images and will be used for a wide range of educational, science and industry applications. Chemical analysis can also be performed. For the investigations were used an FEI Talos F200x with an integrated Energy Dispersive X-Ray Spectroscopy System. FEI Talos F200X combines outstanding high-resolution Scanning Transmission Electron Microscope and Transmission electron microscope imaging with energy dispersive X-ray spectroscopy signal detection, and 3D chemical characterization with compositional mapping. The purpose of these investigations were to get the information about the composition of the Calcium Silicate Hydrate phases and some details of the nanostructure of the Calcium Silicate Hydrate phases. [ABSTRACT FROM AUTHOR]