Nanostructure and Chemical Composition of Cement-Based Materials: Testing and Characterization Based on Solid State NMR and Electron Microscopy
With the research scale of materials science gradually changing from macro to micro, the research on the nanostructure and chemical composition of cement-based materials has become a hot research topic. Although the traditional research methods are very mature, and have also achieved good application results in the exploration of microscopic analysis, structural distribution, composition analysis, and morphology analysis, but for the specific cement hydration mechanism and the hydration of important constituent materials. The structure of Calcium Silicate Hydrate (CSH) gel is still not fully understood. Therefore, solid magnetic resonance and electron microscopy were used to test and characterize the nanostructure and chemical composition of cement-based materials. Firstly, the solid-state NMR technique was used to study the variation law of hydration products, and then the hydration degree was quantitatively described according to the research results. By comparing the analytical method of this paper with the traditional hydration degree characterization method, it is verified that the method has certain rationality and feasibility. Finally, the microscopic morphology of C-S-H was studied by electron microscopy. The C-S-H with C/S of 1.5 was found to be a fibrous amorphous material with a length of several tens of nanometers to several hundred nanometers. The experimental results show that the solid-state NMR and electron microscopy testing and characterization methods are of great significance for the study of the nanostructure and chemical composition of cement-based materials.