Particle Distribution Characteristics and Hydration Mechanism of Cement-Based Paste Subjected to Mechanical Vibrations

Mechanical vibrations have a significant impact on the performance of cement-based materials in engineering. In this study, the particle distribution characteristics and hydration mechanism of cement-based paste during mechanical vibrations were clarified, including examination of hardened properties and thermodynamic modeling. X-ray fluorescence was used to determine the distribution of raw material particles. Differential thermal analysis was employed to characterize the in situ hydration process of paste. Thermodynamic modeling determines the dependency between raw material distribution and the corresponding hydration process. The results indicated that low-frequency vibrations extend the setting time and induce lower flexural strength of cement paste during early ages. Mechanical vibrations result in significant inhomogeneous distribution of element content, which was attributed to the difference in raw material composition. The hydration degree after mechanical vibrations decreased the pore-size distribution of hardened paste. The calculated particle distributions were inconsistent with the obtained hydration process and porosity development.