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Microstructural Damage Mechanism of Fresh Cement paste under Formation Water Conditions
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DOI:10.1016/j.cemconcomp.2026.106658.png)
Abstract
En 中文
This study established a formation water seepage simulation method to study the influence of formation water on fresh cement paste during the setting stage and to explore the mechanism underlying the microstructural damage of the paste. The results showed that during the hydration process, the cement clinker dissolved, releasing Ca2+, SiO44-, and other ions, which enhanced the chemical potential difference (CPD) between the pore solution in the cement and formation water. Moreover, the coupling effects of the CPD and formation water seepage caused a “replacement–migration” of the pore solution by the formation water, altering the setting process of the paste. When the hydration entered the acceleration period, the microstructure of the cement paste changed from “suspension–dispersion” to “gel–grid”. Although the structure and anti-water-intrusion ability of the cement paste were improved, the pore solution in the paste was still replaced–migrated. Concurrently with the “replacement-migration” effect, CO32- in the formation water reacted with Ca2+ in the pore solution, forming CaCO3 precipitate, which adsorbed on the surface of the hardened cement paste. However, the “replacement–migration” effects were significantly more pronounced than the CaCO3 adsorption rate, resulting in a micro-gap at the interface between the core and hardened cement paste. The degree of damage to the hardened cement paste increased with increasing core permeability, injection pressure, temperature, and water–cement ratio. These findings provide experimental support for the investigation of anti-water-intrusion materials and the design of durable cement-based materials suitable for high-water-cut environments.
Keywords:
formation water
cement paste
microstructural damage
seepage simulation
hydration process
Journal
IF:
13.1
Papers:
5.4K
Citations:
5.1W
