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Study on Surface Permeability of Concrete under Immersion
Jun Liu1, Feng Xing2, Biqin Dong3
1Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil Engineering, Shenzhen University, Shenzhen 518060, China. liujun@szu.edu.cn.
Materials (Basel, Switzerland)
|August 10, 2017
Summary
Concrete
Area of Science:
- Civil Engineering
- Materials Science
Background:
- Concrete durability is crucial for infrastructure.
- Understanding water-rock interactions is key to material performance.
Purpose of the Study:
- To investigate the impact of prolonged ultrapure water immersion on concrete's surface permeability, pore structure, and microstructure.
- To elucidate the competing mechanisms governing these changes over time.
Main Methods:
- Immersion of concrete specimens in ultrapure water for extended periods (up to 150 days).
- Measurement of surface permeability.
- Analysis of pore structure and paste microstructure using microscopic techniques.
Main Results:
- Surface permeability initially increased after 30 days of immersion.
- Permeability significantly decreased by 150 days, reaching half the 30-day value.
- Microscopic analysis supported the proposed mechanisms.
Conclusions:
- Early permeability increase is linked to calcium hydroxide leaching.
- Later permeability decrease results from pore structure refinement due to ongoing hydration.
- These opposing processes dynamically influence concrete's surface properties during water exposure.
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