Study on Surface Permeability of Concrete under Immersion

Materials

Jun Liu¹  Feng Xing¹  Biqin Dong¹  Hongyan Ma² 

[1] Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil Engineering, Shenzhen University, Shenzhen 518060, China; E-Mails:;Department of Civil and Environmental Engineering, the Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong

关键词: concrete;    immersion;    calcium hydroxide;    surface permeability;    pore structure;   

DOI  :  10.3390/ma7020876

来源: mdpi

【 摘 要 】

In this paper, concrete specimens are immersed in ultrapure water, to study the evolutions of surface permeability, pore structure and paste microstructure following the prolonging of immersion period. According to the results, after 30-day immersion, the surface permeability of concrete becomes higher as compared with the value before immersion. However, further immersion makes the surface permeability decrease, so that the value measured after 150-day immersion is only half that measured after 30-day immersion. The early increase in surface permeability should be mainly attributed to the leaching of calcium hydroxide, while the later decrease to the refinement of pore structure due to hydration. The two effects work simultaneously and compete throughout the immersion period. The proposed mechanisms get support from microscopic measurements and observations.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland