Study on Surface Permeability of Concrete under Immersion.
Study on Surface Permeability of Concrete under Immersion.
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浸泡混凝土表面渗透性研究
DOI：
10.3390/ma7020876
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发表时间：
2014-01-28
期刊：
影响因子：
--
通讯作者：
Pan D
中科院分区：
文献类型：
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作者：
Liu J;Xing F;Dong B;Ma H;Pan D
本文将混凝土试件浸泡在超纯水中，研究其表面渗透性、孔结构和浆体微观结构随浸泡时间的变化规律。结果表明，浸泡30d后，混凝土的表面渗透性较浸泡前有所提高。然而，进一步浸泡会使表面渗透率降低，因此浸泡150天后测得的值仅为浸泡30天后测得的值的一半。早期表面渗透率的增加主要归因于氢氧化钙的淋溶，而后期的下降主要归因于水化导致孔结构的细化。这两种效果同时起作用，并在整个沉浸期内相互竞争。提出的机制得到了微观测量和观察的支持。
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.