Long-term moisture transport in high performance concrete
Long-term moisture transport in high performance concrete
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DOI：
10.1007/bf02480357
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发表时间：
2002-10
影响因子：
3.8
通讯作者：
L. Nilsson
中科院分区：
文献类型：
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作者：
L. Nilsson
水分对高性能混凝土的大量粘合和运输过程具有决定性作用，影响各种环境中的耐久性、收缩和性能。以胶凝材料、外加剂和水胶比为参数，对20个混凝土拌合物的水分传输特性进行了为期7年的试验研究。采用倒置玻璃杯法测定了混凝土圆盘的稳态流动，结果表明，随着水胶比的降低，硅灰掺量的增加，尤其是与粉煤灰掺量的增加，混凝土圆盘的水分扩散系数降低，当w/B小于0.40时，扩散系数在4年后继续下降。与普通混凝土相比，高性能混凝土的水分扩散系数对水分的依赖性要小得多，这意味着高性能混凝土结构的稳态水分分布几乎是线性的。浸水高性能混凝土中的长期水分分布将受到自干燥的影响，因为水流量非常小。
Moisture is decisive for a large number of binding and transport processes in high performance concrete affecting the durability, shrinkage and performance in various environments. An experimental study on the moisture transport properties of 20 concrete mixes was made during seven years, with type of binder, additives and waterbinder ratio as parameters. An upside-down glass cup method was used to obtain the steady-state flow through concrete discs.The moisture diffusion coefficient decreases with a lower water-binder ratio, increasing amount of silica fume, especially when combined with fly ash and it continues to decrease also after four years for w/B lower than 0.40. The moisture diffusion coefficient is much less moisture dependent for HPC than for normal concrete, which means that steady-state moisture profiles through HPC structures will be almost linear. Long-term moisture profiles in submerged HPC will be affected by self-desiccation for a very long time because of the extremely small moisture flow.