Capillary imbibition or water uptake tests are practical and they satisfactorily describe the performance of cementitious materials. Most of these tests are performed for a short period (<1 week), however, additional water uptake has been documented after the water front has covered the total height of samples. This process occurs at a very low rate and it could provide further information about the pore structure. We investigated long-term capillary imbibition in mortar and concrete with and without supplementary cementitious materials. This paper reports our results and results from literature, and proposes a phenomenological description of the process. The trends observed from long-term tests are consistent across different water to cementitious material ratios, binder types, fine and coarse aggregates, curing ages, and conditioning regimes. Long-term measurements reveal primary and secondary periods of capillary imbibition that are well described by a bi-linear relationship with the fourth root of time.

毛细管吸水或吸水测试很实用，可以令人满意地描述胶凝材料的性能。这些测试大多数都是在短时间内（<1周）进行的，但是，在水位覆盖了样品的总高度之后，有更多的吸水量被记录下来。该过程发生的速率非常低，它可以提供有关孔结构的更多信息。我们研究了在有和没有辅助胶结材料的情况下，砂浆和混凝土中的长期毛细吸收现象。本文报告了我们的结果以及来自文献的结果，并提出了该过程的现象学描述。长期测试中观察到的趋势在不同的水与水泥材料的比例，粘合剂类型，细骨料和粗骨料，固化年龄和调理体系之间是一致的。