Porosity and liquid absorption of cement paste

M. Krus, Kurt Kielsgaard Hansen, H. M. Kunzel

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    The moisture behaviour of building materials exposed to the natural climate is largely dependent on their water absorption. In contrast to most building stones, cementitious materials like concrete do not exhibit a water absorption that is proportional to the square root of time. There must be a slowing-down effect which is related to water because the absorption of organic liquids, such as hexane, is quite normal. Measurements of the porosity of hardened cement paste determined by helium pycnometry and water saturation show that water molecules can enter spaces in the microstructure which are not accessible to the smaller helium atoms. Considering the results of dilatation tests both before and after water and hexane saturation, it seems possible that a contraction of capillary pores due to moisture-related swelling of the cement gel leads to the non-linear water absorption over the square root of time.
    Original languageEnglish
    JournalMaterials and Structures
    Volume30
    Issue number7
    Pages (from-to)394-398
    ISSN1359-5997
    Publication statusPublished - 1997

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