STP1246: A Capillary Suction Model for Concrete Masonry and Its Application to Integral Water-Repellent Masonry

    Karkare, MV
    Senior Research Engineer and Research Supervisor, W. R. Grace & Co. - Conn., Cambridge, MA

    Walloch, CT
    Senior Research Engineer and Research Supervisor, W. R. Grace & Co. - Conn., Cambridge, MA

    Pages: 21    Published: Jan 1996


    Abstract

    Capillary suction plays a major role in water transport and redistribution after water comes in contact with the face of masonry structures. This paper proposes a new test method to characterize the capillary suction properties of concrete masonry units.

    Water capillary suction data for both concrete block and Type S portland cement-lime mortar containing different amounts of integral water-repellent (IWR) admixtures are presented. An empirical two-parameter power law model is proposed to fit the test data. The effect of IWR admixture dosage rates on the model parameters and water repellent characteristics of the masonry components is discussed. The significance of the parameter values is also explained. The testing showed that as IWR dosage rate increases, capillary suction decreases. At commonly used IWR admixture dosages, the reduction in capillary suction of the masonry exceeded 80% at 24 h. It was also demonstrated how the model parameters can be used to determine the optimum admixture dosage range.

    Keywords:

    capillarity, capillary pressure model, capillary suction, wicking, integral water repellents, admixtures, water penetration, masonry test method, concrete masonry


    Paper ID: STP18208S

    Committee/Subcommittee: C15.03

    DOI: 10.1520/STP18208S


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