STP1180: A Theoretical Model of Water Penetration into Concrete Masonry Units

    Barkofsky, PR
    Research Engineer and Technical Supervisor, W. R. Grace & Co. - Conn., Cambridge, MA

    Driscoll, ME
    Research Engineer and Technical Supervisor, W. R. Grace & Co. - Conn., Cambridge, MA

    Pages: 13    Published: Jan 1993


    Abstract

    The effect of water damage on masonry walls is well known, and a variety of test methods have been developed to measure the susceptibility of masonry to the forces that drive water within wall systems. Several test methods and their correlation to these forces are discussed in a separate paper.

    This paper offers a qualitative model of water penetration that relates the inherent properties of masonry and the external conditions to which it is exposed to its ability to resist water leakage.

    Darcy's equation of flow through porous media describes the resistance to flow offered by the tortuous networks of channels in a permeable material and quantifies the force necessary to overcome this resistance. Considering the environmental conditions that a wall is exposed to, we can modify Darcy's equation and use it to characterize masonry's propensity for water transmission driven by the forces of rain velocity, capillary pressure, differential air pressure, and gravity based on masonry material properties. In addition, with data typical of environmental exposure characteristics, the singular and additive effects of these forces can be computed and compared.

    Keywords:

    water penetration, water infiltration, theoretical model, masonry, Darcy's law, permeability, wind-driven rain, capillary pressure, air pressure, gravity


    Paper ID: STP19622S

    Committee/Subcommittee: C15.03

    DOI: 10.1520/STP19622S


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