STP691

    Theoretical Air Pollution and Climate Effects on Materials Confirmed by Zinc Corrosion Data

    Published: Jan 1980


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    Abstract

    Observed effects of pollution level, relative humidity, temperature, wind velocity, and surface geometry are explained using diffusion theory and thermodynamics. Many materials readily react with pollutants, thus, the rate controlling step is the flux of pollutants to the surface. In such cases, dose-response damage coefficients can be calculated from turbulent diffusion theory. Electrochemical corrosion of metals occurs when the surfaces are wet. A surface will become wet when the relative humidity adjacent to the surface exceeds a value in equilibrium with a saturated solution of a corrosion product or contaminant on the surface. Based on these considerations, the consistency of predictions with observed effects suggests that air pollution damage functions can be calculated for a variety of material surfaces for which data are not available.

    Keywords:

    corrosion, zinc, galvanizing, air pollution, climatic factors, eddy diffusivity, mass flux, damage functions, durability, building materials


    Author Information:

    Haynie, FH
    Environmental engineer, Environmental Sciences Research Laboratory, Environmental Research Center, Environmental Protection Agency, Research Triangle Park, N.C.


    Paper ID: STP36057S

    Committee/Subcommittee: G03.02

    DOI: 10.1520/STP36057S


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