STP906: X-Ray Permeability of Corrosion Products as a Measure of the Rate of Corrosion of Rebars and of Prediction of Concrete Cracking

    Skoulikidis, T
    Professor, Dr. of chemical engineering, and assistant professor, National Technical Engineering, Athens,

    Marinakis, D
    Professor, Dr. of chemical engineering, and assistant professor, National Technical Engineering, Athens,

    Batis, G
    Professor, Dr. of chemical engineering, and assistant professor, National Technical Engineering, Athens,

    Pages: 10    Published: Jan 1986


    Abstract

    Normalized reinforced specimens were placed in 3.5% circulating sodium chloride (NaCl) solution (25°C) under a +850-mV anodic charge. At several time intervals on all of these specimens X-ray radiographies were taken focused on the rebars and on the concrete, and the specimens were placed again in the solutions. Measurements were taken for four months. Because of the direct lowering of the pH in the interface rebar-concrete, the pure electrochemical character of the corrosion overcomes the carbonation, and the concrete cracking is mainly and directly caused by the formation of corrosion products. It was also proved by electron probe micro-analysis (EPMA), a solid state diffusion of Fe2+ through the concrete. It was found that during the exposure the permeability of X-rays in the corrosion products decreases because of mechanical stresses. It is possible to follow the evolution of the corrosion products by X-rays and from their permeability to predict the cracking of the concrete caused by the formation of corrosion products.

    Keywords:

    rebars (reinforcing bars), corrosion, X-rays, permeability, X-ray permeability, crack prediction, solid state diffusion of Fe, 2+


    Paper ID: STP18306S

    Committee/Subcommittee: G01.11

    DOI: 10.1520/STP18306S


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