Compensation procedure for half-cell potential measurement

Non-destructive evaluation for corrosion of reinforcement is performed limitedly by the half-cell potential measurement. To compensate the measured potentials for reasonable corrosion estimation, theory of the half-cell potential is clarified and a modified boundary element method (BENI) analysis was developed. An applicability of the proposed procedure was examined by electrolytic tests of reinforced concrete slabs. By the modified BEM, the potentials at rebars were computed from the potentials measured at the concrete surface. The ASTM criterion for the potential values was applied to the estimation of corrosion. Good agreement was observed between the predicted corrosive region of the rebars and actually corroded region. In the case of the specimen with a cavity, it was found that the half-cell potential measurement misleads to more negative potentials than those of no cavity. It was noted that software development is so simple as to be readily implemented in a microcomputer. (C) 1997 Elsevier Science Ltd.