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STUDY OF ELECTROCHEMICAL CHLORIDE EXTRACTION AS A NON-DESTRUETIVE REPAIR METHOD: PART I. DISCRETE TEST SAMPLES.

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The representative parameters of ECE and the side effects were determined experimentally. The experimental program investigates chloride and alkali concentration, chloride removal efficiency, transference number, half-cell potential and possible bond strength degradation which is determined by pull-out test. Test variables were percentage of chloride concentration to mass of cement (i.e., 0%, 1%, 1.5% and 2%) and duration of application of constant electric current (i.e., 2, 4, 6 and 8 weeks). Tests results indicate that chloride concentration around rebars reduces to the threshold concentration level of about 0.4 after 6 to 8 weeks of treatment. Half-cell potential shows that corrosion activities of the steel reinforcement were stopped 8 weeks after the end of treatment. Chloride removal efficiency is hardly reached to 60% after 8 weeks of ECE treatment. Bond strength in specimens with and without transverse reinforcement was reduced by 30-44% and 19-27% at the end of the treatment, respectively. Bond strength in specimens with and without transverse reinforcement was increased by 10-16% and 8-10%, 8 weeks after end of treatment, respectively. Test results on a reinforced concrete slab will be presented in the subsequent paper.

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