INFLUENCE OF TEMPERATURE AND RELATIVE HUMIDITY ON ELECTROCHEMICAL MEASUREMENT VALUES OF STEEL BARS IN CONCRETE

Abstract

As our country surrounded on four sides by the ocean, the establishment of maintenance system against chloride attack for port and harbor facilities is a serious challenge in Japan. Port and harbor facilities are inspected and evaluated primarily visually in cooperation with simple non-destructive tests such as hammering tests, but inspection and examination technologies must be improved so that proactive maintenance measures should be taken.
This research was focused on the application of electrochemical monitoring for the proactive maintenance of concrete members due to chloride attack under environmental impacts as a part of efforts to improved technologies for the inspection and examination of steel corrosion in concrete members. In particular, it was a study of the impacts of temperature and moisture content on electrochemical measurement values and on the interrelationships between various electrochemical measurement values, to identify challenges to the establishment of judgment for degree of chloride attack deterioration in reinforced concrete members. Half-cell potential, polarization resistance and specific electro resistance display behaviors that differ according to each environment, and discontinuous measurements using independent indices can result in incorrect judgments of concrete members. Therefore, it is thought possible to perform high precision inspections and evaluation by continuous monitoring considering each environmental impact. In marine environments, the temperature and moisture content inside a single concrete member vary greatly, so further study including measurement locations, quantities and frequencies of electrochemical corrosion monitoring will be performed in the future.