Experimental Study on Applicability of Measuring Method of Chloride Content using Electromagnetic Wave in Reinforced Concrete Structures

摘要

A definite understanding about any corrosion of reinforcement is very difficult unless corrosion induced cracks appear on the surface. Thus, in order to detect chloride-induced corrosion at an early stage, chloride content within concrete needs to be investigated using cores drawn from the RC structure, and carrying out chemical analysis. Now, drawing cores could be structurally unacceptable, damage the reinforcement and the repair could be aesthetically unappealing, only very limited sampling can actually be carried out. In addition, drawing cores to estimate the chloride content in concrete could not make it possible to study the changes in chloride content over time (at exactly the same place). On the other hand, it has been obtained from laboratory tests under limited conditions that chloride content within concrete has could be almost estimated by using electromagnetic waves as one of the non-destructive tests. However, as all specimens have be added sodium chloride during the mixing of concrete in the laboratory tests, the experiments have been not carried out to estimate chloride content using specimens permeated chlorides from the concrete surface after placing. Since experiments to estimate the chloride content in concrete using electromagnetic waves have been carried out to apply existing concrete structures to be a premise, the convenient measuring instrument that the frequency was fixed was used. However, it should be considered that excellence frequency may be changed by water content and chloride content in concrete.