ABSTRACT
Reinforcement corrosion caused by the presence of chloride ions around the reinforcing bars has been identified as one of the major causes of deterioration of concrete structures The chlorides could find their way to concrete either as part of constituent materials when sea sand is used, or, by gradual permeation and diffusion as in the case of marine structures, or, cases where deicing salts are used to melt away snow on highways, etc. However, a definite understanding about any corrosion of reinforcement is very difficult unless corrosion induced cracks appear on the surface. In order to detect the deterioration caused by the chloride ions in an early stage, it is implemented generally to investigate chloride contents within concrete by carrying out chemical analysis using cores drawn from the RC structure. But, the method for carrying out to the chemical analysis using drawing cores not only gives damage partially to the concrete structure, but also is only to obtain result of analysis at the position of the drawn cores In addition, drawing cores to estimate the chloride contents in concrete could not make it possible to investigate the changes in chloride contents over time at exactly the same place.
