Simple modeling method of corrosion degree in rebar existing the cavity caused by the expansive stress in concrete due to the corrosion in rebar in RC structure is investigated. Employing the thermal on concrete surface by the thermography, heat stored in reinforcing steel-bar (rebar) due to electro-magnetic heating is applied to estimate qualitatively the thickness of cavity and the corrosion degree.
The thickness of corroded layer in rebar is identified by the difference of the increased value of temperature on concrete surface between the measured value and the analyzed value assumed the rebar as non corroded state. On the other hand, the thickness of cavity is identified by the rate of the temperature increase on the concrete surface. An applicability of the analysis is demonstrated by the comparison between the analyzed and those measured value.
