Evaluation of Rebar Corrosion without Oxide film in RC by Acoustic Emission and Half-Cell Potential Method
Rebar corrosion problems of reinforced concrete (RC) due to salt attack have been widely reported throughout the world.In Japan, a lot of non-destructive inspection methods for rebar corrosion have been investigated the issue.For instance, the electrochemical method is actively used on-site.On the other hand, the authors applied AE (Acoustic Emission).method to the evaluation of rebar corrosion and proposed a hypothesis that the elastic waves are generated when the oxide film exfoliates from on the surface of the rebar.This means that the onset of corrosion might be detected by AE method.However, the hypothesis has not been validated yet.Based on the above, the authors aim to develop a hybrid-NDT which combined electrochemical method and AE method in this study.In this study, the dimension of RC specimen was 100×100×400mm and a rebar without the oxide film was embedded in concrete.Six AE sensors were placed at the surface of each specimen and two probes were set to measure the half-cell potential.A cyclic wet and dry test was conducted and both an AE hit and half-cell potential were continuously monitored every 10 minutes.A lot of AE hits which included some noises were detected from the beginning of the measurement.Also, the half-cell potential of the rebar shifted to negative after the 186 days concrete immersion, and this suggests the corrosion initiation.From the results of the 3D location analysis, some AE events occurred around the rebar.This can be evaluated with high performance by the combination of AE method and half-cell potential measurement.
Acoustic Emission AE characteristic Corrosion Half-Cell Potential Location analysis
Y.Yasuda M.Yokota T.Fukuyama Y.Kawasaki
Graduate School of Science and Technology, Ritsumeikan University, Shiga, Japan Yokota DPC Laboratory, Kagawa, Japan Department of Architecture and Urban Design, Ritsumeikan University, Shiga, Japan Department of Civil and Environmental Engineering, Ritsumeikan University, Shiga, Japan
国际会议
福州
英文
757-763
2018-11-04（万方平台首次上网日期，不代表论文的发表时间）