Evaluation for RC specimen damaged from rebar corrosion by acoustic emission technique

摘要

Recently, early deterioration of reinforced concrete (RC) has been reported and is becoming a critical issue among many countries. One of these problems is the corrosion of reinforcing steel bars (rebar). In 2011, many infrastructures made by concrete were immersed in sea-water by the tsunami that occurred in the wake of the Great East Japan Earthquake. As a result, it is predicted that the problems of rebar corrosion may further increase in future. In this research, we apply acoustic emission (AE) technique to evaluate the seismic capacity of the specimens which was subjected to influence of rebar corrosion. Then, the result of AE activities and parameter analysis are compared with such mechanical properties as flexural capacity, toughness, and quantity of energy absorption. Furthermore, the corrosion state of the acceleration stage was compared to the dormant stage. It is confirmed that mechanical properties at the acceleration stage decrease from the dormant stage, and AE activities are correlated with the seismic capacity of the specimens.