加振レーダ法によるRC 床版の水平ひび割れ検知への適用

抄録

It is well known that damaged RC deck slabs sometimes yield large horizontal cracks along mesh reinforced bars. As a repairing technique, the increasing thickness technique of deck slabs has often been applied to the damaged RC deck slabs, which can delay the degradation progress of deck slabs. However, the re-degradation of the repaired RC deck slabs is becoming apparent in recent years. In this paper, the vibro-radar method was used to detect a horizontal crack in deck slabs which can non-destructively estimate the vibration displacement of the rebar forced to vibrate by the excitation coil on the concrete surface. Through experimental results, it is clear that a RC test piece with an imitated crack increases in vibration displacement by 30% comparing to that without any defect. This suggests that the vibration displacement of a rebar depends on the adhesion of a rebar to concrete.