Abstract
In evaluation of imperfectly grouted part of tendon ducts in PC members, the influences given on vibration of sheath were investigated using a mechanical and a magnetical input method. These methods control the parameter of impact and generate elastic waves with high repeatability and accuracy. For this purpose, the specimens having a number of holes penetrating to the sheath were used, which enabled to observe the vibration directly on the sheath. As a result, it was found that the penetration and reflection properties of elastic wave at the sheath changed due to the existence of void in the sheath. Next, by defining “wave energy” of the detected signals at the grouted part and the ungrouted part, the detection capability of ungrouted part was made clear under the available placement of impact and detection. Thus, it was found that the magnetical input method has the larger detection capability of ungrouted part than the mechanical input method. By considering application of these methods at the concrete structures in use, a new inspection flowchart of evaluating ungrouted part was proposed.
