Non-destructive test is an scatheless inspection for the self-drilling anchor bar. This small instrument head is equipped with piezoelectric crystal sensor. Put the instrument probe against the exposed end of the self-drilling anchor bar, and the sensor can transmit the elastic wave generated in the small instrument to bar.
The propagation speed of the wave depends on the length of the self-drilling anchor bar, the condition of mortar and the combinative state, so the wave is passed along the anchor rod in different speed. Then the signal returned to the sensor to analyze the length of the self-drilling anchor bar, the combinative state of the cement paste and the anchor bolt or the wall of holes after the managing the signal returned. Besides, it can also analyze whether the contract between the mechanical anchorage devices and wall of the holes meet the requirements and stress. Finally, it can be concluded that whether the quality of the self-drilling anchor bar is good.
This kind of the test is widely applied to the self-drilling anchor bar because it belongs to wholly grouted bolts. Relating to this kind of the anchor bolts. When the self-drilling anchor bar was filled with cement paste close to the head only about 20 cm, it will be difficult to find its problems using methods tensile experiments.