Research to Develop Non-Destructive Testing (NDT) Methods to Evaluate Large Anchor Bolts.
Reclamation has a number of dams where large anchor bolts, up to three inches in diameter and over ten feet long, are used to support large spillway gates. Many of these anchor bolts were placed over 50 years ago. Currently, there is no way of determining the load carrying capacity of these bolts.
We are forming a Second Party Evaluation Program. This program will provide researchers and funding agencies with an unbiased evaluation of NDT methods to evaluate large anchor bolts. The first step of the Second Party Evaluation Program is determining the most likely failure modes, including types and causes of corrosion, probable loads, and locations of failures. The next step will be to design a testing program, and build a series test frames based on the likely failure modes.
Need and Benefit
Existing methods for evaluating large anchor bolts cast in concrete consist of visual inspection, and a "lift-off" test. The visual inspection does not provide us with any information on the bolt buried in the concrete. A "lift-off" test is destructive in nature, destroying the bond between the anchor bolt and the concrete.
Contact the Principal Investigator for information about these documents.