ICONE23-1899 DEVELOPMENT OF NON-DESTRUCTIVE INSPECTION TECHNIQUE FOR ADHESIVE ANCHOR BOLTS USING AE SENSOR : (1) EXPERIMENTAL APPROACH

Abstract

Post-installed adhesive anchor bolts are commonly used on all types projects, ranging from standard buildings to bridges and nuclear power plants. They are faster to install, generally considered to be stronger, more flexible, easier to use and more reliable in majority of applications at ambient temperatures. They are exposed to varying and diverse environmental conditions which are significant successfully to make connections to concrete structures for many years. With the failure of adhesive anchors in the Boston I-90 Tunnel Project, the use of these types of anchors has been called into question in America. On the other hand, also in Japan, a section of the Sasago tunnel's suspended concrete ceiling with adhesive anchor bolts became detached from the tunnel roof and fell onto the vehicles, 2012. In order to maintain the safety and reliability of concrete structures such as nuclear plants on higher level over a long period time, we developed a new non-destructive inspection system of adhesive anchor bolts based on hammering tests using AE (acoustic emission) sensor. By adjusting the amount of resin of adhesive anchors, the mockup anchors with poor construction quality was made on concrete blocks and mockup experiment was carried out to evaluate performance of this inspection system. As a result of the mockup experiment, peak frequency of signal obtained from AE sensor shifted to lower frequency as the amount of resin decreased. In this mockup experiment, it was confirmed that our developed inspection system based on hammering tests using AE sensor had a large potential to evaluate adhesive anchor bolts.