2018 Volume 29 Pages 87-100
This research aims to identify defective areas inside existing concrete structures based on impact response characteristics. An impact response test was conducted on small test slabs containing a number of artificial defects by using an impulse hammer with force sensor and an acceleration sensor. Various properties of defects in terms of their influence on impact response characteristics were investigated, and the frequency response function (transfer function) was determined to be an important index of evaluation of defective areas. Evaluation of defective areas with minimum diameter of 200 mm and maximum depth of 70 mm was carried out by applying frequency response function data to Self-Organizing Map (SOM). Further, this method was applied to existing concrete structures and it was shown to be effective for evaluation of defective areas inside existing concrete structures.