Rotary Hammering Method for Detecting Defects in Concrete Structures

Abstract

A hammering method is most commonly used to detect defeats in concrete structures. Though this method is relatively simple, the detection results depend upon the subjective sense of the inspector. In this study, we use a hammering test using a rotary hammering device instead of a conventional test hammer to ensure detection of defeats. The impact sound is measured above each hammering point while the rotary device is driven. The measured sounds at the healthy parts and the defective parts are compared in the time and frequency domain. From the time wave forms and the frequency spectra of sound pressure, there is clear difference between the healthy parts and the defective parts under a suitable hammering condition.