A FUNDAMENTAL RESEARCH ON THE DETECTION METHOD OF SHEAR DAMAGE OF RC BEAM BASED ON THE LOCAL OUTLIER FACTOR METHOD

Abstract

For the purpose of confirming the applicability of the local outlier factor method (LOF) in non-destructive inspection to detect shear damage inside reinforced concrete beams，an experimental study of RC beam specimens was conducted. When shear loading was performed with a small load that did not cause visible shear cracks due to shear damage inside the RC beam specimen, the time history of the hitting sound and the concrete surface vibration acceleration at the time of hitting with a hammer was recorded. We tried to judge the damage by the judgment method based on LOF using the spectrum obtained by Fourier transforming the recorded time history. As a result, it was confirmed that the presence or absence of shear damage could be determined using the proposed method, maintaining a true negative rate and a true positive rate of approximately 90%. In addition the threshold setting range required for LOF was discussed..