철근 유무에 따른 콘크리트 코어드릴링 소음 신호의 주파수특성 비교 분석

초록

Core drilling in reinforced concrete (RC) carries risks of unexpected steel rebar contact, yet real-time detection methods remain limited. This study compares the acoustic noise characteristics of RC and non-reinforced concrete(NC) during core drilling to identify frequency-domain signatures associated with rebar presence. Drilling experiments were conducted on both specimen types using a 105 mm diamond-tipped core drill bit, with noise recorded at 48 kHz. Signals were analyzed via power spectrum density estimation, one-third octave band analysis, and spectrogram visualization across three drilling stages started at the steel contact time: initial, intermediate, and final. RC produced average noise levels approximately 3.3 dB higher than NC with greater variability. In the initial stage, RC showed markedly elevated energy in the 1 3 kHz band, up to 7 dB higher than NC at 4 kHz, attributed to metallic resonance from rebar tool contact. The results indicate that rebar-induced acoustic features are most prominent during rebar cutting stage, supporting the feasibility of acoustic-based rebar detection.

키워드