Experimental study reveals distinct acoustic frequency and amplitude thresholds in concrete walls, suggesting a reliable non-destructive method for detecting structural hollowing defects.
Key Points
To develop and evaluate an efficient, non-destructive method for detecting hollowing defects in concrete walls using the acoustic response generated from standardized knocking.
Conducted standardized knocking tests on concrete walls to record acoustic response signals from both hollowing and intact sections.
Performed time-domain waveform evaluations and frequency-domain spectral analyses to identify differential acoustic characteristics.
Dominant frequencies in hollow sections were distributed between 1650 Hz and 1750 Hz, whereas non-hollow areas concentrated between 1300 Hz and 1500 Hz.
Absolute peak amplitudes in hollow regions ranged from 40 mV to 50 mV, compared to 10 mV to 20 mV in intact regions.