Damage detection in concrete using nonlinear signal attenuation ultrasound

In this paper concrete damage detection is experimentally studied investigating the effectiveness of applying ultrasonic wave atte-nuation. The study is focused on nonlinear ultrasonic evaluation of standard size concrete cubes subjected to compression at different loading levels inducing distributed damages. At each damage level ultrasonic attenuation with different power levels was measured. The attenuation changed with increasing damage and power levels for all specimens. The damage is evaluated by analyzing the reduction in amplitude of the ultrasonic waveforms, transmitted through the specimen during the test. It is shown that ultrasonic attenuation has higher sensitivity to cracking in concrete at the initial stages of damage, compared to the pulse velocity technique. It increases significantly as distributed damage in concrete increases. Detailed discussion on using wave attenuation as a measure of damage growth in concrete is presented.