Acknowledgement
이 논문은 2015년도 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구입니다(No.2015R1A5A1037548).
The non-destructive method using ultrasonic waves has been applied in many studies due to its low damage to the structure and its simple evaluation method and high precision. On the other hand, if the concrete is subjected to a high-temperature, the mechanical properties may be deteriorated due to the micro-crack network and the damage may be severe depending on the strength of the concrete. Therefore, this study attempts to evaluate the fundamental wave behavior of different strength ranges using the ultrasonic non-destructive method for concrete that has been subjected to high-temperature. As a result, the relative power of the fundamental wave was decreased as temperature increase. And it was confirmed that the 2nd and 3rd harmonics were generated at 110 MPa. However, to check the 2nd, 3rd harmonics 110 MPa or less, there is a need for further research considering the ultrasonic output, the output of the sender and receiver, and the appropriate frequency accordingly.
이 논문은 2015년도 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구입니다(No.2015R1A5A1037548).