|
Title |
Evaluation of Mechanical Properties for Setting of Cementitious Materials Using Air-Coupled Ultrasonics
|
|
Authors |
홍진영(Jinyoung Hong) ; 박주혜(Joohye Park) ; 최하진(Hajin Choi) |
|
DOI |
https://doi.org/10.4334/JKCI.2022.34.1.051 |
|
Keywords |
비접촉 초음파; 응결; 탄성계수; 관입 저항침 시험; 콘크리트 air-coupled ultrasonics; setting; modulus of elasticity; pin penetration test; concrete |
|
Abstract |
In this study, the generation of leaky-Rayleigh waves using air-coupled ultrasonics was theoretically verified and the corresponding mechanical properties of cementitious materials were experimentally evaluated. First, analytical solutions for leaky- Rayleigh waves were derived in the joint-half space based on elastic wave theory. As a result, the velocity difference between Rayleigh wave and leaky-Rayleigh wave was found to be less than 0.2 %. Also, the correlation between dynamic modulus of elasticity and leaky-Rayleigh wave was suggested. In experiment, penetration resistance test results were problematic, varying depending on the size of samples and operations. On the other hand, air-coupled ultrasonic test confirmed that the initiation of Rayleigh and leaky-Rayleigh waves was identical. The elastic modulus of the setting in cementitious materials can be defined as a range of 5~8 GPa based on the suggested equation. The proposed air-coupled ultrasonic method not only has great potential for experimental convenience in the field, but also defines mechanical properties of the setting in cementitious materials.
|