A Study on Factors Influencing P-wave Velocity of Concrete

콘크리트의 P파 속도에 영향을 주는 인자에 관한 연구

Recently, non-destructive tests are getting popular in evaluating concrete properties without braking specimens. Among several NDT methods, P-wave velocity measurement technique has been widely used to evaluate the stiffness and strength of concrete. The purpose of this study is to investigate factors influencing P-wave velocity measured by impact-resonant method and ultrasonic pulse velocity method, such as moisture content of concrete, existence and size of coarse aggregates, sensor and sampling rate. Test results show that rod-wave velocity measured by impact-resonant method and ultrasonic pulse velocity are significantly affected by the moisture content of concrete, i.e., the lower moisture content, the lower velocity. Moisture content influences rod-wave velocity stronger than ultrasonic pulse velocity. Rod-wave velocity is faster in concrete than in mortar and is also faster in concrete containing small size aggregates. Sensor and sampling rate have little influence on velocity.