This European Standard, a part of the BS EN 12504 series, specifies a method for the determination of the velocity of propagation of pulses of ultrasonic longitudinal waves in hardened concrete, which is used for a number of applications.
A pulse of longitudinal vibrations is produced by an electro-acoustical transducer held in contact with one surface of the concrete under test. After traversing a known path length in the concrete, the pulse of vibrations is converted into an electrical signal by a second tranducer and electronic timing circuits enable the transit time of the pulse to be measured.
Annexes to this standard provide information on the determination of pulse velocity, factors influencing pulse velocity measurements, and the correlation of pulse velocity and strength.
BS EN 12504-4:2004 gives guidance on testing fresh concrete, hardened concrete and concrete in structures.
It specifies a method for the determination of the velocity of propagation of pulses of ultrasonic longitudinal waves in concrete.
The measurement of pulse velocity can be used for the determination of the uniformity of concrete, the presence of cracks or voids, changes in properties with time and in the determination of dynamic physical properties.