Ultrasonic Pulse Velocity Test

Principle of the test : The velocity of a wave passing through an elastic medium is a function of the modulus of elasticity of the material & its density .

THeory : Pulse velocity increases , compressive strength increase .

The technique consists of measuring the time of travel of an ultrasonic wave generated throught the concrete .

• The time taken for the pulse to travel between the initial onset & its reception is measured electronically . 
• The average velocity of wave propogation or pulse velocity is determined by dividing the known path length between the transducer by the time taken . 
• Pulse velocity = distance travelled ( km ) / time ( s) 
• Travel Time : Time taken for pulse to travel between the 2 transducers . 
• Distance travelled : Path between 2 transducers . 
• The main advantages of this method are that it is totally non-destructive , quick to operate & reflects the quality of the interior of the concrete member . 
• Useful in obtaining a considerable number of readings in a relatively short time for the assessment of uniformity of hardened concrete .