PROPAGATION OF RAYLEIGH-WAVES IN CONCRETE

The conventional ultrasonic method of checking surface properties of c oncrete is subject to large errors due to low signal amplitude generat ed by normal pressure wave transducers. This paper illustrates a serie s of measurements using an ultrasonic goniometer, on mortar, concrete and rock samples. A 2.25 MHz 10 mm-diameter immersion transducer was u sed to propagate Rayleigh waves in a sample surface by a corner reflec tion method. The experimental results show a significant change in vel ocity and amplitude of the Rayleigh wave, with different concrete qual ity. This means that it is possible to use a pure Rayleigh wave to che ck the quality of concrete surfaces or sub-surfaces as a better altern ative to the conventional method.