| 摘要 |
PROBLEM TO BE SOLVED: To simply measure the consistency of asphalt by measuring the sound velocity of longitudinal-wave ultrasonic waves at a specific frequency in the asphalt. SOLUTION: The sound velocity of longitudinal-wave ultrasonic waves at a frequency of 1 to 2.25 MHz in asphalt is measured. The longitudinal-wave ultrasonic waves refer to waves whose vibrating direction is identical to the advance direction of ultrasonic waves. This measuring method is not limited especially, and all methods can be used. For example, a resonance method, a pulse method, a sing around method and the like are enumerated. In a measuring apparatus, e.g. a pulse signal is converted into a sound-wave signal by a first piezoelectric element, the sound-wave signal which passes through a sample through a first buffer rod is received by a second buffer rod, the sound- wave signal is converted again into a pulse signal by a second piezoelectric element, and the sound velocity of sound waves which pass through the sample is measured. |
