SEGJ Technical Conference

Development of a non-contact measurement system of physical properties of pavements (Part 1): Background of the development and production of a prototype

Abstract We newly developed a non-contact surface wave measurement tool using arrayed microphones, and tested it on actual pavements. The tool comprises two microphone arrays, each of which is composed of 24 microphones at 5 cm intervals. The microphone arrays are suspended in a sound insulation box cart, about 2 cm above the pavement surface. Each microphone is also hooded to reduce direct air wave noises. A PC controlled, 48-channel high-speed data acquisition system is used to observe leaky surface waves. Comparative measurements using accelerometers pasted on the pavement surface were conducted to certify whether the tool could discriminate the surface wave phase. As a result, the tool could successfully measure leaky surface waves which showed clear dispersion in the frequency range from 200 to 6,000 Hz. The dispersion curves were essentially same with each other. The field tests demonstrated the tool was quite capable for the continuous pavement assessment.