EVALUATION OF ATTENUATION OF ULTRASONIC WAVE IN AIR TO MEASURE CONCRETE ROUGHNESS USING AERIAL ULTRASONIC SENSOR

Abstract

In Japan, the total length of the main concrete agriculture irrigation canals is estimated to be
about 50,000 km. These canals deteriorate over time and most of the canal surface has become rough. One
method of measurement of the roughness of the concrete surface is by the aerial ultrasonic sensor. As far as
the literature is concerned, no study of the use of 42-kHz sensors for the evaluation of ultrasonic attenuation
during air propagation has been conducted. The aim of this study is to evaluate and correct the attenuated values
of an ultrasonic wave. In this paper, the reflected wave of the ultrasonic wave was measured under different
conditions of temperature, humidity, and atmospheric pressure with a smooth board and a rough board. These
were corrected by using the ISO9613-1 equation. It is concluded that the relative error of the corrected value
is small when compared with the measured value. The results of this study reveal that correction using the
ISO9613-1 equation for attenuation of the 42-kHz ultrasonic wave is an effective method.