Propagation Characteristics of Acoustic Emission Waves in Three Different Asphalt Pavement Materials

Abstract

Due to the differences of physical and mechanical properties of asphalt pavement materials, asphalt pavement (asphalt mixture) presents complex characteristics. To explore the acoustic emission (AE) wave characteristics of asphalt pavement materials, the automatic sensor test (AST) method was used on coarse aggregate, asphalt, and asphalt mixture at different temperatures. The results show that the peak amplitude and frequency of AE waves in coarse aggregate is the largest, followed by asphalt, and asphalt mixture is the smallest. For asphalt mixture, the larger the nominal maximum size of aggregate, the more serious the waveform distortion, the more complex the frequency distribution, and the smaller the amplitude range of AE waves. AE waves in coarse aggregate is not sensitive to temperature, while the peak amplitude of AE waves in asphalt is linearly related to temperature. The peak amplitude and temperature of AE waves in three gradations of asphalt mixtures can be fitted to obtain the corresponding second-order polynomial. AE wave attenuation is mainly reflected in asphalt mixture, while low-temperature sensitivity is mainly reflected in asphalt and asphalt mixture.