Acoustic emission in asphalt mixtures at low temperature

The objective of the research was to investigate the use of acoustic emission to analyze the microstructural phenomena of damage and the corresponding macroscopic behavior in asphalt mixtures tested at low temperature. An acoustic emission system with eight channels of recording was used to monitor the specimens tested in creep and in strength testing. The source location and the AE event count were used to illustrate the relationship between the micro damage and macroscopic behavior for the two different test conditions. The analysis indicates that a damage zone develops in both the creep and the strength tests. The damage zone changes with the test temperature and the loading level applied during the creep test.