An acoustic emission-based test to evaluate low temperature behavior of asphalt materials

Abstract

Low temperature cracking in asphalt pavements located in cold climates is a major cause of pavement deterioration. Accurate evaluation of low temperature cracking behavior of asphalt materials is necessary in order to design pavements that are resistant to thermally induced cracking. Detrimental effects of low-temperature cracking have motivated a number of studies in an effort to experimentally design and control asphalt properties related to the low temperature performance of asphalt pavements. However, accurate predictions of thermal cracking and associated failure mechanisms still remain a challenge. In the present study, an acoustic emission-based testing method was developed to address the current shortage of a rapid and practical test to evaluate the low temperature cracking performance of asphalt binders and mixtures. The developed testing technique has been successfully implemented to assess several types of asphalt binders and mixtures including: Anti-Oxidant modified asphalt binders, SHRP core asphalt binders, asphalt concrete mixtures containing Reclaimed Asphalt Pavement (RAP) material, Warm Mix Asphalt (WMA) mixtures, Bio-Modified Binders (BMB) mixtures, etc. Results show that this technique is very sensitive to aging level of asphalt materials as well as presence of additives such as WMA additives within binder or mixture. The acoustic emission-based testing method appears to be a viable technique for characterization of low temperature behavior of asphalt materials.