Reinforcement evaluation of different fibers on fracture resistance of asphalt mixture based on acoustic emission technique.

• AE could effectively classify the damage stages of asphalt mixture. • The main fracture of asphalt mixture was postponed after the fibers added. • Steel fiber showed superior cracking resistance of asphalt mixture. Fibers have been proven to enhance the stability and mechanical strength of asphalt mixture, but different fibers exhibited diverse characteristics of reinforcement effect. This study is set out to investigate the fiber reinforcement effect of asphalt mixture containing glass fiber reinforced asphalt mixture (GFRAM), basalt fiber reinforced asphalt mixture (BFRAM), and steel fiber reinforced asphalt mixture (SFRAM). The control asphalt mixture (CAM) was also fabricated for comparison. The fiber content was 0.5% by weight of the asphalt mixture and the specimens were manufactured following the Marshall compaction method. Indirect tensile test (IDT) and acoustic emission (AE) test at low temperature were conducted simultaneously to characterize the fracture resistance of different types of fiber reinforced asphalt mixture (FRAM). The amplitude, count, rise angle (RA), average frequency (AF), and b-value were obtained based on AE signal analysis to evaluate FRAM's reinforcement effect. The results revealed that the addition of fibers dramatically improved the strength of CAM, and the occurrence of the main fracture in FRAM emerged later than CAM. SFRAM exhibited more favorable anti-cracking performance than GFRAM and BFRAM based on the comprehensive AE signals analysis. [ABSTRACT FROM AUTHOR]