Investigation of fracture behaviors of asphalt mixtures with different loading rates based on acoustic emission

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Embargo ends: 2027-06-04

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en

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12

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Theoretical and Applied Fracture Mechanics, Volume 139, part A

Abstract

This study investigated the fracture behaviors of AC10 asphalt mixture under four loading rates (0.2, 0.5, 2, and 5 mm/min) at 25 °C using semi-circular bending (SCB) tests combined with acoustic emission (AE) technology. Mechanical response − including load–displacement curves, fracture energy, elastic energy, and plastic energy − were analyzed, and damage development was evaluated through these energy parameters. AE parameters such as amplitude, count, energy, b-value, and RA-AF characteristics were utilized to characterize crack initiation, propagation, and failure modes. Results demonstrate that fracture energy exhibits a non-linear relationship with increasing loading rate, peaking at 0.5 mm/min, with post-peak fracture energy declining sharply at higher rates, indicative of enhanced brittleness. As the loading rate increased from 0.2 mm/min to 2 mm/min, damage progression accelerated based on the correlation between damage level and normalized displacement. AE amplitude distributions revealed a higher proportion of high-amplitude events (≥55 dB) at faster loading rates, reflecting intensified energy release. Cumulative count and energy curves were classified into three stages: microcrack closure, dynamic crack propagation, and failure stabilization. These trends inversely correlated with b-value dynamics: low b-values signaled macro-crack nucleation or accelerated growth, while high b-values corresponded to microcrack-dominated behavior. Both cumulative counts and energy increased significantly with loading rate. Gaussian mixture modeling (GMM) of RA-AF data identified a transition from shear to tensile cracking at higher loading rates, attributed to reduced viscoelastic deformation and accelerated brittle fracture mechanisms.

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Publisher Copyright: © 2025 Elsevier Ltd

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Song, W, Yan, W, Wu, H, Sun, Y, Chen, X & Cheng, Z 2025, 'Investigation of fracture behaviors of asphalt mixtures with different loading rates based on acoustic emission', Theoretical and Applied Fracture Mechanics, vol. 139, part A, 105034. https://doi.org/10.1016/j.tafmec.2025.105034