Assessment of Anisotropy in Cold In-Place Recycled Materials Using Shear Wave Velocity and Computed Tomography Analysis

Pavement materials like hot mix asphalt (HMA) and cold recycled mixes (CRMs) are typically considered isotropic. This study evaluates the anisotropy of a cold in-place recycled (CIR) material using the shear wave velocity (V<sub>s</sub>) parameter. The piezoelectric ring actuator techniq...

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Bibliographic Details
Main Authors: Quentin Lecuru, Yannic Ethier, Alan Carter, Mourad Karray
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Infrastructures
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Online Access:https://www.mdpi.com/2412-3811/10/5/115
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Summary:Pavement materials like hot mix asphalt (HMA) and cold recycled mixes (CRMs) are typically considered isotropic. This study evaluates the anisotropy of a cold in-place recycled (CIR) material using the shear wave velocity (V<sub>s</sub>) parameter. The piezoelectric ring actuator technique (P-RAT) is utilized to assess the V<sub>s</sub> parameter in three directions in CIR slabs. Similarly, the ultrasonic pulse velocity (UPV) technique is employed to measure P-wave velocities. Both methods evaluate mechanical properties in multiple directions. Complex modulus tests are conducted to link velocities results to |E*| modulus. Finally, computed tomography (CT) scans are performed on the specimens in order to evaluate anisotropy resulting from aggregate alignment. The V<sub>s</sub> obtained using P-RAT and the V<sub>p</sub> from UPV indicate anisotropy, as the wave velocities differ across the three directions. Differences range from 0.6 to 11.6% in V<sub>s</sub>, influenced by measurement location. UPV results are analysed in relation to the |E*| modulus master curves, demonstrating that the first peak arrival time for the P-wave corresponds with the master curve. CT scan analysis reveals that the aggregates tend to be more aligned in the direction of the compacting wheel’s displacement, which also highlights anisotropy.
ISSN:2412-3811