Evaluation of ageing in asphalt cores using low-field nuclear magnetic resonance |
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| Authors: | Ilaria Menapace Eyad Masad Georgios Papavassiliou Emad Kassem |
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| Affiliation: | 1. Texas A&2. M University at Qatar, PO Box 23874, Doha, Qatar;3. Institute of Advanced Materials Physicochemical Properties Nanotechnology and Microsystems NCSR Demokritos, Patriarchou Grigoriou &4. Neapoleos Str., 153 10 Aghia Paraskevi, Attiki, Greece;5. M Transportation Institute, 3135 TAMU, College Station, TX 77843-3135, USA |
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| Abstract: | This paper introduces an innovative methodology for estimating the ageing of asphalt concrete cores without extracting the binder. Asphalt concrete samples at different ageing stages (unaged, 3-month and 6-month aged) and with different percent air voids (4%, 7% and 10%) were analysed with low-field nuclear magnetic resonance (NMR). The transverse relaxation time T2 and relative hydrogen index (RHI) obtained from NMR measurements were related to the viscosity of the asphalt binder. The samples were analysed during cooling from 70°C to room temperature, showing increase in viscosity with decreasing temperature. There was a clear trend indicating higher viscosities in samples that were aged for a longer period and samples with higher percent air voids. The RHI and T2 values obtained from low-field NMR measurements and the viscosity data calculated from measurements using a dynamic shear rheometer were correlated to develop a model that relates viscosity with RHI. |
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| Keywords: | asphalt nuclear magnetic resonance viscosity ageing T2 relative hydrogen index dynamic shear rheometer |
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