The aging of asphalt pavements leads to less flexible asphalt mixtures that are prone to cracking and spalling. In this study, the relationship between lab and field aging was evaluated based on both theoretical asphalt aging models and practical asphalt and asphalt mixture performance tests. The results show that the corresponding field aging duration calculated using the mixture testing, especially the cracking test, is more conservative than the traditional aging models or binder rheological measurements. 5 and 12 days appear to simulate 16 and 38 years of field aging (in New Hampshire) for the top 12.5 mm pavement, respectively, based on the asphalt binder test results. In contrast, the theoretical aging model considers climatic conditions and suggests that 5 and 12 days simulate in-field aging of 6.2 and 15.0 years, respectively. The asphalt mixture test results indicate that the laboratory aging conditions simulate minimal field aging durations. This is because the damage to the asphalt pavement structure caused by climatic conditions and traffic loads is fully considered. This could be very useful for designing a more reliable and durable pavement incorporating intricate field conditions.

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Hyperloop is an emerging transportation system that minimises the air resistance by having the vehicle travel inside a de-pressurised tube and eliminates the wheel-rail contact friction by using an electro-magnetic suspension system. Due to the very large target velocities, one of its challenges will be ensuring the system stability. This study aims to determine the velocity regimes in which the system is unstable and, more specifically, is focusing on the interplay between two fundamentally different instability sources, namely (i) the electro-magnetic suspension and (ii) wave-induced instability. To this end, unlike previous studies, the frequency and velocity dependent reaction force provided by the infinite guideway is properly accounted for. Results show that the interplay between the two instability mechanisms does not lead to significant qualitative changes compared to considering each one separately. This study can help Hyperloop engineers avoid excessive vibrations that can cause fatigue problems and, in extreme cases, derailment.@en