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- Akbarian, Mehdi, et al.
(författare)
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LCA+: Moving LCA into the Pavement Design Space
- 2012
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Ingår i: Proceeding of ACI International Convention.
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Konferensbidrag (refereegranskat)abstract
- The construction, operation, and maintenance of the United States roadway system are responsible for substantial energy and resource consumption. The current system of paved roads in the United States handles a volume of traffic on the order of 8 billion vehicle-miles per day. Due to high energy demand, road transport contributed the most greenhouse gases (GHGs) of any transportation mode in 2007, accounting for 83% of emissions from the transportation sector and 27% of all emissions in the United States. Improving the sustainability of this network requires better technical and decision making strategies starting with the design stage of pavements.While the Mechanistic-Empirical Pavement Design Guide (MEPDG) is being adopted as a design tool throughout the U.S. it lacks the ability to take into account the environmental impacts of pavement systems. Hence, it is necessary to incorporate the performance designs of MEPDG with an environmental assessment tool to merge the structural and environmental aspects of pavement design.The environmental impact of pavements throughout their lifetime is calculated using the life cycle assessment (LCA) technique. Conventional environmental assessments of pavements often overlook use phase related emissions, leading to conclusions based on incomplete results. Studies have empirically shown that an important factor in the life cycle assessment of pavements is the pavement-vehicle interaction (PVI) which describes the effect of pavement properties on vehicle fuel consumption. However, the results of these studies are not conclusive and cannot be generalized to all pavement designs.This research uses a mechanistic approach to rationalize PVI and creates a link between pavement properties and their impacts on fuel consumption. Moreover, a network-level analysis has been performed using the Long Term Pavement Performance (LTPP) program’s databases to calibrate and validate this model. Finally, life cycle assessment is taken into the design space by incorporating MEPDG designs with LCA principles, taking into account the effect of PVI over the pavement’s lifetime. Moreover, evaluation of high performance sustainable pavement systems is enabled by extending the realm of MEPDG to model-based LCA principles. Through this approach, pavement design is enhanced structurally and environmentally constructing the necessary foundations for LCA+.
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| 2. |
- Engholm, Albin, 1991-, et al.
(författare)
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Exploring cost performance tradeoffs and uncertainties for electric- and autonomous electric trucks using computational experiments
- 2024
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Ingår i: European Transport Research Review. - : Springer Nature. - 1867-0717 .- 1866-8887. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- The recent development of battery electric trucks (BETs) suggests that they could play a vital role in transitioning to zero-emission road freight. To facilitate this transition, it is important to understand under which conditions BETs can be a viable alternative to internal combustion engine trucks (ICETs). Concurrently, the advancement of autonomous driving technology adds uncertainty and complexity to analyzing how the cost competitiveness of future zero-emissions trucks, such as autonomous electric trucks (AETs) may develop. This study examines the cost performance of BETs and AETs compared to ICETs, and how it varies over different market and technology conditions, charging strategies, and transport applications. Focus is on heavy-duty tractor-trailer trucks operating full truckload shuttle-flows in Sweden. Due to the inherent uncertainty and interactions among the analyzed factors, the analysis is performed as computational experiments using a simulation model of BET, AET, and ICET shuttle flow operations and associated costs. In total, 19,200 experiments are performed by sampling the model across 1200 scenarios representing various transport applications and technical and economic conditions for sixteen charging strategies with different combinations of depot, destination, and en route charging. The results indicate that both BETs and AETs are cost competitive compared to ICETs in a large share of scenarios. High asset utilization is important for offsetting additional investment costs in vehicles and chargers, highlighting the importance of deploying these vehicles in applications that enable high productivity. The cost performance for BETs is primarily influenced by energy related costs, charging strategy, and charging infrastructure utilization. The AET cost performance is in addition heavily affected by remote operations cost, and costs for the automated driving system. When feasible, relying only on depot charging is in many scenarios the most cost-effective charging strategy, with the primary exceptions being highly energy-demanding scenarios with long distances and heavy goods in which the required battery is too heavy to operate the truck within vehicle weight regulations if not complemented by destination, or en route charging. However, many experiments do not lead to a reduced payload capacity for BETs and AETs compared to ICETs, and a large majority of the considered scenarios are feasible to operate with a BET or AET within current gross vehicle weight regulations.
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