scholarly journals RECYCLING TOWARD SUSTAINABLE PAVEMENT DEVELOPMENT:END-OF-LIFE CONSIDERATIONS IN ASPHALT PAVEMENT

2016 ◽  
Vol 78 (7-2) ◽  
Author(s):  
Peyman Babashamsi ◽  
Nur Izzi Md Yusoff ◽  
Halil Ceylan ◽  
Nor Ghani Md Nor

As quality aggregate sources are depleted, there is a growing importance given to incorporating recycled co-products and waste materials (RCWMs) in new and rehabilitated pavements. An ideal goal would be using recycled materials to create long-lived, well-performing pavement and then being able to use those materials again at the end of their life to create new pavement, thereby effectively achieving a zero-waste highway construction stream. This would not only produce distinct cost advantages, but it would also significantly reduce energy consumption and greenhouse gas (GHG) emissions and eliminate the need for landfill disposal. Drawing from ISO standards and practices, this article reviews the recycling methods and definitions associated with the End-of-Life (EOL) phase and present various EOL considerations for asphalt pavements and the associated challenges to quantify EOL contribution in the pavement life cycle.

2003 ◽  
Vol 33 (6) ◽  
pp. 1061-1075 ◽  
Author(s):  
Ann Kristin Petersen ◽  
Birger Solberg

This paper compares two floor constructions used at the new airport outside Oslo, one made of solid oak and one made of natural stone, to (i) make an inventory of energy consumption and greenhouse gas (GHG) emissions over the life cycle of the two constructions, (ii) calculate the differences regarding GHG emissions and cost, and (iii) determine which factors have the strongest influence on the results. Manufacturing the wood floor required 1.6 times more energy and produced one-third of the GHG emissions compared with the natural stone floor. Over the life cycle, net GHG emissions can be avoided only if the wood is used as a biofuel after the replacement or demolition of the floor. The wooden floor must be competitive on price to be a cost-efficient action against global warming. Per cubic metre of wood floor, emissions of up to 1.263 t of CO2 equivalents can be avoided by a substitution between the two floor constructions. The factors that have the most influence on the result are carbon fixation on forest land, waste handling of wood, and discount rate, the latter reflecting the relative importance over time given to a unit of GHG emissions.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1244
Author(s):  
Qi Jiang ◽  
Fusong Wang ◽  
Quantao Liu ◽  
Jun Xie ◽  
Shaopeng Wu

In this paper, the sustainability of induced healing asphalt pavement is demonstrated by comparing the impact of asphalt pavement maintained by induced healing asphalt pavement technology and traditional maintenance methods (such as milling and overlaying). The functional unit selected is a 1-km lane with an analysis period of 20 years. The stages to be considered are material manufacturing, paving, maintenance, milling and demolition. Two case studies were analyzed to assess the impact of different technologies on the energy consumption and environmental performance of each maintenance alternative. By comparing the energy consumption and environmental emissions of the whole life cycle of pavement under the two technical conditions, the results show that the total energy consumption of traditional asphalt pavement is about 2.5 times that of induction-healed asphalt pavement, and the total greenhouse gas (GHG) emissions of the former are twice as much as that of the latter.


2012 ◽  
Vol 524-527 ◽  
pp. 2538-2544 ◽  
Author(s):  
Worayut Saibuatrong ◽  
Thumrongrut Mungcharoen

Energy consumption and Greenhouse Gas (GHG) of major Alternative vehicle fuels (AVFs) in Thailand are estimated and compared with conventional fuels by means of full Life Cycle Assessment (LCA). The tool utilized here is the Well-to-Wheels (WtW) module of own model covering the entire lifecycle including: raw materials cultivation (or feedstock collection); fuel production; transportation and distribution; and application in automobile engines (ICE and hybrid engine), compared with conventional petroleum-based gasoline and diesel pathways. The model is based on Thailand’s national conditions with Tsinghua-CA3EM model. Part of this model structure has been adjusted to Thailand specific situations. Therefore, a majority of the parameters have been modified with local Thailand data. Results showed that the all alternative vehicle fuels can reduce energy consumption and GHG emissions compared to conventional fuels. Hybrid ICE engine to reduce energy consumption and GHG emissions when compared to the ICE engine. Biofuels-ICE engine, especially bioethanol from molasses, had the highest reduce energy consumption and GHG emissions. LPG- Hybrid ICE engine had the highest reduce energy consumption.


Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Florian Stuhlenmiller ◽  
Steffi Weyand ◽  
Jens Jungblut ◽  
Liselotte Schebek ◽  
Debora Clever ◽  
...  

Modern industry benefits from the automation capabilities and flexibility of robots. Consequently, the performance depends on the individual task, robot and trajectory, while application periods of several years lead to a significant impact of the use phase on the resource efficiency. In this work, simulation models predicting a robot’s energy consumption are extended by an estimation of the reliability, enabling the consideration of maintenance to enhance the assessment of the application’s life cycle costs. Furthermore, a life cycle assessment yields the greenhouse gas emissions for the individual application. Potential benefits of the combination of motion simulation and cost analysis are highlighted by the application to an exemplary system. For the selected application, the consumed energy has a distinct impact on greenhouse gas emissions, while acquisition costs govern life cycle costs. Low cycle times result in reduced costs per workpiece, however, for short cycle times and higher payloads, the probability of required spare parts distinctly increases for two critical robotic joints. Hence, the analysis of energy consumption and reliability, in combination with maintenance, life cycle costing and life cycle assessment, can provide additional information to improve the resource efficiency.


2008 ◽  
Vol 57 (11) ◽  
pp. 1683-1692 ◽  
Author(s):  
Andrea Tilche ◽  
Michele Galatola

Anaerobic digestion is a well known process that (while still capable of showing new features) has experienced several waves of technological development. It was “born” as a wastewater treatment system, in the 1970s showed promise as an alternative energy source (in particular from animal waste), in the 1980s and later it became a standard for treating organic-matter-rich industrial wastewater, and more recently returned to the market for its energy recovery potential, making use of different biomasses, including energy crops. With the growing concern around global warming, this paper looks at the potential of anaerobic digestion in terms of reduction of greenhouse gas (GHG) emissions. The potential contribution of anaerobic digestion to GHG reduction has been computed for the 27 EU countries on the basis of their 2005 Kyoto declarations and using life cycle data. The theoretical potential contribution of anaerobic digestion to Kyoto and EU post-Kyoto targets has been calculated. Two different possible biogas applications have been considered: electricity production from manure waste, and upgraded methane production for light goods vehicles (from landfill biogas and municipal and industrial wastewater treatment sludges). The useful heat that can be produced as by-product from biogas conversion into electricity has not been taken into consideration, as its real exploitation depends on local conditions. Moreover the amount of biogas already produced via dedicated anaerobic digestion processes has also not been included in the calculations. Therefore the overall gains achievable would be even higher than those reported here. This exercise shows that biogas may considerably contribute to GHG emission reductions in particular if used as a biofuel. Results also show that its use as a biofuel may allow for true negative GHG emissions, showing a net advantage with respect to other biofuels. Considering also energy crops that will become available in the next few years as a result of Common Agricultural Policy (CAP) reform, this study shows that biogas has the potential of covering almost 50% of the 2020 biofuel target of 10% of all automotive transport fuels, without implying a change in land use. Moreover, considering the achievable GHG reductions, a very large carbon emission trading “value” could support the investment needs. However, those results were obtained through a “qualitative” assessment. In order to produce robust data for decision makers, a quantitative sustainability assessment should be carried out, integrating different methodologies within a life cycle framework. The identification of the most appropriate policy for promoting the best set of options is then discussed.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5664
Author(s):  
Wenjing Wei ◽  
Peter B. Samuelsson ◽  
Anders Tilliander ◽  
Rutger Gyllenram ◽  
Pär G. Jönsson

The primary energy consumption and greenhouse gas emissions from nickel smelting products have been assessed through case studies using a process model based on mass and energy balance. The required primary energy for producing nickel metal, nickel oxide, ferronickel, and nickel pig iron is 174 GJ/t alloy (174 GJ/t contained Ni), 369 GJ/t alloy (485 GJ/t contained Ni), 110 GJ/t alloy (309 GJ/t contained Ni), and 60 GJ/t alloy (598 GJ/t contained Ni), respectively. Furthermore, the associated GHG emissions are 14 tCO2-eq/t alloy (14 tCO2-eq/t contained Ni), 30 t CO2-eq/t alloy (40 t CO2-eq/t contained Ni), 6 t CO2-eq/t alloy (18 t CO2-eq/t contained Ni), and 7 t CO2-eq/t alloy (69 t CO2-eq/t contained Ni). A possible carbon emission reduction can be observed by comparing ore type, ore grade, and electricity source, as well as allocation strategy. The suggested process model overcomes the limitation of a conventional life cycle assessment study which considers the process as a ‘black box’ and allows for an identification of further possibilities to implement sustainable nickel production.


Author(s):  
Kathrina Simonen ◽  

Research and Practice Environmental Life Cycle Assessment (LCA) can be used to evaluate the environmental impacts of a building resulting from manufacturing, construction, operation and maintenance and the end of life demolition and disposal/re-use. Tracking impacts such as greenhouse gas emissions and smog formation, LCA can enable comparison of building proposals testing options of material use, system selection and system performance.


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