The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Imad L Alqadi - One of the best experts on this subject based on the ideXlab platform.
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development of a life cycle assessment tool to quantify the environmental impacts of airport pavement construction
Transportation Research Record, 2017Co-Authors: Rebekah Yang, Imad L AlqadiAbstract:The environmental impacts of airport pavement construction were evaluated in this study through a life-cycle analysis approach. Total primary energy (TPE) consumption and greenhouse gas (GHG) emissions from Material Production and construction of pavement were determined by using life-cycle assessment (LCA), a quantitative methodology described in the ISO 14040 series. A tool was developed to implement a probabilistic LCA through the Monte Carlo method. This tool allowed for consideration of uncertainty from life-cycle inventory data. A case study on the construction of Runway 10R-28L at Chicago O’Hare International Airport focused on mainline and shoulder pavement designs. Environmental impacts from producing Materials for the pavements increased from lower to upper layers, while asphalt layers had relatively higher TPE consumption than the upper portland cement concrete layer—and vice versa for GHGs. Impacts from Material Production overshadowed those from construction, which contributed less than 2% of...
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environmental and economic analyses of recycled asphalt concrete mixtures based on Material Production and potential performance
Resources Conservation and Recycling, 2015Co-Authors: Rebekah Yang, Seunggu Kang, Hasan Ozer, Imad L AlqadiAbstract:Abstract As roadway construction is a Material and energy intensive activity with potential impacts on the environment, the pavement industry has been seeking for more sustainable construction practices in the past decades. The use of recycled Materials such as reclaimed asphalt pavement (RAP) and recycled asphalt shingle (RAS) is widely accepted as among the most commonly used sustainable strategies for asphalt concrete (AC) pavement due to its ability to partially substitute virgin asphalt binder and aggregate in AC mixtures. This study evaluated the environmental and economic benefits and trade-offs of including recycled Materials in pavements using a life-cycle approach. Eleven AC mix designs from Illinois with various asphalt binder replacement (ABR) rates were evaluated in terms of environmental and economic impacts using life-cycle assessment (LCA) and an itemized cost analysis. The LCA was conducted in accordance to International Standard Organization ISO 14044:2006 guidelines. The life-cycle impacts of producing the AC mixtures were calculated in terms of energy, global warming potential, and cost. A general trend of reduction in these three sustainability metrics was observed for mix Production with increasing ABR. However, without proper modification and engineering of mix designs (e.g. addition of a softer grade virgin asphalt binder), AC mixtures with high ABR can experience reduced fatigue life. Thus, the effect of pavement performance on the environmental impacts of using mixtures with various ABR was also considered, assuming that these mixtures are used in a 4-in. (102-mm) overlay over a four-lane-mile (1.6 km) roadway. A breakeven concept was used to find the decreased service life at which the energy savings from using recycled asphaltic Materials in the overlay equal the additional energy consumption incurred from a potential reduced performance in the pavement use phase. The breakeven point was found to be very sensitive to the traffic level of the overlay, with the breakeven service life decreasing rapidly with increased traffic.
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life cycle greenhouse gases and energy consumption for Material and construction phases of pavement with traffic delay
Transportation Research Record, 2014Co-Authors: Seunggu Kang, Rebekah Yang, Hasan Ozer, Imad L AlqadiAbstract:This paper discusses an approach to life-cycle assessment (LCA) for pavement construction applications. The scope of the study included the Material Production and construction phases pertaining to the upper layers of pavement; the aim was to quantify energy consumption and greenhouse gases. Life-cycle inventory data were taken from literature sources and questionnaires, with system boundaries including upstream processes for the Production of major Materials and fuels. The use of regionalized data was necessary to ensure proper application of LCA. Thus, for the Material Production phase, this LCA included preliminary data collected from regional surveys and incorporated a localized life-cycle model for asphalt binder Production. The impact of traffic delay was modeled in the construction phase with the U.S. Environmental Protection Agency's Motor Vehicle Emission Simulator. A case study was performed for a simulated two-lane reconstruction of an existing Interstate in northern Illinois. The energy consum...
Bo Xiao - One of the best experts on this subject based on the ideXlab platform.
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application of bayer red mud for iron recovery and building Material Production from alumosilicate residues
Journal of Hazardous Materials, 2009Co-Authors: Wanchao Liu, Jiakuan Yang, Bo XiaoAbstract:Red mud is a solid waste produced in the process of alumina extraction from bauxite. In this paper, recovery iron from Bayer red mud was studied with direct reduction roasting process followed by magnetic separation, and then building Materials were prepared from alumosilicate residues. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery efficiency of iron were carried out. The optimum reaction parameters were proposed as the following: ratio of carbon powder: red mud at 18:100, ratio of additives: red mud at 6:100, roasting at 1300 degrees C for 110min. With these optimum parameters, total content of iron in concentrated Materials was 88.77%, metallization ratio of 97.69% and recovery ratio of 81.40%. Then brick specimens were prepared with alumosilicate residues and hydrated lime. Mean compressive strength of specimens was 24.10MPa. It was indicated that main mineral phase transformed from nepheline (NaAlSiO4) in alumosilicate residues to gehlenite (Ca2Al2SiO7) in brick specimens through X-ray diffraction (XRD) technology. The feasibility of this transformation under the experimental conditions was proved by thermodynamics calculation analysis. Combined the recovery of iron with the reuse of alumosilicate residues, it can realize zero-discharge of red mud from Bayer process.
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application of bayer red mud for iron recovery and building Material Production from alumosilicate residues
Journal of Hazardous Materials, 2009Co-Authors: Jiakuan Yang, Bo XiaoAbstract:Abstract Red mud is a solid waste produced in the process of alumina extraction from bauxite. In this paper, recovery iron from Bayer red mud was studied with direct reduction roasting process followed by magnetic separation, and then building Materials were prepared from alumosilicate residues. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery efficiency of iron were carried out. The optimum reaction parameters were proposed as the following: ratio of carbon powder: red mud at 18:100, ratio of additives: red mud at 6:100, roasting at 1300 °C for 110 min. With these optimum parameters, total content of iron in concentrated Materials was 88.77%, metallization ratio of 97.69% and recovery ratio of 81.40%. Then brick specimens were prepared with alumosilicate residues and hydrated lime. Mean compressive strength of specimens was 24.10 MPa. It was indicated that main mineral phase transformed from nepheline (NaAlSiO4) in alumosilicate residues to gehlenite (Ca2Al2SiO7) in brick specimens through X-ray diffraction (XRD) technology. The feasibility of this transformation under the experimental conditions was proved by thermodynamics calculation analysis. Combined the recovery of iron with the reuse of alumosilicate residues, it can realize zero-discharge of red mud from Bayer process.
Rebekah Yang - One of the best experts on this subject based on the ideXlab platform.
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development of a life cycle assessment tool to quantify the environmental impacts of airport pavement construction
Transportation Research Record, 2017Co-Authors: Rebekah Yang, Imad L AlqadiAbstract:The environmental impacts of airport pavement construction were evaluated in this study through a life-cycle analysis approach. Total primary energy (TPE) consumption and greenhouse gas (GHG) emissions from Material Production and construction of pavement were determined by using life-cycle assessment (LCA), a quantitative methodology described in the ISO 14040 series. A tool was developed to implement a probabilistic LCA through the Monte Carlo method. This tool allowed for consideration of uncertainty from life-cycle inventory data. A case study on the construction of Runway 10R-28L at Chicago O’Hare International Airport focused on mainline and shoulder pavement designs. Environmental impacts from producing Materials for the pavements increased from lower to upper layers, while asphalt layers had relatively higher TPE consumption than the upper portland cement concrete layer—and vice versa for GHGs. Impacts from Material Production overshadowed those from construction, which contributed less than 2% of...
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environmental and economic analyses of recycled asphalt concrete mixtures based on Material Production and potential performance
Resources Conservation and Recycling, 2015Co-Authors: Rebekah Yang, Seunggu Kang, Hasan Ozer, Imad L AlqadiAbstract:Abstract As roadway construction is a Material and energy intensive activity with potential impacts on the environment, the pavement industry has been seeking for more sustainable construction practices in the past decades. The use of recycled Materials such as reclaimed asphalt pavement (RAP) and recycled asphalt shingle (RAS) is widely accepted as among the most commonly used sustainable strategies for asphalt concrete (AC) pavement due to its ability to partially substitute virgin asphalt binder and aggregate in AC mixtures. This study evaluated the environmental and economic benefits and trade-offs of including recycled Materials in pavements using a life-cycle approach. Eleven AC mix designs from Illinois with various asphalt binder replacement (ABR) rates were evaluated in terms of environmental and economic impacts using life-cycle assessment (LCA) and an itemized cost analysis. The LCA was conducted in accordance to International Standard Organization ISO 14044:2006 guidelines. The life-cycle impacts of producing the AC mixtures were calculated in terms of energy, global warming potential, and cost. A general trend of reduction in these three sustainability metrics was observed for mix Production with increasing ABR. However, without proper modification and engineering of mix designs (e.g. addition of a softer grade virgin asphalt binder), AC mixtures with high ABR can experience reduced fatigue life. Thus, the effect of pavement performance on the environmental impacts of using mixtures with various ABR was also considered, assuming that these mixtures are used in a 4-in. (102-mm) overlay over a four-lane-mile (1.6 km) roadway. A breakeven concept was used to find the decreased service life at which the energy savings from using recycled asphaltic Materials in the overlay equal the additional energy consumption incurred from a potential reduced performance in the pavement use phase. The breakeven point was found to be very sensitive to the traffic level of the overlay, with the breakeven service life decreasing rapidly with increased traffic.
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life cycle greenhouse gases and energy consumption for Material and construction phases of pavement with traffic delay
Transportation Research Record, 2014Co-Authors: Seunggu Kang, Rebekah Yang, Hasan Ozer, Imad L AlqadiAbstract:This paper discusses an approach to life-cycle assessment (LCA) for pavement construction applications. The scope of the study included the Material Production and construction phases pertaining to the upper layers of pavement; the aim was to quantify energy consumption and greenhouse gases. Life-cycle inventory data were taken from literature sources and questionnaires, with system boundaries including upstream processes for the Production of major Materials and fuels. The use of regionalized data was necessary to ensure proper application of LCA. Thus, for the Material Production phase, this LCA included preliminary data collected from regional surveys and incorporated a localized life-cycle model for asphalt binder Production. The impact of traffic delay was modeled in the construction phase with the U.S. Environmental Protection Agency's Motor Vehicle Emission Simulator. A case study was performed for a simulated two-lane reconstruction of an existing Interstate in northern Illinois. The energy consum...
Rana Pant - One of the best experts on this subject based on the ideXlab platform.
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allocation solutions for secondary Material Production and end of life recovery proposals for product policy initiatives
Resources Conservation and Recycling, 2014Co-Authors: Karen Allacker, Fabrice Mathieux, Simone Manfredi, Nathan Pelletier, C De Camillis, Fulvio Ardente, Rana PantAbstract:Abstract This paper aims at analysing how secondary Materials Production and end of life recovery processes are modelled in life cycle-based environmental assessment methods in order to discuss their suitability in product policy-support contexts, with a focus on Sustainable Consumption and Production (SCP) policies. The equations prescribed in three published, widely recognised standards are evaluated. In addition, more recent modelling approaches that have been adopted in the context of two EU product policy initiatives (the Product Environmental Footprint (PEF) and the Resource Efficiency Assessment of Products (REAPro)) are similarly analysed. All of the methods are scrutinised against eight criteria which we deem to be important in product policy-support contexts, including comprehensiveness, accommodation of open-loop and closed-loop product systems, and consideration of recyclability/recoverability rates, to name a few. Based on this analysis, it is suggested that the PEF and REAPro modelling approaches appear to be better suited for use in product policy-support contexts than do the currently widely endorsed methods that we considered.
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Allocation solutions for secondary Material Production and end of life recovery: Proposals for product policy initiatives
Resources Conservation and Recycling, 2014Co-Authors: Karen Allacker, Fabrice Mathieux, Simone Manfredi, Nathan Pelletier, C De Camillis, Fulvio Ardente, Rana PantAbstract:Abstract This paper aims at analysing how secondary Materials Production and end of life recovery processes are modelled in life cycle-based environmental assessment methods in order to discuss their suitability in product policy-support contexts, with a focus on Sustainable Consumption and Production (SCP) policies. The equations prescribed in three published, widely recognised standards are evaluated. In addition, more recent modelling approaches that have been adopted in the context of two EU product policy initiatives (the Product Environmental Footprint (PEF) and the Resource Efficiency Assessment of Products (REAPro)) are similarly analysed. All of the methods are scrutinised against eight criteria which we deem to be important in product policy-support contexts, including comprehensiveness, accommodation of open-loop and closed-loop product systems, and consideration of recyclability/recoverability rates, to name a few. Based on this analysis, it is suggested that the PEF and REAPro modelling approaches appear to be better suited for use in product policy-support contexts than do the currently widely endorsed methods that we considered.
Robert De Kleine - One of the best experts on this subject based on the ideXlab platform.
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impact of updated Material Production data in the greet life cycle model
Journal of Industrial Ecology, 2014Co-Authors: Robert De Kleine, Gregory A Keoleian, Shelie A Miller, Andrew Burnham, John L SullivanAbstract:type="main"> The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model developed by Argonne National Laboratory quantifies the life cycle energy consumption and air emissions resulting from the Production and use of light-duty vehicles in the United States. GREET is comprised of two components: GREET 1 represents the fuel cycle of various energy carriers, including automotive fuels, and GREET 2 represents the vehicle cycle, which accounts for the Production of vehicles and their constituent Materials. The GREET model was updated in 2012 and now includes higher-resolution Material processing and transformation data. This study evaluated how model updates influence Material and vehicle life cycle results. First, new primary energy demand and greenhouse gas (GHG) emissions results from GREET 2 for steel, aluminum, and plastics resins are compared herein with those from the previous version of the model as well as industrial results. A part of the comparison is a discussion about causes of differences between results. Included in this discussion is an assessment of the impact of the new Material Production data on vehicle life cycle results for conventional internal combustion engine (ICE) vehicles by comparing the energy and GHG emission values in the updated and previous versions of GREET 2. Finally, results from a sensitivity analysis are presented for identifying life cycle parameters that most affect vehicle life cycle estimates.
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impact of updated Material Production data in the greet life cycle model
Journal of Industrial Ecology, 2014Co-Authors: Robert De Kleine, Gregory A Keoleian, Shelie A Miller, Andrew Burnham, John SullivanAbstract:The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model developed by Argonne National Laboratory quantifies the life cycle energy consumption and air emissions resulting from the Production and use of light-duty vehicles in the United States. GREET is comprised of two components: GREET 1 represents the fuel cycle of various energy carriers, including automotive fuels, and GREET 2 represents the vehicle cycle, which accounts for the Production of vehicles and their constituent Materials. The GREET model was updated in 2012 and now includes higher-resolution Material processing and transformation data. This study evaluated how model updates influence Material and vehicle life cycle results. First, new primary energy demand and greenhouse gas (GHG) emissions results from GREET 2 for steel, aluminum, and plastics resins are compared herein with those from the previous version of the model as well as industrial results. A part of the comparison is a discussion about causes of differences between results. Included in this discussion is an assessment of the impact of the new Material Production data on vehicle life cycle results for conventional internal combustion engine (ICE) vehicles by comparing the energy and GHG emission values in the updated and previous versions of GREET 2. Finally, results from a sensitivity analysis are presented for identifying life cycle parameters that most affect vehicle life cycle estimates.
