scholarly journals Life Cycle Assessment of alkali activated materials: preliminary investigation for pavement applications

2021 ◽  
Vol 6 ◽  
pp. 124-130
Author(s):  
Francesca Lolli ◽  
Kimberly E. Kurtis
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Capital Investment ◽  
Mechanical Performance ◽  
Preliminary Investigation ◽  
Raw Material ◽  
Cement Concrete ◽  
Usual Practice ◽  
The Impact ◽  
Alkali Activated

The capital investment in the US for construction and maintenance of the infrastructure road network is $150 billion/year. Investments in OECD countries will likely stabilize, while other countries will face an exponential growth of investments for infrastructures driven by the development of metropolitan cities. Continued “business-as-usual” practice for portland and asphalt cement concrete pavement construction ignores the increasing warning calls for the identification of more sustainable and less energy intensive paving materials. Alkali activated materials concrete (AAM) have been studied with growing interest during the last three decades. AAM show promising results in terms of mechanical performance, while also having a global warming potential impact 30-80% less than that of portland cement concrete. The global warming potential of AAM is closely dependent on the: 1) activating solution used to activate the raw material and 2) origin of the raw material. Specifically, the impact of the transport for both of these components is ~ 10% of its global warming potential. Hence, to increase the adoption of AAM for pavements, it is fundamental to analyze the existing literature to clarify the link between environmental impact and mechanical performance, identifying opportunities for applications that are tailored to the local availability of raw material.

Analysis on the Global Warming Potential of Cement Concrete Pavement in China

2015 ◽  
Vol 814 ◽  
pp. 418-424
Author(s):  
Li Li Zhao ◽  
Zhi Hong Wang ◽  
Yu Liu ◽  
Xian Zheng Gong ◽  
Feng Gao ◽  
...  
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Road Construction ◽  
Concrete Pavement ◽  
Raw Material ◽  
Cement Concrete ◽  
Environment Impact ◽  
Cement Concrete Pavement ◽  
Materials Used ◽  
Total Impact

The global warming of cement concrete pavement from raw material extraction to road construction was analyzed by the method of life cycle assessment. The characterization results showed that the procedure of producing material is the most important stage to emit greenhouse gas and it accounts for 98.5% of the global warming potential that caused by the material production and construction stage. For the materials used in different structure layers, surface layer is the biggest impact of greenhouse and accounts for 68.9% of the total impact caused by material used in constructing pavement. Therefore in the future, by using recycled materials or more environmental materials will be a good way to reduce environment impact.

scholarly journals Predicting the global warming potential of agro-ecosystems

2007 ◽  
Vol 4 (2) ◽  
pp. 1059-1092 ◽  
Author(s):  
S. Lehuger ◽  
B. Gabrielle ◽  
E. Larmanou ◽  
P. Laville ◽  
P. Cellier ◽  
...  
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Cropping Systems ◽  
C Sequestration ◽  
N2o Emissions ◽  
Data Sets ◽  
Management Scenarios ◽  
Global Warming Impact ◽  
Sequestration Potential ◽  
The Impact

Abstract. Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHG) contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to environmental conditions and crop management. Here, we used two year-round data sets from two intensively-monitored cropping systems in northern France to test the ability of the biophysical crop model CERES-EGC to simulate GHG exchanges at the plot-scale. The experiments involved maize and rapeseed crops on a loam and rendzina soils, respectively. The model was subsequently extrapolated to predict CO2 and N2O fluxes over an entire crop rotation. Indirect emissions (IE) arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. One experimental site (involving a wheat-maize-barley rotation on a loamy soil) was a net source of GHG with a GWP of 350 kg CO2-C eq ha−1 yr−1, of which 75% were due to IE and 25% to direct N2O emissions. The other site (involving an oilseed rape-wheat-barley rotation on a rendzina) was a net sink of GHG for –250 kg CO2-C eq ha−1 yr−1, mainly due to a higher predicted C sequestration potential and C return from crops. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming impact.

scholarly journals Environmental Payback of Renovation Strategies in a Northern Climate—the Impact of Nuclear Power and Fossil Fuels in the Electricity Supply

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 80 ◽  
Author(s):  
Ricardo Ramírez-Villegas ◽  
Ola Eriksson ◽  
Thomas Olofsson
Keyword(s):  
European Union ◽  
Energy Efficiency ◽  
Global Warming ◽  
Life Cycle ◽  
Radioactive Waste ◽  
Global Warming Potential ◽  
Nuclear Power ◽  
Fossil Fuels ◽  
The European Union ◽  
The Impact

The aim of this study is to assess how the use of fossil and nuclear power in different renovation scenarios affects the environmental impacts of a multi-family dwelling in Sweden, and how changes in the electricity production with different energy carriers affect the environmental impact. In line with the Paris Agreement, the European Union has set an agenda to reduce greenhouse gas emissions by means of energy efficiency in buildings. It is estimated that by the year 2050, 80% of Europe’s population will be living in buildings that already exist. This means it is important for the European Union to renovate buildings to improve energy efficiency. In this study, eight renovation scenarios, using six different Northern European electricity mixes, were analyzed using the standard of the European Committee for Standardization for life cycle assessment of buildings. This study covers all life cycle steps from cradle to grave. The renovation scenarios include combinations of photovoltaics, geothermal heat pumps, heat recovery ventilation, and improvement of the building envelope. The results show that while in some electricity mixes a reduction in the global warming potential can be achieved, it can be at the expense of an increase in radioactive waste production, and, in mixes with a high share of fossil fuels, the global warming potential of the scenarios increases with time, compared with that of the original building. It also shows that in most electricity mixes, scenarios that reduce the active heat demand of the building end up in reducing both the global warming potential and radioactive waste, making them less sensitive to changes in the energy system.

Effect of unrefined crude glycerol composition on the properties of polyurethane foams

2017 ◽  
Vol 54 (3) ◽  
pp. 633-649 ◽  
Author(s):  
Nuno V Gama ◽  
Belinda Soares ◽  
Carmen SR Freire ◽  
Rui Silva ◽  
Artur Ferreira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Crude Glycerol ◽  
Mechanical Performance ◽  
Methyl Esters ◽  
Thermomechanical Properties ◽  
Polyurethane Foams ◽  
Raw Material ◽  
Two Samples ◽  
Pre Treatment ◽  
The Impact

The aim of this study is to evaluate the possibility of using unrefined crude glycerol (CG), a byproduct of the biodiesel industry, in the production of polyurethane foams. In order to assess the suitability of this raw material for the production of polyurethane foams, two samples of crude glycerol with different compositions in glycerol, fatty acids, and methyl esters were used directly, without any pretreatment or purification. Additionally, one of these samples was also submitted to a pre-treatment step in order to evaluate the advantage of purifying the raw material and, for comparison, pure glycerol was also used to prepare polyurethane foams. Both chemical and structural characterizations of the produced foams, as well as the thermomechanical properties determined, showed that unrefined crude glycerol is a suitable ecopolyol for the production of polyurethane foams. Although the presence of fatty acids and esters affects their mechanical performance, this issue can be explored to tune the properties of the ensuing polyurethane foams. Furthermore, the evaluation of the impact of using unrefined CG on the sustainability of polyurethane foams production yielded promising results.

Quasi-Static Impact Response of Single-Curved Foldcore Sandwich Shells

2014 ◽  
Author(s):  
Joseph M. Gattas ◽  
Zhong You
Keyword(s):  
Energy Absorption ◽  
Mechanical Performance ◽  
Numerical Models ◽  
Preliminary Investigation ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Future Research ◽  
Initial Strength ◽  
Sandwich Shells ◽  
The Impact

Honeycomb core sandwich shells are used for many applications, but available unit architectures and global curvatures are limited. Numerous origami-core sandwich shells, known as foldcores, have been proposed as alternatives, but studies into their mechanical performance are few. This paper conducts a preliminary investigation into the impact resistance and energy absorption of single-curved foldcore sandwich shells that utilise Miura-derivative patterns as their core geometry. A numerical analysis on three Miura-derivative core patterns, the Arc-Miura (AM), Non-Developable Miura (ND), and Non-Flat Foldable Miura (NF) patterns, shows that ND and AM-type shells have similar impact resistance to each other, and superior impact resistance to NF-type shells. Prototypes of aluminium ND and AM-type foldcores are constructed and used to validate numerical models. Numerical models were then used to draw comparisons with an over-expanded honeycomb (OX-core) sandwich shell. It was seen that the OX-core had a better energy absorption capacity than either of the foldcores. However the AM-type foldcore possessed superior initial strength, and the ND-type possessed superior response uniformity, attributes that might be exploitable with future research. A brief parametric study on ND-type shells suggested that in general, for a given design radius and density, a foldcore shell configuration with a lower unit cell area-to-height ratio will have a higher energy absorption capability.

scholarly journals The impact on global warming potential of converting from disposable to reusable sharps containers in a large US hospital geographically distant from polymer and container manufacturer

2018 ◽  
Author(s):  
Brett McPherson ◽  
Mihray Sharip ◽  
Terry Grimmond
Keyword(s):  
Global Warming ◽  
Health System ◽  
Global Warming Potential ◽  
Ghg Emissions ◽  
Medical Waste ◽  
University Hospital ◽  
Waste Stream ◽  
Unit Process ◽  
Ghg Reduction ◽  
The Impact

Background. Sustainable purchasing can reduce greenhouse gas (GHG) emissions at healthcare facilities (HCF). A previous study found that converting from disposable to reusable sharps containers (DSC, RSC) reduced sharps waste stream GHG by 84% but, in finding transport distances impacted significantly on GHG outcomes, recommended further studies where transport distances are large. This case-study examines the impact on GHG of nation-wide transport distances when a large US health system converted from DSC to RSC. Methods. The study examined the alternate use of DSC and RSC at a large US university hospital where: the source of polymer was distant from the RSC manufacturing plant; both manufacturing plants were over 3,000 km from the HCF; and the RSC disposal plant was considerably further from the HCF than was the DSC disposal plant. Using a “cradle to grave” life cycle assessment (LCA) tool we calculated annual GHG emissions (CO2, CH4, N2O) in metric tonnes of carbon dioxide equivalents (MTCO2eq) to assess the impact on global warming potential (GWP) of each container system. Primary energy input data was used wherever possible and region-specific impact conversions used to calculate GWP of each activity over a 12-month period. Unit process GHG were collated into Manufacture, Transport, Washing, and Treatment & disposal. Emission totals were workload-normalized and analysed using CHI2 test with P ≤0.05 and rate ratios at 95% CL. Results. The hospital reduced its annual GWP by 168 MTCO2eq (-64.5%; p < 0.001), and annually eliminated 50.2 tonnes of plastic DSC and 8.1 tonnes of cardboard from the sharps waste stream. Of the plastic eliminated, 31.8 tonnes were diverted from landfill and 18.4 from incineration. Discussion. Unlike GHG reduction strategies dependent on changes in staff behaviour (waste segregation, recycling, turning off lights, car-pooling, etc), purchasing strategies can enable immediate, sustainable and institution-wide GHG reductions to be achieved. Medical waste containers contribute significantly to the supply chain carbon footprint and, although non-sharp medical waste volumes have decreased significantly with avid segregation, sharps wastes have increased, and can account for 50% of total medical waste volume. Thus converting from DSC to RSC can assist reduce the GWP footprint of the medical waste stream. This study confirmed that large transport distances between polymer manufacturer and container manufacturer; container manufacturer and user; and/or between user and processing facilities, can significantly impact the GWP of sharps containment systems. However, even with large transport distances, we found that a large university health system significantly reduced the GWP of their sharps waste stream by converting from DSC to RSC.

scholarly journals The impact on global warming potential of converting from disposable to reusable sharps containers in a large US hospital geographically distant from polymer and container manufacturer

2018 ◽  
Author(s):  
Brett McPherson ◽  
Mihray Sharip ◽  
Terry Grimmond
Keyword(s):  
Global Warming ◽  
Health System ◽  
Global Warming Potential ◽  
Ghg Emissions ◽  
Medical Waste ◽  
University Hospital ◽  
Waste Stream ◽  
Unit Process ◽  
Ghg Reduction ◽  
The Impact

Background. Sustainable purchasing can reduce greenhouse gas (GHG) emissions at healthcare facilities (HCF). A previous study found that converting from disposable to reusable sharps containers (DSC, RSC) reduced sharps waste stream GHG by 84% but, in finding transport distances impacted significantly on GHG outcomes, recommended further studies where transport distances are large. This case-study examines the impact on GHG of nation-wide transport distances when a large US health system converted from DSC to RSC. Methods. The study examined the alternate use of DSC and RSC at a large US university hospital where: the source of polymer was distant from the RSC manufacturing plant; both manufacturing plants were over 3,000 km from the HCF; and the RSC disposal plant was considerably further from the HCF than was the DSC disposal plant. Using a “cradle to grave” life cycle assessment (LCA) tool we calculated annual GHG emissions (CO2, CH4, N2O) in metric tonnes of carbon dioxide equivalents (MTCO2eq) to assess the impact on global warming potential (GWP) of each container system. Primary energy input data was used wherever possible and region-specific impact conversions used to calculate GWP of each activity over a 12-month period. Unit process GHG were collated into Manufacture, Transport, Washing, and Treatment & disposal. Emission totals were workload-normalized and analysed using CHI2 test with P ≤0.05 and rate ratios at 95% CL. Results. The hospital reduced its annual GWP by 168 MTCO2eq (-64.5%; p < 0.001), and annually eliminated 50.2 tonnes of plastic DSC and 8.1 tonnes of cardboard from the sharps waste stream. Of the plastic eliminated, 31.8 tonnes were diverted from landfill and 18.4 from incineration. Discussion. Unlike GHG reduction strategies dependent on changes in staff behaviour (waste segregation, recycling, turning off lights, car-pooling, etc), purchasing strategies can enable immediate, sustainable and institution-wide GHG reductions to be achieved. Medical waste containers contribute significantly to the supply chain carbon footprint and, although non-sharp medical waste volumes have decreased significantly with avid segregation, sharps wastes have increased, and can account for 50% of total medical waste volume. Thus converting from DSC to RSC can assist reduce the GWP footprint of the medical waste stream. This study confirmed that large transport distances between polymer manufacturer and container manufacturer; container manufacturer and user; and/or between user and processing facilities, can significantly impact the GWP of sharps containment systems. However, even with large transport distances, we found that a large university health system significantly reduced the GWP of their sharps waste stream by converting from DSC to RSC.

Correlation of Global Warming Potential and Atmospheric Life Times of Halocarbons

2009 ◽  
Author(s):  
Suman Kumar Sharma
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Large Scale ◽  
Life Form ◽  
Warming Trend ◽  
Economic Consequences ◽  
Empirical Relations ◽  
Food Shortages ◽  
Important Challenge ◽  
The Impact

Sustainability of life form on the earth is a major concern of every nation, which stems from the continued global warming trend, which has become a major policy, political, and economic issue. Global warming is the most important challenge thrown by the human activities largely due to rapid pace of industrialization in the twenty first century. The impact is likely to extend to next few centuries and unless controlled there would be irrevocable damage to the life form on this planet. Human made halocarbons have a high global warming potential, and some still have the potential to cause damage to the ozone layer as well if released to the atmosphere. The implications of global warming have far-reaching effects beyond the imagination of common person. Rise in global temperature, rise in sea level, food shortages, large scale spread of diseases & infections, catastrophic economic consequences and colossal loss of bio-diversity are some of the major implications of global warming trend. Although many methods are in vogue for comparison of impact of global warming of different compounds, yet the concept of Global warming potential with reference to Carbon dioxide is the simplest one and is widely used. An endeavor has been made in this paper to correlate and develop empirical relations of global warming potential and atmospheric lifetimes of Halocarbons. A new parameter Glife has been evolved for this purpose.

scholarly journals MICRO-MECHANICAL PERFORMANCE OF CONCRETE USED AS RECYCLED RAW MATERIAL IN CEMENTITIOUS COMPOSITE

2017 ◽  
Vol 13 ◽  
pp. 55 ◽  
Author(s):  
Vladimír Hrbek ◽  
Veronika Koudelková ◽  
Zdeněk Prošek ◽  
Pavel Tesárek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Industrial Pollution ◽  
Mechanical Performance ◽  
Structural Parameters ◽  
Raw Material ◽  
Cementitious Composite ◽  
X Ray ◽  
The Impact ◽  
Scanning Electron

The reduction of industrial pollution is recently one of main goals over all fields. In civil engineering, re-cycling of structural waste provides wide opportunity contributing this effort. This paper focus on re-use of concrete waste, which after further processing can be used in new constructions as partial supplement to the mixture. To investigate the impact of re-cycled concrete addition, it is necessary to determine mechanical and structural parameters of individual phases in the “raw” material. For this purpose, grid indentation and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM, EDX) are combined to determine properties of concrete sample.

scholarly journals Global Warming Potential of Biomass-to-Ethanol: Review and Sensitivity Analysis through a Case Study

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2535 ◽  
Author(s):  
Rui Pacheco ◽  
Carla Silva
Keyword(s):  
Global Warming ◽  
Environmental Sustainability ◽  
Global Warming Potential ◽  
Intergovernmental Panel ◽  
Methodological Choices ◽  
The Usa ◽  
Electricity Mix ◽  
Ch4 And N2o ◽  
The Impact ◽  
Biomass To Ethanol

In Europe, ethanol is blended with gasoline fuel in 5 or 10% volume (E5 or E10). In USA the blend is 15% in volume (E15) and there are also pumps that provide E85. In Brazil, the conventional gasoline is E27 and there are pumps that offer E100, due to the growing market of flex fuel vehicles. Bioethanol production is usually by means of biological conversion of several biomass feedstocks (first generation sugar cane in Brazil, corn in the USA, sugar beet in Europe, or second-generation bagasse of sugarcane or lignocellulosic materials from crop wastes). The environmental sustainability of the bioethanol is usually measured by the global warming potential metric (GWP in CO2eq), 100 years time horizon. Reviewed values could range from 0.31 to 5.55 gCO2eq/LETOH. A biomass-to-ethanol industrial scenario was used to evaluate the impact of methodological choices on CO2eq: conventional versus dynamic Life Cycle Assessment; different impact assessment methods (TRACI, IPCC, ILCD, IMPACT, EDIP, and CML); electricity mix of the geographical region/country for different factory locations; differences in CO2eq factor for CH4 and N2O due to updates in Intergovernmental Panel on Climate Change (IPCC) reports (5 reports so far), different factory operational lifetimes and future improved productivities. Results showed that the electricity mix (factory location) and land use are the factors that have the greatest effect (up to 800% deviation). The use of the CO2 equivalency factors stated in different IPCC reports has the least influence (less than 3%). The consideration of the biogenic emissions (uptake at agricultural stage and release at the fermentation stage) and different allocation methods is also influential, and each can make values vary by 250%.

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