Klimatförändringar till följd av ökade utsläpp av växthusgaser är en av dom största utmaningarna som dagens samhälle står inför. Byggsektorn står för en betydande del av alla utsläpp och dessa behöver minska för att skapa ett hållbart samhälle. Syftet med studien är att undersöka om stagning av pelare leder till minskad klimatpåverkan och om effekten skiljer sig mellan olika konstruktionsmaterial. Studien använder en hallbyggnad med VKR-pelare som referensobjekt. Byggnaden dimensioneras även med limträpelare och HEA-pelare med likvärdig utnyttjandegrad för jämförelse av konstruktionsmaterialen. Pelarna dimensioneras för två fall där dom antingen är stagade eller ostagade. Klimatpåverkan beräknas under hela byggnadens livscykel med indikatorn GWP. Resultatet visar att effekten av stagning skiljer sig åt mellan dom olika konstruktionsmaterialen. Stagning av limträpelare leder inte till någon minskad klimatpåverkan, medan stagning av stålpelare minskar påverkan för båda profilerna. VKR-pelarens klimatpåverkan minskar med 4,6 procent och HEA-pelarens med 14,2 procent. Även om stålpelarna stagas är det limträpelaren som har klart lägst klimatpåverkan, och är därmed det konstruktionsmaterial som är att föredra ur ett hållbarhetsperspektiv. HEA-pelaren som är den av stålpelarna med lägst klimatpåverkan har mer än sju gånger så hög klimatpåverkan som pelaren i limträ. VKR-pelaren har i sin tur mer än dubbelt så hög klimatpåverkan som HEA-pelaren vilket belyser att även valet av stålprofil har betydelse. / Climate changes as a result of increased greenhouse gas emissions is one of the biggest challenges facing todays’s society. The construction sector accounts for a significant part of all emissions and these need to be reduced in order to create a sustainable society. The purpose of the study is to investigate whether bracing of columns leads to reduced climate impact and whether the effect differs between different construction materials. The study uses a hall building with VKR-columns as a reference object. The building is also dimensioned with glulam columns and HEA-columns with an equivalent degree of utilization for comparison of the construction materials. The columns are dimensioned for two cases where they are either braced or not. Climate impact is calculated with the indicator GWP during the building's entire life cycle. The results show that the effect of bracing differs between the different construction materials. Bracing of glulam columns does not lead to any reduced climate impact, while bracing of steel columns reduces the impact on both profiles. The climate impact of the VKR-column decreases by 4.6 percent and the HEA-column decreases by 14.2 percent. Even if the steel columns are braced, it is the glulam column that has by far the lowest climate impact and thus it is the construction material that is preferable from a sustainability perspective. The HEA column, which is the steel column with the lowest climate impact, has a climate impact which is more than seven times as high as the glulam column. The VKR columns climate impact is twice as high as the HEA column, which highlights that the choice of steel profile is also important. / <p>2022-06-22</p>

Wool is often being marketed as sustainable. However, when looking at LCA studies, results can be significantly different from one study to another and wool sometimes shows higher impacts than other fabrics. Based on a comprehensive literature review, this thesis aims at understanding the key environmental impacts of wool production and assessing the influence of main methodological choices on wool LCA results. In particular, the choice of the scope, allocation method and further considerations on water consumption and land use indicators have a great significance on the results of the studies. In order to provide with a fair representation of wool environmental impacts, the whole life-cycle should be taken into account, and methodological choices, such as the scope definition and allocation methods are to be clearly stated. The current tools that are the most widely used in the textile industry to rank fibres according to their sustainability performance are not suitable for wool due to unresolved methodological issues. Indeed, the impact categories that are taken into account in those tools are disadvantageous for wool compared to other alternative fibres, especially regarding water consumption and land use. This thesis also explores the construction of a single score based on the eco-costs of environmental impacts as a more suitable option to build a representative tool.

In 2019, the cement industry used 280 million tons of oil equivalent, contributing to 7% of totalindustrial energy consumption. This resulted in 2.4 billion tons of CO2 emissions, constituting26% of the industrial sector’s CO2 output and 7% of global energy-related emissions. On theother hand, It is affordable, safe, and readily available, thanks to its construction error resistance. C3C is a company that takes advantage of waste concrete that has been produced and useit to mold concrete blocks that has different functions. This is a big environmental benefit. Themain function of these blocks has been to function as temporary or permanent partitions walls orsafety walls for accidental loads. The aim of this study is to investigate the feasibility and performance of a temporary office structure that is built majorly out of these C3C lego blocks froma comfort, stability and sustainability point of view. This data aids construction professionalsseeking cost-effective alternatives to traditional methods. Retrofitting and cascading offer economic and environmental benefits. Our goal is to discover innovative, sustainable constructionapproaches for future generations. The results show the importance of insulation positioning forthe comfort point of view. To ensure stability and analyse if the separation of the blocks occur,four RFEM models are made with focus on the tensile stresses and uplifting deflection of thewalls. In conclusion, this study provides ideas on how to design a temporary structure usingC3C lego blocks.Keywords: Concrete blocks, C3C blocks, FE models, life cycle analysis, mechanical connections, CO2 emissions.

This research is conducted to have a better understanding on the future develop- ment of bioplastics and their environmental impacts. This research first studies the future consumption and waste of bioplastics till 2050 by material flow analysis (MFA).  Life cycle assessment is used to assess the environment impacts of three plastics (bio-PET, PEF and petrol-PET).  The total consumption of bioplastics will be near 5 million tons in 2050 and the waste will be near 4 million tons.  The environment of PEF is the highest among the compared plastic types; Coal as the energy input has the would affect the environment more than other two energy inputs;  Sugarcane has the lowest environment impacts among three raw materials. / Denna forskning genomförs för att få en bättre förståelse för den framtida utvecklingen av bioplaster och deras miljöpåverkan. Först studeras den framtida förbrukningen och avfallet av bioplaster fram till 2050 med hjälp av materialflödesanalyser (MFA). Förbrukningen av bioplaster analyseras för olika tillämpningar. ODYM-modellen används för att beräkna MFA. Två parametrar används som indata i modellen. Den ena är den framtida bioplastförbrukningen som beräknas genom att världsbefolkningen multipliceras med den genomsnittliga produktionskapaciteten per capita, och den andra är livslängden per tillämpning. Tolv bioplasttyper har valts ut för denna analys. Dessa plaster är bio-PET, bio-PE, bio-PA, PTT, PEF, bio-PUR, bio-PP, PLA, PHA, PBAT, PBS och PCL. Den framtida konsumtionen av bioplaster och avfallsmängderna kommer att fortsätta att öka. Den totala förbrukningen av bioplaster kommer att vara nära 5 miljoner ton år 2050 och avfallet kommer att vara nära 4 miljoner ton. Den totala förbrukningen av biopur kommer att vara den högsta av alla elva bioplaster. Den tillämpning där förbrukningen av bio-PA är störst är konsumtionsvaror och beläggningar. Bio-PET kommer också att användas i stor utsträckning som förpackningsmaterial. Livscykelanalys används för att bedöma miljöpåverkan från tre plaster (bio-PET, PEF och petrol-PET). Bedömningen genomförs med hjälp av elva scenarier som är indelade i tre grupper: olika energitillgångar, inklusive kol, hy- dropower och naturgas, och global blandad energi; olika produkter, inklusive bio-PET, PEF och petrol-PET; olika råvaror: sockerrör från Brasilien, majs från USA och potatis från Schweiz. Denna bedömning kvantifieras i sex konsekvenskategorier: global uppvärmning, markanvändning, vattenförbrukning, människors hälsa, ekosystem och markanvändning. PEF:s miljöpåverkan är störst bland de jämförda plasttyperna, kol som energibärare påverkar miljön mer än de andra två energibärarna och sockerrör har den lägsta miljöpåverkan bland de tre råvarorna.

Solar photovoltaic (PV) generation has been gaining popularity as low carbon energy technology in the face of the global climate change. However, conventional utility-scale PV requires large swaths of land to be occupied for decades which prevents the land from producing food or performing vital ecosystem services. Co-location of PV with crop cultivation is an emerging strategy for mitigating the land use of PV. In order to optimize this strategy, the impact of the plant growth-related soil properties need to be quantified. To this end, the first portion of the thesis investigated the impacts on the soil properties in a re-vegetated solar PV facility in Boulder, Colorado, which was the oldest vegetation-PV co-location site in the world. The second portion of the thesis uses a life cycle analysis (LCA) approach to test the feasibility of co-location of model crop cultivation and solar PV electricity generation in rural Indonesia, and it is the first study to use the LCA study of the co-located solar in the tropics. The first approach revealed that the soil hydrology, grain size distribution, and total carbon and nitrogen are significantly altered from their original state by the construction and presence of photovoltaic arrays, and that those properties had not been restored to their pre-construction levels despite the fact that ten years had passed since re-vegetation of the PV array. The persistence of the altered soil properties meant that the designs regarding re-vegetation or co-location of PV with crops would have to be considered at the beginning of the construction of the PV to minimize the impact on the soil and the existing vegetation. Furthermore, soil moisture was the highest in the soil underneath the western edge of the PV panels, where the western tilt of the PV panel had concentrated the rainfall. The heterogeneity in soil hydrology created by the panels could be manipulated to benefit the growth of vegetation within the PV array. The LCA approach revealed that a hectare of PV arrays with full module density would carbon offsets against diesel electricity generation and the grid, and that the annual supply of electricity from the PV could satisfy the demand of a typical rural Indonesian village several times over. However, the high capital expenditure of solar mean that co-location with full PV module density would not be economically feasible, even with the income stream from the co-located crop cultivation. In order to reduce the capital expenditure, the PV module density for co-location was reduced to half. The combination of reduced capital expenditure and the income stream from the crop made the co-located land use significantly less costly. Additionally, the rural electrification would be able to provide secondary socioeconomic benefits such as avoidance of health costs through operation of public health infrastructures, increased standard of living, and secondary income opportunities from processing of raw materials. However, better subsidies for renewables, specialized loan structures for small-scale renewable systems, and a culture of co-operation between small landholders would need to be implemented before the co-located system becomes affordable to the inhabitants in rural Indonesian villages. / Geology

Today, we live according to the linear economy which depletes the planet's resources and gives rise to large amounts of waste. The circular economy, on the other hand, can be seen as a kind of cycle where the extraction of raw materials is minimized, and reuse is to be maximized. The generation of waste should preferably be avoided. This study aims to investigate how circular micro-enterprises engage with the principles of the circular economy and to identify any associated difficulties or challenges connected to circular economy. The study also examines whether these companies utilize specific tools to measure their circularity. Four companies were interviewed through questionnaires and semi-structured interviews, and the data was analyzed using thematic analysis as a guiding framework. The findings revealed several challenges associated with implementing circular economy practices, including issues related to transportation and behavior patterns. Furthermore, the majority of the four respondents reported not using any specific tools to measure their circularity, although some companies employ life cycle analysis to assess the environmental impact of their products or services. There is a clear need for the development of standardized tools that facilitate the assessment of circularity for companies, enabling easy comparison and evaluation of progress in adopting circular economy principles.

Current thinking on the best propulsion system for a next-generation supersonic cruising (Mach 2 to Mach 4) aircraft is a mixed-flow turbofan engine with afterburner. This study investigates the performance increase of a turbofan engine through the use of isothermal combustion inside the high-pressure turbine (High-Pressure Turburner, HPTB) as an alternative form of thrust augmentation. A cycle analysis computer program is developed for accurate prediction of the engine performance and a supersonic transport cruising at Mach 2 at 60,000 ft is used to demonstrate the merit of using a turburner. When assuming no increase in turbine cooling flow is needed, the engine with HPTB could provide either 7.7% increase in cruise range or a 41% reduction in engine mass flow when compared to a traditional turbofan engine providing the sane thrust. If the required cooling flow in the turbine is almost doubled, the new engine with HPTB could still provide a 4.6% increase in range or 33% reduction in engine mass flow. In fact, the results also show that the degradation of engine performance because of increased cooling flow in a turburner is less than half of the degradation of engine performance because of increased cooling flow in a regular turbine. Therefore, a turbofan engine with HPTB will still easily out-perform a traditional turbofan when even more cooling than currently assumed is introduced. Closer examination of the simulation results in off-design regimes also shows that the new engine not only satisfies the thrust and efficiency requirement at the design cruise point, but also provides enough thrust and comparable or better efficiency in all other flight regimes such as transonic acceleration and take-off. Another finding is that the off-design bypass ratio of the new engine increases slower than a regular turbofan as the aircraft flies higher and faster. This behavior enables the new engine to maintain higher thrust over a larger flight envelope, crucial in developing faster air-breathing aircraft for the future. As a result, an engine with HPTB provides significant benefit both at the design point and in the off-design regimes, allowing smaller and more efficient engines for supersonic aircraft to be realized. / Ph. D.

Packaging sustainability has become one of the most notable issues of this era. Many researchers have endeavored to characterize or compare the environmental burdens of a single level of packaging, such as primary, secondary, or tertiary packaging. However, goods are often handled, stored, and transported through the supply chain system in unit load form consisting of pallets, corrugated boxes, and load stabilizers. Hence, it is important to holistically understand the environmental impact of not only individual packaging levels, but also the unit load form. We can use the interactions between the unit load components to reduce the environmental burdens generated in the supply chain system. Past studies discovered that pallet top deck thickness has a huge effect on corrugated box compression strength. Using this knowledge, researchers were able to optimize the cost of unit loads by increasing pallet top deck thickness and reducing the board grade of corrugated boxes. This study (1) further discovered how different unit load design factors, such as initial top deck thickness, pallet wood species, box size, and board grade, affect the performance of the previously proposed unit load design optimization method, and (2) we investigated if the unit load optimization method could also enhance unit load sustainability. The study's first phase identified that the benefits of increasing top deck thickness were more pronounced as the initial top deck thickness decreased, higher board grade boxes were initially utilized, and smaller-sized boxes were used. The second phase of this study showed that increasing top deck thickness and reducing the board grade of corrugated boxes could offset environmental impacts by as much as 23%. Environmental benefits were mostly achieved by reducing the amount of relatively more-processed materials in the corrugated boards. This phase also provided preliminary unit load conditions as guidance for unit load professionals to estimate the possibility of optimizing their unit load design in an environmentally beneficial way. / Master of Science / Sustainability-minded individuals, industries, and policymakers recently recognized the environmental burdens associated with packaging as a critical concern to society. Many initiatives and studies have been conducted to prevent and reduce the environmental impacts of individual packaging systems, such as corrugated boxes, plastic bottles, and pallets. However, not many efforts have been made to enhance the environmental performance of a whole unit load, which is the most common distribution packaging form used to transport and store goods. It is essential to understand the physical interactions between unit load components, such as corrugated boxes and pallets, in order to improve a unit load's environmental performance effectively. The unit load optimization concept introduced in the past study, which showed that increasing top deck thickness can reduce the needed board grade of corrugated boxes, was further investigated and utilized in this study to offset the environmental burdens of a unit load by substituting different materials used. To assess the environmental performance of that unit load design optimization method, this study first endeavored to understand further how various unit load design factors could affect the result of unit load optimization, and second, we analyzed many different scenarios using a life cycle analysis method. The study found that the unit load design method that uses deck board thickness to change the amount of corrugated board needed had more potential for lighter pallets with thinner deck boards carrying heavier loads. The results also showed that increasing top deck board thickness and reducing the board grade of the corrugated board could improve the environmental performance of a unit load when the corrugated material is sufficiently substituted with a reasonable amount of pallet material.

With rising awareness that future generations may not have access to the resources and quality of life that exist today, sustainable development has become a priority within civil engineering. One important component of sustainable development is environmental stewardship, which concerns both the resources taken from the environment, and the wastes and byproducts emitted to the environment. To facilitate more sustainable development, environmental accounting is necessary within civil and geotechnical engineering design and construction. Historically, geotechnical practice has focused on maximizing design performance while minimizing monetary costs, and well established methods exist for quantifying these factors. Quantitative consideration of environmental consequences has seldom played a large role in geotechnical design and construction, and clear guidelines and a methodology for such an assessment are not available within the geotechnical profession. Therefore, this research has focused on establishing a method for quantitative streamlined environmental Life Cycle Analysis of energy and carbon dioxide (CO2) emissions for geotechnical ground improvement works, known as the Streamlined Energy and Emissions Assessment Model (SEEAM). The boundaries for the SEEAM extend from raw material extraction through the completion of construction, including the energy and CO2 emissions associated with construction materials, construction site operations, and the transportation of construction materials and wastes. The methodology relies on energy and CO2 emissions coefficients, which represent typical industry average values and not necessarily the specific processes contributing to a project. Therefore, there is uncertainty in SEEAM analyses, which is addressed via a Monte Carlo simulation framework that assumes the energy and CO2 emissions coefficients each follow a lognormal distribution. Data sets of total energy and CO2 emissions generated by the Monte Carlo simulation framework with the SEEAM may be used to statistically compare the energy and CO2 emissions of different geotechnical design alternatives. Such comparisons can help facilitate designing for minimum environmental consequences, thus advancing sustainable development within geotechnical engineering. For clarity, the development and application of the SEEAM is illustrated using two different geotechnical case history projects, including rehabilitation of levee LPV 111 in New Orleans, LA, and the construction of foundations for a replacement dormitory on the Virginia Tech campus. / Ph. D.

The life cycle analysis compares the environmental impacts of catalytic converters and the effects of not using these devices. To environmentally evaluate the catalytic converter, the emissions during extraction, processing, use of the product are considered. All relevant materials and energy supplies are evaluated for the catalytic converter. The goal of this life cycle is to compare the pollutants of a car with and without a catalytic converter. Pollutants examined are carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), and nitrogen oxides (NOx). The main finding is that even considering materials and processing, a catalytic converter decreases the CO, HC and NOx pollutant emissions. The CO2 emissions are increased with a catalytic converter, but this increase is small relative to the overall CO2 emissions. The majority of catalytic converter pollutants are caused by the use phase, not extraction or processing. The life cycle analysis indicates that a catalytic converter decreases damage to human health by almost half, and the ecosystem quality damage is decreased by more than half. There is no damage to resources without a converter, as there are no materials or energy required; the damages with a converter are so small that they are not a significant factor. Overall, catalytic converters can be seen as worthwhile environmental products when considering short term effects like human health effects of smog, which are their design intent. If broader environmental perspectives that include climate change are considered, then the benefits depend on the weighting of these different environmental impacts. / Master of Science