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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Avaliação do ciclo de vida de blocos de concreto do mercado brasileiro: alvenaria e pavimentação. / Life cycle assessment of concrete blocks on the Brazilian market masonry and pavement.

Lidiane Santana Oliveira 06 July 2015 (has links)
A construção civil é responsável por relevante impacto ao meio ambiente, da extração das materiais-primas até a disposição dos seus resíduos em aterros. A avaliação do ciclo de vida (ACV) é uma ferramenta que possibilita a estimativa dos impactos ambientais potenciais do setor de forma sistemática. A simplificação da ACV, pelo uso de dados secundários e redução do escopo do estudo, facilita sua implementação como ferramenta de promoção da sustentabilidade. O objetivo dessa dissertação é estimar faixas dos cinco principais indicadores do setor de blocos de concreto do mercado brasileiro pela simplificação da ACV: consumo de materiais, energia incorporada, emissão de CO2, água e geração de resíduos. Este estudo foi o piloto do Projeto ACV Modular, iniciativa do Conselho Brasileiro de Construção Sustentável em parceria da Associação Brasileira de Cimento Portland e da Associação Brasileira da Indústria de Blocos de Concreto. O inventário foi desenvolvido com 33 fábricas localizadas em diferentes regiões do Brasil, estas sendo responsáveis por aproximadamente 50% da produção nacional. Os produtos selecionados foram blocos para pavimentação e alvenaria (estruturais e de vedação) considerados mais representativos no mercado. A fronteira do sistema adotada foi do berço ao portão da fábrica. O indicador de consumo de materiais não foi apresentado para garantir a confidencialidade dos dados das empresas, pois o teor de cimento foi dado direto informado no formulário. O indicador de resíduos não pode ser gerado devido a diferentes interpretações adotadas pelos fabricantes ao registrar seus dados. O indicador de água, apesar de incluir todo o consumo informado pela fábrica, apresentou valores muito baixos, alguns próximos a zero. O consumo de cimento, não o teor de clínquer, foi responsável por parcela significativa do CO2 e da energia incorporada do bloco, com participação de 62 a 99% das emissões de CO2. Assim, entre as empresas analisadas, mesmo com igual rota tecnológica, os insumos utilizados, a formulação do concreto, a eficiência de compactação da vibro prensa e o sistema produtivo tiveram maior influência nos indicadores de materiais, energia e CO2. / The civil construction is responsible for significant environmental impact from the extraction of raw materials to the disposal of their waste in landfills. The life cycle assessment (LCA) is a tool that enables the estimative of the potential environmental impacts of a sector systematically. Simplification of LCA, the use of secondary data and reduce the scope of the study, facilitates its implementation as a tool for promoting sustainability. The purpose of this dissertation is to estimate ranges of the five main indicators of the concrete block industry in the Brazilian market by simplifying the LCA: consumption of materials, embodied energy, CO2 emissions, water and waste generation. This study was the pilot of Modular LCA Project, an initiative of the Brazilian Council for Sustainable Construction (CBCS) in partnership with the Brazilian Portland Cement Association (ABCP) and the Brazilian Association of Concrete Blocks Industry (BlocoBrasil). The inventory was raised from 33 factories located in different regions of Brazil, that accounting for approximately 50% of national production. The products selected were paving and masonry blocks considered most representative in the market. The boundary system adopted was from cradle to factory gate. The indicator material consumption has been omitted to ensure the confidentiality of company data, as the cement content was raised directly by the companies. The waste indicator cannot be generated due to different interpretations adopted by companies to register their data. The water indicator, although it includes all the consumption reported by the factory, showed very low values, some near zero. Cement consumption, not the clinker content, accounted for a significant portion of CO2 emission and embodied energy, accounting 62-99% of CO2. Thus, among the analyzed factories, even with the same technological route, the inputs, the concrete formulation, the compression efficiency of vibro press and the production system had a greater influence on indicators of materials, energy and CO2.
12

Skillnaden i koldioxidutsläpp mellan limträ och stål : En studie som jämför två olika stommaterial / A study that compares two different frame materials

Dicksen, Jesper January 2021 (has links)
Idag görs livscykelanalyser (LCA) för att identifiera de byggkomponenter somorsakar stora koldioxidutsläpp i byggbranschen.Syftet med denna studie är att med hjälp av livscykelanalysverktyget One ClickLCA jämföra hur stora koldioxidutsläpp som bildas av materialen i enlimträstomme, som tillhör en inomhusarena jämfört med materialen i en fiktivstålstomme, som är dimensionerad för att klara samma laster och funktion somlimträstommen. Detta görs i syfte att lyfta fram skillnaderna mellankoldioxidutsläppen i produktskedet (A1-A3) mellan en limträstomme och enstålstomme.En konstruktör har konstruerat stålstommen för jämförelsen. Konstruktören togfram dimensionerna och byggmaterialen, men stålstommen blev inte tillräckligtgenomarbetad och projekterad för att jämförelsen skulle kunna göras direkt.I One Click LCA behövs mängderna och byggkomponenterna för båda stommarnaför att kunna göra fullständiga livscykelanalyser. Med mängder menas volymeroch vikter för byggkomponenterna. I studien saknades från början mängder förvissa av byggkomponenterna och en del av syftet blev därför att ta fram allamängder för stommarna. För att få rätt mängder i studien användes bland annat tvåprogram, Bluebeam och Excel. Med dessa program togs längdmåtten för olikabyggkomponenter från ritningar. Tillsammans med de övriga uppgifterna ombyggkomponenterna kunde mängderna sedan tas fram.I One Click LCA behöver resurser väljas. Dessa kan vara kopplade till specifikabyggkomponenter och innehåller data om hur stora koldioxidutsläpp sombyggkomponenter orsakar. Med byggkomponenter och mängder som grund valdessedan resurser i One Click LCA. När resurser väljs räknar programmet ut hur storakoldioxidutsläpp som bildas i produktskedet (A1-A3) för byggkomponenterna.Med mängder och resurser kunde två resultat erhållas i programvaran. Resultatetvisar att 55 ton koldioxid bildas av limträstommen och 779,9 ton koldioxid bildasav stålstommen. I stålstommen är det fackverken som orsakar mestkoldioxidutsläpp och i limträstommen är balkarna i högdelen av inomhusarenansom orsakar mest koldioxidutsläpp. / Today, life-cycle assessment (LCA) are performed to identify the buildingcomponents that cause large carbon dioxide emissions in the construction industry.The purpose of this study is to use the life-cycle assessment tool One Click LCA tocompare how large carbon dioxide emissions are formed by the materials in aglulam frame, which belongs to an indoor arena compared to the materials in afictitious steel frame, which is dimensioned to withstand the same loads andfunction as the glulam frame. This is done in order to highlight the differencesbetween the carbon dioxide emissions in the product phase (A1-A3) between aglulam frame and a steel frame.A designer has designed the steel frame for comparison. The designer producedthe dimensions and building materials, but the steel frame was not sufficientlyworked out and projected for the comparison to be made directly.In One Click LCA, the quantities and building components for both frames areneeded to be able to make complete life-cycle assessment. By quantities is meantvolumes and weights for the building components. The study initially lackedquantities for some of the building components and part of the purpose wastherefore to produce all quantities for the frames. To get the right amounts in thestudy, two programs were used, Bluebeam and Excel. With these programs, thelength measurements for different building components were taken from drawings.Together with the other information about the building components, the quantitiescould then be produced.In One Click LCA, resources need to be selected. These can be linked to specificbuilding components and contain data on how large carbon dioxide emissions thatbuilding components cause. Based on building components and quantities,resources were then selected in One Click LCA. When resources are selected, theprogram calculates how large carbon dioxide emissions are formed in the productphase (A1-A3) for the building components. With quantities and resources, tworesults could be obtained in the software. The results show that 55 tonnes ofcarbon dioxide are formed by the glulam frame and 779.9 tonnes of carbon dioxideare formed by the steel frame. In the steel frame, it is the trusses that cause themost carbon dioxide emissions and in the glulam frame, the beams in the upperpart of the indoor arena cause the most carbon dioxide emissions.
13

An alternative future for shipping – the way there : Risks and benefits of energy efficiency measures and alternative fuels for CO2 reduction in

Sunneland, Johanna, Gutiérrez Dufourq, María Sofía January 2018 (has links)
Shipping is the world’s largest mode of transportation, considering mass moved a distance: it is the most e˙effective way to carry large volumes far. In order for the shipping industry to keep its position and develop even further, efforts are made to increase efficiency and reduce the environmental footprint from the industry. More efficient ships, reduced fuel consumption, use of alternative fuels and exhaust gas treatment are some of the choices to reduce shipping’s environmental footprint and achieve the sustainability goal established by EU and enforced by the International Maritime Organization.Throughout the thesis, en evaluation of 18 energy efficiency measures and 4 alternative fuels is performed. Energy efficiency measures reduce a ship’s fuel consumption and alternative fuels substitutes fossil fuels with higher content of environmentally harmful content. The measures and fuels, covered in the study, are evaluated for nine representative container ship´s. Data from year 2016 are used for the nine container ships. The current procedure followed for new investments is analyzed for all measures and fuels for each ship, focused on the financial study of each measure and fuel. The results are then included in a risk and benefit analysis that introduces external aspects, not included in the traditional financial evaluation, that include: those that influence the ship and the ship’s environment and those affected by the ship’s operations.The main goal is to evaluate the possibilities to reduce emissions by considering these aspects and involve more stakeholders in the investment of measures and fuels for shipping to keep its position as the most efficient mode of transportation.
14

Green consumption energy use and carbon dioxide emission

Alfredsson, Eva January 2002 (has links)
The aim of this thesis is to explore the quantitative potential to reduce energy requirements and CO2 emissions through changed patterns of consumption, given unchanged levels of consumption expenditure. The thesis question is analysed using a systems analysis approach which in this case means that life cycle assessment data on energy requirements and CO2 emissions related to household consumption are combined with a financial and behavioural analysis to make sure that the budget constraint is kept and that both the first and second order effects of adopting a green consumption pattern are analysed. The budget constraints are kept using a general linear model. By using marginal propensities to spend to direct the reallocation of saved or deficit money calculated utility is maintained as far as possible. Further, investigations explore the impact of individual household demographic characteristics and geographic context on household consumption patterns, energy requirements and CO2 emissions. The key result of this thesis is that changed household behaviour, choosing “green“ products and energy efficient technology will not make a big difference. What can be achieved in the short time perspective by adopting an almost completely green consumption pattern and energy efficient technology is a reduction of energy requirements by around 8% and CO2 emissions by around 13%. With a longer time perspective and further technological change that provides additional possibilities to move consumption patterns in a greener direction, the effect on energy requirements and CO2 emissions is still fairly small. By 2020, the potential to reduce energy requirements is around 13% and CO2 emissions around 25%. In the most extreme scenario (2050), the scope for reducing energy requirements is 17% and for CO2 emissions 30%. All these reductions will be outpaced by growth in income almost as soon as they are implemented. Of policy relevance the results reveal that very limited impact can be expected by a policy relying on greener consumption patterns, whether adopted voluntarily or as a result of incentives such as tax changes. Such a policy cannot achieve more than a small and temporary reduction to growth in energy requirements and CO2 emissions. It is also shown that, prescribing specific consumption patterns as a means of reducing energy requirements and CO2 emissions has to be done with care. This is illustrated by one of the experiments in which adopting a partly green consumption pattern, a green diet, in fact increased total energy requirements and CO2 emissions. This, and the results of all the other experiments show the importance of applying a systems approach. It demonstrates that life cycle data alone are irrelevant for assessing the total effects of adopting green consumption patterns. Further research on the potential to reduce energy requirements and CO2 emissions thus primarily needs to better capture system wide effects rather than to improve on, and fine tune the measurement of the energy requirements and CO2 emissions related to individual products.
15

Användning av byggnadsinformationsmodellering (BIM) för effektivare klimat- och livscykelanalyser av byggnadskonstruktioner / The use of building information modeling (BIM) to achieve efficient life cycle assessments of buildings

Rodriguez Ewerlöf, Ivana January 2018 (has links)
Byggprocesser och produktionen av byggmaterial orsakar stora delar av världens och Sveriges växthusgasutsläpp. För att uppnå en hållbar utveckling är det av stor vikt att minska klimatpåverkan från byggnadskonstruktioner. Genom att göra klimat- och livscykelanalyser av byggnader i tidiga designskeden ökar möjligheten att påverka design, material- och produktval för att minska klimatpåverkan. I denna studie undersöktes hur byggnadsinformationsmodeller (BIM) och BIM-metodik kan användas för ökade möjligheter att effektivt utföra klimat- och livscykelanalyser av ingående byggnadsmaterial iterativt under projekteringsprocessen. Två 3D-modeller importerades till två verktyg för klimat- och livscykelanalyser, Bidcon och One Click LCA. Mängdavtagningen från objekten i modellen till båda LCA-verktygen fungerade automatiskt medan kopplingen mellan objekten och databaser med miljöpåverkansdata för byggobjekt och material innebar mycket handpåläggningsarbete. Processerna förutsätter att modellerna innehåller någon information om de ingående materialen i modellens objekt, vilket därför bör kravställas under projekteringen. För att kopplingen mellan materialbeskrivningar och databaser i LCA-programmen ska ske mer automatiskt bör materialen eller objekten benämnas standardiserat, till exempel med BSAB-koder, ett klassifikationssystem från Svensk Byggtjänst. Benämningarna bör sedan kunna kopplas automatiskt till poster i databaser för effektivare klimat- och livscykelanalyser.  Även intervjuer utfördes, i syfte att undersöka hur metodiken för integrering av BIM och LCA kan tillämpas i byggprojekt. Möjligheten att tillämpa detta i konsultföretag beror på beställarens krav samt i vilka skeden och discipliner konsulterna arbetar. Integreringsprocesser av BIM- och LCA-verktyg borde kombineras med interdisciplinära möten för bättre resultat. Detta tillsammans med ökad efterfrågan på klimat- och livscykelanalyser, exempelvis för att uppnå miljöcertifieringar, kan öka motivationen att använda metodiken. På så sätt kan byggnadsinformationsmodellering användas för effektivare klimat- och livscykelanalyser vilket bidrar till minskad klimatpåverkan från byggnadskonstruktioner. / Construction processes and the production of building material cause a large part of the emissions of greenhouse gases around the world. To achieve a sustainable development it is of great importance to reduce emissions from construction projects. Doing climate analyses and life cycle assessments of building materials during early design phases could enable more sustainable design and material choices. This thesis focuses on Swedish conditions. During this study it was investigated how Building Information Modeling/Management (BIM) can be used to improve possibilities of doing efficient life cycle assessments (LCA) of buildings and included materials, during the whole design phase. Two 3D building models were transferred to two software tools, Bidcon and One Click LCA, for climate analysis and life cycle assessment of the building components. Quantity take-off from the model objects to the tools worked automatically while the connection between the material descriptions and databases inside the tools had to be done manually. The process requires information about the materials in the model to work. To make the connections more automatic, material descriptions need to be more standardized and connect to entries in the databases. Moreover interviews were held to investigate how the methods of integrating BIM with LCA can be used in construction projects. For consulting firms this depends on the demands from the client and which stages of the project the consultants work in. LCA-methods based on BIM should be combined with interdisciplinary meetings for better results. This together with an expanding demand for LCA could increase the motivation to use these methods, which enables reduction of climate impact from buildings.
16

Study of crack width within a suspended concrete slab with different amount of cement clinker considering lower climate impact

Feizi, Sedige, Khan, Fateha Yasmin January 2018 (has links)
This master thesis investigates the possibility of using a concrete recipe with only 70 % cement clinker for a building project named Gretas Glänta, regarding the demands of cracking for a suspended slab. The requirement to fulfill was a maximum crack width of 0.2 mm due to drying shrinkage and long- term loading. The purpose of using a lower amount of cement clinker in the concrete mix is to reduce the climate impact from the concrete. The thesis considers material testing and modelling of different concrete recipes with variation of the amount of cement clinker. Fly ash was used as the alternative binder. A total of five concrete mixes was tested. One mix with 100% cement clinker was through laboratory testing compared to mixes with 85 % and 70 % cement clinker content. A concrete mix with only 50 % cement clinker was also tested, but this mix is today not allowed according to the concrete standards, but was included in the study to test different material properties of the fresh and hardened concrete. All concrete mixes were tested with the effectivity factor 1, except for the recipe with 70 % cement clinker, which was tested for effectivity factors of 1 and 0.4. The performed study showed that the concrete mix 4 with 70 % cement clinker and with the effectivity factor 0.4 reached the strength class C35/45 after 28 days and also fulfilled the specified requirement of a maximum crack width of 0.2 mm due to drying shrinkage and long-term loading. Water permeability test showed that the concrete mix with 70 % cement clinker and an effectivity factor of 0.4 was waterproof. The concrete mix 3 with 70 % cement clinker and the effectivity factor 1 reached a strength class C30/37. The concrete mix 1 with 100 % cement clinker obtained the highest strength class C50/60 and the mix 2 with 85 % cement clinker reached strength class C45/55. The concrete mix 5 with 50 % cement clinker reached the strength class C20/25 which is the lowest strength class among the tested recipes. All the concrete recipes seemed to be waterproof according to the water permeability test. A background description of carbon dioxide emission from concrete and cement production is presented in the report. Research about ongoing methods to minimize the emission from concrete and cement industry is also summarized. FE-modelling with the software FEM-design and analytical calculations were performed to investigate the crack width due to drying shrinkage and long-term loading for the slab, for concrete mix 2 with 85 % cement clinker with effectivity factor 1 and mixes 3 and 4 with 70 % cement clinker and effectivity factors of 1 and 0.4. The properties obtained from the laboratory tests were used in the modelling and analytical calculations. Results from FEM-design and analytical calculations showed that concrete mixes 3 and 4 with 70 % cement clinker and effectivity factors of 1 and 0.4, and the concrete mix 2 with 85 % cement clinker with effectivity factor 1, fulfilled the demand on crack width. The calculation was not performed for concrete mixes 1 and 5 with 100 % and 50 % cement clinker, respectively, because they were not to be used in the building project. The results from the performed study showed that concrete mix 4 with 70 % cement clinker and an effectivity factor of 0.4 can be used in the building project Gretas Glänta in order to lower the climate impact from the concrete. / Examensarbetet undersöker möjligheten att använda ett betongrecept med endast 70 % cementklinker för ett husbyggnadsprojekt kallat Gretas Glänta med hänsyn till krav på sprickbildning i en fribärande platta. Kravet som ska uppfyllas är en sprickvidd på max 0.2 mm med hänsyn till krympning och långtidsbelastning. Syftet med att använda en lägre andel cementklinker i betongblandningen är att minska klimatpåverkan från betongen. Examensarbetet består av materialförsök och konstruktionsteknisk modellering för olika betongrecept, där andelen cementklinker varieras. Flygaska användes som alternativt bindemedel. Totalt undersöktes fem betongmixer. En mix med 100 % cementklinker jämfördes genom laboratorietestning med motsvarigheter med 85 % och 70 % cementklinkerinnehåll. Ett betongrecept med 50 % cementklinker undersöktes också i detta examensarbete, trots att detta idag inte tillåts enligt betongstandarderna, men inkluderades i studien för att testa olika materialegenskaper i färskt och hårdnat tillstånd. Alla betongmixerna testades med effektivitetsfaktorn 1 förutom receptet med 70 % cementklinkerandel som testades för både 1 och 0.4 i effektivitetsfaktor. Den genomförda studien visade att betongmix 4 med 70 % cementklinker och med effektiviseringsfaktor 0.4 uppnådde hållfasthetsklass C35/45 efter 28 dagar och uppfyllde också angivet krav på maximal sprickbredd 0,2 mm med hänsyn till krympning och långtidslast. Vattenpermeabilitetstest visade att betongmixen med 70 % cementklinker och effektiviseringsfaktor 0.4 var vattentätt. Betongmix 3 med 70 % cementklinker och effektivitetsfaktor 1 uppnådde hållfasthetsklass C30/37. Betongmix 1 med 100 % cementklinker erhöll den högsta hållfasthetsklassen C50/60 och betongmix 2 med 85 % cementklinker gav hållfasthetsklass C45/55. Betongmix 5 med 50 % cementklinker uppnådde hållfasthetsklass C20/25 vilket var den lägsta av de testade betongrecepten. Alla betongrecepten verkade ge vattentät betong enligt vattenpermeabilitetstest. En bakgrundsbeskrivning av koldioxidutsläpp från betong- och cementproduktion genomförs i rapporten. Forskning om pågående metoder för att minimera utsläppen från betong- och cementindustrin sammanfattas också. FE-modellering med programmet FEM-design och analytiska beräkningar utfördes för att undersöka sprickbredden med hänsyn till krympning och långtidslast för betongplattan för betongmix 2 med 85 % cementklinker och effektiviseringsfaktor 1 och betongmixerna 3 och 4 med 70 % cementklinker och effektiviseringsfaktorerna 1 och 0.4. Egenskaperna som erhölls i laboratorietesterna användes i modellerings och de analytiska beräkningarna. Resultat från FEM-design och analytiska beräkningarna visade att betongmixerna 3 och 4 med 70 % cementklinker med effektiviseringsfaktorerna 1 och 0.4 och betongmix 2 med 85 % cementklinker och effektiviseringsfaktor 1 uppfyllde kravet på sprickbredd. Beräkningen utfördes inte för betongmixerna 1 och 5 med 100 % cementklinker och 50 % cementklinker då de inte var aktuella för att användas i bostadsprojektet. Resultaten från den genomförda studien visade att betongmix 4 med 70% cementklinker och med en effektivitetsfaktor 0.4 kan användas i husbyggnadsprojektet Gretas Glänta för att sänka klimatpåverkan från betongen.

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