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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.
51

New Framework for Real-time Measurement, Monitoring, and Benchmarking of Construction Equipment Emissions

Heidari Haratmeh, Bardia 29 June 2014 (has links)
The construction industry is one of the largest emitters of greenhouse gases and health-related pollutants. Monitoring and benchmarking emissions will provide practitioners with information to assess environmental impacts and improve the sustainability of construction. This research focuses on real-time measurement of emissions from non-road construction equipment and development of a monitoring-benchmarking tool for comparison of expected vs. actual emissions. First, exhaust emissions were measured using a Portable Emission Measurement System (PEMS) during the operation of 18 pieces of construction equipment at actual job sites. Second-by-second emission rates and emission factors for carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons were calculated for all equipment. Results were compared to those of other commonly used emission estimation models. Significant differences in emission factors associated with different activities were not observed, except for idling and hauling. Moreover, emission rates were up to 200 times lower than the values estimated using EPA and California Air Resources Board (CARB) guidelines. Second, the resulting database of emissions was used in an automated, real-time environmental assessment system. Based on videos of actual construction activities, this system enabled real-time action recognition of construction operations. From the resulting time-series of activities, emissions were estimated for each piece of equipment and differed by only 2% from those estimated by manual action recognition. Third, the actual emissions were compared to estimated ones using discrete event simulation, a computational model of construction activities. Actual emissions were 28% to 144% of those estimated by manual action recognition. Results of this research will aid practitioners in implementing strategies to measure, monitor, benchmark, and possibly reduce air pollutant emissions stemming from construction. / Master of Science
52

Shear behaviour of reinforced construction and demolition waste-based geopolymer concrete beams

Aldemir, A., Akduman, S., Ucak, S., Rafet, A., Sahmaran, M., Yildirim, Gurkan, Almahmood, Hanady A.A., Ashour, Ashraf 25 October 2022 (has links)
Yes / Geopolymer concrete is a promising candidate to replace conventional concrete as geopolymer concrete depends on alkali-activated binders instead of Portland cement. The elimination of cement from the mixture results in the reduction of the greenhouse gas release. From the literature, it is known that the micro-scale characteristics of the geopolymer concrete are similar to its counterparts. However, the structural performance of geopolymer elements should be investigated in detail. Therefore, in this study, the structural performance of reinforced geopolymer concrete beams is compared by conducting bending tests to determine the shear behavior of new generation geopolymer concrete produced from entirely construction and demolition wastes (CDW). In these tests, geopolymer concrete with recycled aggregates, geopolymer concrete with natural aggregates, conventional concrete with recycled aggregates, and conventional concrete with natural aggregates are used in order to study the possibility of reaching fully-recycled construction materials. Three different shear-span-to-depth ratios (a/d) are utilized to investigate the different modes of failure. Therefore, the structural performance of beams was, firstly, compared for mixtures without recycled aggregates to control the possible side effects of 100% recycled concrete construction. Load-deflection curves, moment-curvature curves, and crack patterns were utilized to conclude the performance of geopolymer concrete. Test results revealed that geopolymer concrete beams exhibited similar performance to the conventional concrete beams of the same grade. However, the inclusion of recycled aggregates caused a shift in the failure mechanism from shear-dominated to flexure-dominated, especially in specimens with larger a/d ratios. Finally, the capacity prediction performance of current codes, i.e., TS500 and ACI318, are also examined, and the calculations resulted that the current code equations have a percentage error of approximately 55% on average, although TS500 equations performed slightly better. / The authors gratefully acknowledge the financial assistance of the Scientific and Technical Research Council (TUBITAK) of Turkey and the British Council provided under projects: 218M102 and European Union’s Horizon 2020 research and innovation programme under grant agreement No: 869336, ICEBERG (Innovative Circular Economy Based solutions demonstrating the Efficient recovery of valuable material Resources from the Generation of representative End-of-Life building material).
53

The Viability of Earth Construction in Sweden: A Path Towards Sustainable Building Practices

Ljungcrantz, Markus January 2024 (has links)
The escalating environmental crises, marked by rising global temperatures and resource depletion, highlight the urgent need for sustainable alternatives in various sectors, including construction. The EU has set a goal to achieve climate neutrality by 2050, necessitating the adoption of eco-friendly practices and materials. Earth construction, which utilises raw soil-based materials such as mud, sand, and clay, is proposed as a potential solution to the unsustainable methods predominant in today's construction industry. These traditional techniques, rooted in various cultures globally, offer significant environmental benefits due to their low embodied energy, minimal resource depletion, and excellent thermal properties. Despite its historical roots and environmental benefits, contemporary Swedish architecture has not widely adopted earth construction as a prevalent building method. Today the technique faces numerous barriers to widespread adoption in Sweden, including stringent building codes, a lack of education and awareness, and cultural perceptions that view these methods as primitive. This research investigates the viability of earth construction within the Swedish context and explores strategies for its advancement. Through a combination of literature review, expert interviews, participatory workshops with schoolchildren, and hands-on urban living labs, the study aims to provide a comprehensive understanding of the potential for earth construction to contribute to sustainable building practices. The findings suggest that while earth construction can significantly reduce the environmental impact of the construction industry however, large-scale implementation is scarce and requires overcoming regulatory, educational, and cultural challenges. This research contributes to the broader discourse on sustainable construction by highlighting the need for integrated efforts involving education, policy reform, and community engagement to realise the potential of earth construction in achieving the objective set by the EU to become climate neutral by 2050. / De eskalerande miljökriserna, som kännetecknas av stigande globala temperaturer och resursutarmning, understryker det akuta behovet av hållbara alternativ inom olika sektorer, inklusive byggbranschen. EU har satt upp ett mål att uppnå klimatneutralitet till 2050 (Europeiska kommissionen, 2022), vilket kräver införandet av miljövänliga metoder och material. Jordkonstruktion/earth construction, som använder råmaterial baserade på jord såsom lera, sand och silt, föreslås som en potentiell lösning på de ohållbara metoder som dominerar dagens byggindustri. Dessa traditionella tekniker, med rötter i olika kulturer världen över, erbjuder betydande miljöfördelar tack vare deras låga inbyggda energi, minimala resursutarmning och utmärkta termiska egenskaper (Halliday, 2019). Trots dess historiska rötter och miljöfördelar har samtida svensk arkitektur inte i stor utsträckning anammat jordkonstruktion som en utbredd byggmetod. Idag står tekniken inför många hinder för bredare användning i Sverige, inklusive strikta byggregler, brist på utbildning och medvetenhet samt kulturella uppfattningar som ser dessa metoder som primitiva. Denna forskning undersöker jordkonstruktionens genomförbarhet inom svensk kontext och utforskar strategier för dess främjande. Genom en kombination av litteraturstudier, intervjuer med experter, deltagande workshops med skolelever och praktiska urbana levande laboratorier syftar studien till att ge en omfattande förståelse av potentialen för jordkonstruktion att bidra till hållbara byggmetoder. Resultaten tyder på att även om jordkonstruktion kan avsevärt minska byggindustrins miljöpåverkan, är storskalig implementering sällsynt och kräver övervinnande av reglerings-, utbildnings- och kulturella utmaningar. Denna forskning bidrar till den bredare diskursen om hållbart byggande genom att betona behovet av integrerade insatser som involverar utbildning, politisk reform och samhällsengagemang för att realisera potentialen för jordkonstruktion att uppnå det mål som EU satt upp om att bli klimatneutralt till 2050.
54

Challenges and Opportunities of Reusing Materials in Construction (Sweden) : A PEST-SWOT Analysis

Inanloo, Peyman January 2024 (has links)
This thesis explores the challenges and opportunities of reusing construction and demolition waste within Sweden's construction sector, employing a PEST-SWOT analytical framework. The focus is on three primary materials prevalent in residential single-family houses: brick, concrete, and timber. The study identifies key political, economic, social, and technological factors that influence material reuse practices. The analysis highlights substantial barriers including regulatory complexities, lack of incentives, and the tendency to often prioritize new over reused materials due to perceived risks and higher costs associated with reuse. Despite these challenges, the research identifies significant opportunities for advancing material reuse. These include the potential for implementation of technological advancements in material processing, and growing public and governmental support for sustainable construction practices. The thesis goes forward by proposing strategic recommendations aimed at enhancing the adoption of reuse practices, thereby contributing to a more sustainable and resource-efficient construction sector in Sweden. / Demand trust for circular building materials
55

An exploration of the non-tradistional role interactions between professional team memebers in green building design in the construction industry

Kgokong, Tryfina 12 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2012. / The professional team play a critical role during the design phase to ensure the implementation of a green building design, but in what way do they differ from a traditional design team? The research seeks to determine, whether the professional team members need to be specifically alert to green building principles and willing to learn and apply green building principles through an investigation of a commercial project case study. The research design embraces a qualitative approach through the gathering of data on the case study, where project information was examined and the professional team members interviewed. To reinforce the project specific information, professionals in the construction industry were canvassed for their opinions on the awareness of professional team members, and their willingness to learn and apply, green building principles on commercial projects seeking green star rating. The findings from the case study indicate that a non-traditional, integrated design approach stimulated the professional team‟s alertness and willingness to learn and apply green building principles to great success, as the project achieved a four star green rating. The survey found that professional‟s perceived green buildings to have a positive impact on the environment and if possible reverse the harmful effects that conventional buildings have on the environment. Furthermore, professional team‟s early involvement is highly imperative to achieve a green star accreditation. The green design process requires continuous input and sharing of information from all professional team members. The respondents who were surveyed indicated a positive attitude towards developing their awareness and willingness to learn and apply green building principles. Knowledge of green star rating requirements for commercial developments in South Africa as well as general green building principles, allow professional team members to gain a competitive edge over more traditional practitioners in the building sector. In addition, professional members who are aware and alert to green building are at a better position to successfully implement a green building design, consequently minimising the negative impact buildings have on the environment and ensure sustainability.
56

Development of a multi-criteria approach for the selection of sustainable materials for building projects

Akadiri, Oluwole Peter January 2011 (has links)
Construction activity is known to have a major impact on the environment and is a major consumer of a wide range of naturally occurring and synthesized resources. Despite the recognition that environmental issues are important to the survival of the construction industry, the industry continues to degrade the environment, exploiting resources and generating waste, and is slow to change its conventional practices to incorporate environmental matters as part of its decision making process. With increased awareness and knowledge of these impacts, efforts are being made to avoid these adverse effects and to work towards impact mitigation. Among these is sustainable building material selection. Building material selection is an important issue in building design and construction decision-making and environmental issues need to be incorporated into the evaluation process. The research reported in this thesis was initiated to address these issues in the UK, towards developing an assessment model for incorporating sustainability into building material selection process. A questionnaire survey was conducted to investigate the level of awareness, knowledge and implementation of sustainable practices among architects and designers and how this impacts on their design decisions. To facilitate the implementation of sustainable practices into building material selection, a set of sustainable assessment criteria (SAC) for modeling and evaluating sustainability performance of building materials was developed. Building material can be assessed using an index system that combines the principal criteria of sustainable development. The derived criteria were assessed and aggregated into a composite sustainability index using the Analytical Hierarchy Process (AHP) technique which has been praised for its ability to incorporate both objective and subjective considerations in the decision process. The development of a sustainability index is a way of supporting decision makers faced with making numerous and sometimes conflicting evaluation as with building material selection. The methodology adopted in undertaking this research was the mixed method approach involving a detailed review of the relevant literature, followed by an industry-wide survey of UK architects and designers. Following this, case study was conducted to collect data for sustainability criteria used in the assessment model. The data collected were analyzed, with the aid of SPSS, Excel and expert choice software using a variety of statistical methods including descriptive statistics analysis, relative index analysis, Kendall’s concordance and factor analysis. The key finding was the existing gap between awareness and implementation of sustainable construction practices, which has led to failure of realizing the benefits of a sustainable approach to construction. The study showed a discrepancy between what architects and designers claim to be convinced about, and knowledgeable in, and their commitment and practices; they seem to be unable to translate their environmental awareness and knowledge into appropriate design decisions and are in need of a decision support system that can aid the incorporation of sustainability into building design. The model developed satisfy this gap and was validated by application to a roof covering material selection decision process for a case study building project by means of experts’ review via a survey and the findings obtained suggest that the model is valuable and suitable for use in practice. Finally, areas for further research were identified.
57

Práticas recomendadas para a gestão mais sustentável de canteiros de obras. / Recommendable practices for more sustainable siteworks management.

Araújo, Viviane Miranda 20 August 2009 (has links)
A construção sustentável é uma condição essencial para o alcance do desenvolvimento sustentável da sociedade. Para isso, é necessário preocupar-se com a sustentabilidade de todas as etapas do ciclo de vida de um empreendimento, desde sua concepção, passando pelo projeto, construção, manutenção, até sua demolição, considerando sempre as três dimensões da sustentabilidade: econômica, social e ambiental. Portanto, destaca-se o estudo da redução dos impactos negativos da etapa de construção de empreendimentos na medida em que a indústria da construção civil, além de grande consumidora de recursos naturais, é fonte de diversos impactos negativos causados ao meio ambiente. Dessa forma, o objetivo desta pesquisa é propor práticas a serem adotadas por empreendedores e empresas construtoras e seus subcontratados em seus canteiros de obras, visando a um processo de produção de edifícios mais sustentável em áreas urbanas. Essas práticas envolvem diretrizes tecnológicas e gerenciais, além de um guia, que propõe uma estratégia para implantação de canteiros de obras mais sustentáveis. A pesquisa, de propósito exploratório e caráter qualitativo, foi desenvolvida por meio de estudos teóricos, envolvendo revisão bibliográfica nacional e internacional, assim como observações em campo. Como principais resultados, apresentam-se: a evolução da matriz de correlação de aspectos e impactos ambientais de canteiros de obras de edifícios; a formulação de conjunto de diretrizes tecnológicas e gerenciais que visem a um processo de produção mais sustentável em canteiros de obras; e a elaboração de um guia para implantação de um canteiro de obras mais sustentável. / Sustainable construction is an essential condition for society sustainable development achievement. So, concerning about sustainability is indispensable for all stages of the building life cycle, since its conception, through design, construction, maintenance, until its demolition, considering the three dimensions of sustainability: economical, social and environmental. Hence, the building construction negative impacts reduction study stands out, as the construction industry, besides being a great consumer of natural resources, causes unwanted environmental impacts. Thus, the purpose of the research is to provide recommendable practices to be adopted by the constructors in their site works, aiming at a more sustainable production process in urban areas. These practices involve technological and managerial guidelines, besides a guide, which proposes a more sustainable site works establishment strategy. The research has exploratory object and qualitative nature, and was developed through theoretical studies, involving national and international literature review, and field observations. As main results there are: the evolution of the site works environmental aspects and impacts correlation matrix, the formulation of technological and managerial guidelines aiming at a more sustainable site works production process, and the preparation of a guide for a more sustainable site works establishment.
58

Gestão sustentável para área contaminada em campus universitário / Sustainable management of a contaminated area on campus

Bueno, Fernanda Bertaco 12 June 2017 (has links)
A presença de contaminação por substâncias perigosas no solo e na água subterrânea acarreta inúmeros problemas, tais como: risco à saúde humana e aos ecossistemas; comprometimento da água para abastecimento público; e redução do valor econômico e da função social do terreno. Embora as tecnologias de remediação sejam aplicadas para resolver problemas ambientais e de saúde pública, estas também podem gerar externalidades ambientais negativas como consumo de energia e recursos naturais; desequilíbrio do ciclo da água; erosão do solo; e emissão de gases de efeito estufa. Tendo em vista a recente ocorrência com áreas contaminadas na Universidade de São Paulo (USP) o presente trabalho visou elaborar um plano de gestão sustentável para uma dessas áreas localizada no campus USP da Capital, contribuindo com o Programa de Políticas Ambientais, sob coordenação da Superintendência de Gestão Ambiental da USP. A metodologia de pesquisa foi baseada em revisão bibliográfica sobre remediação sustentável e construção sustentável e em a análise qualitativa das ações, práticas e lições aprendidas de casos bem sucedidos de gestão das áreas contaminadas com elementos sustentáveis como subsídio para elaboração do plano. A partir da caracterização de quatro áreas contaminadas existentes no campus USP da Capital, foi selecionada a área da USP Leste para estudo de caso para promover o uso de práticas sustentáveis em campus universitário, de tal forma que proteja a saúde humana e minimize os impactos ambientais adversos. Com o intuito de buscar melhorias à gestão do campus, por meio da inserção da sustentabilidade na gestão da contaminação da USP Leste, a elaboração do plano de gestão sustentável considerou as especificidades locais nas práticas sustentáveis a serem implementadas, conforme as necessidades e diretrizes da USP. As soluções propostas incluíram a combinação do planejamento das fases de investigação e remediação com o design da construção de edifícios, que possam trazer benefícios ambientais, econômicos e sociais a todas as partes interessadas, tais como redução de custos a longo prazo relacionados à redução do consumo de energia e eletricidade pela implantação de sistemas de energia renováveis para fornecimento de energia elétrica ao sistemas de ventilação de metano / The presence of contamination by hazardous substances in soil and groundwater causes numerous problems, such as risk to human health and ecosystems; water impairment as drinking water; and reduced economic value and social function of the land. Although remediation technologies solve environmental and public health issues, they can also generate negative environmental externalities such as energy and natural resources consumption; imbalance of water cycle; soil erosion; and greenhouse gas emissions. Due to recent occurrence with contaminated areas at the University of São Paulo (USP) the present work aims to develop a sustainable management plan for one of these areas located on the USP Capital campus, contributing to Program of Environmental Policies, coordinated by the Superintendence of Environmental Management of USP. The research methodology was based on literature review about sustainable remediation and construction; and qualitative analysis of actions, practices and lessons learned applied on successful case studies of contaminated sites management with sustainable elements as subsidy for elaboration of the plan. Based upon a characterization of four contaminated areas located on USP Capital campus, the site of USP Leste was selected as case study in order to promote the use of sustainable practices on campus, through an approach that protects human health and minimizes adverse environmental impacts. In order to seek improvements to the campus management by sustainability integration in contamination management of USP Leste, the elaboration of sustainable management plan considered local specificities on sustainable practices to be implemented, according to the needs and guidelines of USP. The proposed solutions included the planning of investigation and remediation stages with the construction design of buildings that can bring environmental, economic and social benefits to all stakeholders, such as long-term cost savings related to the reduction of energy consumption and electricity by the implementation of renewable energy systems to supply electricity to methane ventilation systems
59

Durability of a recycled aggregate concrete base course material under coupled environmental exposure and cyclic

Unknown Date (has links)
Long term durability is a major concern for wide-scale use of recycled aggregate materials in civil engineering construction. The purpose of this study is to provide an insight into the damaging effects of combined wet-dry cycles and repeated mechanical loading in a recycled aggregate concrete (RAC) base course material made from recycled crushed concrete aggregate and cement. A coordinated experimental program followed by a mechanistic pavement modeling and life cycle analysis was conducted as part of this research study. This laboratory investigation was divided into three phases each consisting of both wet-dry exposed specimens (WD), and control or non wet-dry exposed specimens (NWD). Phase I experiments involved monotonic loading tests under compression and flexure to evaluate the strength properties. Phase II involved testing a total of 108 cylindrical specimens in cyclic compressive loading at three different stress ratios. After each regime of cyclic loading, residual compressive strengths were determined. In addition, the load-deformation hysteresis loops and the accumulated plastic deformation were continuously monitored through all loading cycles. Phase III included a flexural fatigue test program on 39 beam specimens, and fracture testing program on 6 notched beam specimens, each one having 19-mm initial notch. Traditional SR-N curves, relating the Stress Ratio (SR) with the number of cycles to failure (N or Nf), were developed. Fatigue crack growth rate and changes in Stress Intensity Factors were obtained to determine Paris Law constants and fracture toughness. A mechanistic analysis of a typical highway pavement incorporating RAC base was performed with KENPAVE program, followed by a Life Cycle Analysis (LCA) using the GaBi software. It was found that the specimens subjected to wet-dry cycles suffered significantly higher damage expressed in terms of accumulated plastic deformation, and loss of residual compressive strength, modulus, fatigue endurance limit, and design life, compared to specimens not exposed to wet-dry cycles. Although such degradation in material properties are important considerations in pavement design, a concurrent Life Cycle Analysis demonstrated that recycled aggregate concrete base course still holds promise as an alternative construction material from environmental stand point. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
60

ILUMINAÇÃO SUSTENTÁVEL: OS BENEFÍCIOS DO USO DA TECNOLOGIA LED NOS PROJETOS DE ILUMINAÇÃO.

Faria, Ana Carolina de 10 December 2014 (has links)
Made available in DSpace on 2016-08-10T10:44:48Z (GMT). No. of bitstreams: 1 ANA CAROLINA DE FARIA.pdf: 3678742 bytes, checksum: 140dc6483cae0309eb8ac3a1056ce995 (MD5) Previous issue date: 2014-12-10 / Artificial lighting is essential to modern living and presents a major challenge for the twenty-first century. Many problems associated with it have become major global concerns, not only because of the scarcity of natural resources it requires, but also because of the extent of the negative consequences arising from the segment. By means of an exploratory, participatory research, and a theoretical and documentary review, with emphasis on sustainable principles, it was seen that the problems caused by artificial lighting, in addition to energy consumption, also include people s health and well-being, changes in the natural cycle of animals, plants and insects, emission of greenhouse gases, pollution and contamination of the air, water and soil. Light Emitting Diodes (LED) has been presented to the market as an efficient and sustainable product to replace the different existing lamps, while promising to revolutionize lighting in general. This study set out to explore certain aspects involving the sphere of artificial lighting, to identify problems, point to solutions and analyze why LED is the most appropriate resource available today. The survey records the many benefits of LED as a solution to the different problems identified. It is a promising, commercially available technology which is likely to be a serious alternative to conventional technologies and will increase the energy efficiency of lighting systems. LED makes a major contribution to the artificial lighting sphere, but is not sufficient to make the segment sustainable. To become sustainable, social, economic, political and environmental aspects must be addressed. / A iluminação artificial é imprescindível na vida do homem moderno e tem sido um grande desafio para o século XXI. Diversos problemas já foram identificados, o que tem sido uma grande preocupação mundial, não apenas pela escassez dos recursos naturais utilizados para produzi-la, mas pela dimensão de consequências negativas provenientes do setor. Através da pesquisa exploratória, participativa, revisão teórica e documental, com ênfase nos princípios sustentáveis, identificou-se que os problemas causados pela iluminação artificial além do consumo de energia, incluem a saúde e o bem-estar do homem, alteração do ciclo natural de animais, plantas e insetos, emissão de gases de efeito-estufa, poluição e contaminação do ar, água e solo entre outros. Os Diodos Emissores de Luz (LED) tem sido apresentados no mercado como um produto eficiente e sustentável, para substituição das diversas lâmpadas existentes, prometendo revolucionar a iluminação de modo geral. O estudo teve como objetivo explorar alguns aspectos que envolvem o âmbito da iluminação artificial, identificar os problemas, apontar algumas soluções e investigar por que o LED é o mais indicado recurso disponível na atualidade. A pesquisa registra os diversos benefícios do LED enquanto solução para os diversos problemas apontados. É a tecnologia promissora que está disponível no mercado e provavelmente será uma importante alternativa para substituir as tecnologias convencionais e aumentar a eficiência energética dos sistemas de iluminação. O LED é um fator de grande contribuição para o âmbito da iluminação artificial, porém não é suficiente para que o setor se torne sustentável. Para chegar a resultados positivos que visam à sustentabilidade do segmento, os aspectos sociais, econômicos, políticos e ambientais devem ser inseridos neste contexto.

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