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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.
1

Optimizing haul routes using geospatial technologies for the delivery of ready-mix concrete in urban areas

Rao, Pradeep Suryanarayana Barimar, Zech, Wesley C. January 2007 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (p.116-119).
2

Optimizing haul routes using geospatial technologies for the delivery of ready-mix concrete in urban areas

Rao, Pradeep Suryanarayana Barimar, Zech, Wesley C. January 2007 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (p.116-119).
3

Optimizing haul routes using geospatial technologies for the delivery of ready-mix concrete in urban areas

Rao, Pradeep Suryanarayana Barimar, Zech, Wesley C. January 2007 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (p.116-119).
4

A new formal and analytical process to product modeling (PPM) method and its application to the precast concrete industry

Lee, Ghang. January 2004 (has links) (PDF)
Thesis (Ph. D.)--Architecture, Georgia Institute of Technology, 2005. / Eastman, Charles M., Committee Chair ; Augenbroe, Godfried, Committee Co-Chair ; Navathe, Shamkant B., Committee Co-Chair ; Hardwick, Martin, Committee Member ; Sacks, Rafael, Committee Member. Vita. Includes bibliographical references.
5

Marketing strategies of the Hong Kong ready-mix concrete suppliers.

January 1987 (has links)
by Chan Man Cheong Andrew. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1987. / Bibliography: leaf 78.
6

Product stewardship as a novel sustainability pathway for the UK precast concrete industry

Aliyu, Abdullahi A. January 2014 (has links)
Over the last two decades, sustainability has matured to become a societal imperative and is at the forefront of UK government policy and industry strategy. For example, the Strategy for Sustainable Construction (BERR, 2008) and Low Carbon Construction (BIS, 2012) reports have focused on encouraging more sustainable construction through reductions in energy, water and resource use. In response to such demands, the UK precast concrete industry developed a sector sustainability strategy and subsequently chose to continue activities in this area through an Engineering Doctorate (EngD) research project. The project focused on the scope for applying the principles of product stewardship (PS) as a means to mitigate environmental impacts associated with precast products, throughout the entire life-cycle of their use. Numerous PS schemes have been adopted in other industrial sectors, such as chemicals, electronics and product manufacture. One of the distinguishing features of PS is that multiple stakeholders need to take responsibility for their ‘share' of environmental impacts, and that life-cycle thinking should pervade the value chain. Hence, through PS, the precast industry might be able to address not only the impacts within cradle-to-gate phases, but also develop a framework to positively act on broader, cradle-to-grave impacts. The aim of this research was to develop a framework for embedding the principles of PS more deeply into the precast industry, creating a novel pathway towards more sustainable construction. The research commenced with a literature review to understand the key sustainability issues affecting the industry, followed by an analysis and synthesis of industry key performance indicator (KPI) data from 2006–2012. Industry participation in the research was facilitated through a questionnaire survey and interviews with senior staff within UK precast businesses. Evidence of PS practices was found to exist within the industry through responsible sourcing schemes, implementation of Environmental Management Systems and through the mitigation of various specific impacts. However, the coordinated communication of such initiatives was found to be lacking and with the advent of new European standards around Environmental Product Declarations (EPD) for construction, it was decided that the precast industry would benefit from a sector-specific EPD framework to capture and communicate its PS credentials. An EPD framework and tool was therefore developed and validated through a focus group, to establish whether an EPD can be used successfully to deliver environmental information and refine an approach such that it would accord with the principles of PS. Further research and development arising from this research could focus on implementation and evaluation of the industry-specific EPD scheme, a mechanism to communicate and share life-cycle information amongst upstream and downstream stakeholders and a means through which stakeholder responsibility can be attributed and managed effectively. The key findings of this research have been presented in four peer–reviewed papers (one of which is in draft) which are presented in the Appendices.
7

Promoting Circular Economy By Partial Replacement Of Cement With SCMs : A Review On Wood Ash / Främja cirkulär ekonomi i betongindustrin i Sverige genom att delvis ersätta cement med alternativa bindemedel : En översikt av träaska

Salman, Asal January 2022 (has links)
The European Commission adopted the first action plan for the transition to a circular economy in 2015. As a result, the concrete industry’s goal is for all concrete produced in Sweden to be climate neutral by 2045. Cement production is the third-largest carbon dioxide emitter in Sweden and accounts for 90% of concrete’s carbon dioxide emissions. Thus, to lower the climate footprint of concrete, it is necessary to find alternatives to cement. The potential of the use of wood ash in cement as a supplementary cementitious material (SCM) has been investigated in several studies. Due to Sweden's nature and wood industry, a comprehensive study has been done to investigate the possibility of using wood ash as an SCM in Sweden based on availability and efficiency. This work aims to investigate the obstacles and driving forces that concrete producers face when transitioning to a circular economy by partially replacing cement with new potential SCMs. The aim is also to investigate the availability of wood ash generated in Sweden and account for the potential to be used as an SCM. Qualitative semi-structured interviews with open-ended questions were conducted to determine the obstacles and drivers that concrete producers in Sweden face when converting to a circular economy by partially replacing cement with new potential SCMs. The amount of ash produced in Sweden was estimated based on the value of ash content and the potential annual supply of wood fuels in Sweden. In addition, a literature review was performed to investigate the properties of wood ash. The economic and environmental aspects, as well as the fact that the supply of fly ash and slag is likely to decrease in the future form the main driving forces for concrete producers. The obstacles raised by the correspondents were the availability of SCMs, technical barriers, logistics, and standards. The amount of the annual production of wood ash in Sweden is estimated to be between 851 450 and 1 232 950 tons. The chemical characteristics of wood ash did not meet the requirements according to European standard (EN450-1). However, the reviewed articles indicated a potential for wood ash to be used as a supplementary cementitious material due to the indication of some hydraulic and pozzolanic activities. The combination of fly ash and wood ash in concrete is considered viable due to promising results based on mechanical strength. / EU-kommissionen antog den första handlingsplanen för omställningen till en cirkulär ekonomi 2015. Som ett resultat av detta är betongindustrins mål att all betong som används i Sverige ska vara klimatneutral år 2045. Cementindustrin är den tredje största koldioxidutsläpparen i Sverige och står för 90 % av betongens koldioxidutsläpp. För att sänka betongens klimatavtryck är det nödvändigt att hitta alternativ till cement. Potentialen för användningen av träaska i cement som ett alternativt bindemedel har undersökts i flera studier. Med hänsyn till Sveriges natur- och träindustri har en omfattande studie gjorts för att undersöka möjligheten att använda träaska som alternativ bindemedel i Sverige utifrån tillgänglighet och effektivitet. Arbetet syftar till att undersöka de hinder och drivkrafter som betongföretag möter vidövergången till en cirkulär ekonomi genom att delvis ersätta cement med nya alternativa bindemedel. Syftet är också att undersöka tillgången på träaska som genereras i Sverige och redogöra för potentialen att användas som ett bindemedel. Kvalitativa semistrukturerade intervjuer med öppna frågor genomfördes för att fastställa de hinder och drivkrafter som företag inom betongtillverkning i Sverige möter vid en omställning där cement ersätts delvis med nya bindemedel. Mängden aska som produceras i Sverige har uppskattats utifrån värden på askhalt och den potentiella årliga tillgången på trädbränslen i Sverige. Dessutom har en litteraturöversikt genomförts för att undersöka träaskans egenskaper. Drivkrafterna för en omställning till cirkulär ekonomi hos betongindustrier genom delvis ersättning av cement med nya alternativa bindemedel är de ekonomiska och miljömässiga aspekterna samt det faktum att tillgången på flygaska och slagg riskerar att sjunka i framtiden. Hindren som korrespondenterna tog upp var tillgången till alternativa bindemedel, tekniska barriärer, logistik och standarder. Mängden av den årliga produktionen av träaska i Sverige uppskattas mellan 851 450 och 1 232 950 ton. Kemiska egenskaper hos de undersökta träaskorna uppfyller inte kraven enligt europeisk standard (EN450-1). Litteraturöversikten visar dock en potential för träaska att användas som ett alternativt bindemedel till följd av en viss hydraulisk och puzzolanisk aktivitet. Kombinationen av flygaska och träaska i betong anses lönsam på grund av lovande resultat baserade på mekanisk hållfasthet.
8

Reuse and recycling of concrete : Economic barriers and possible opportunities for future profitability / Återbruk och återvinning av betong : Ekonomiska hinder och möjligheter för framtida lönsamhet

Knutsson, Julia January 2023 (has links)
Today, the world's natural ecosystems are threatened by increased extraction of raw materials andgreenhouse gas emissions to the atmosphere. One of the drivers of this problem is the impact fromindustries through their production. A possible strategy to reduce pressure on natural ecosystems is toincrease the use of industrial ecosystems. The circular economy is an approach that supports the reuseof products by reusing, recycling and minimising waste. Like a natural ecosystem, waste can beused as an input material for new production. Today, the construction industry contributes to a largeamount of waste, requires a large amount of extracted materials and generates high levels ofgreenhouse gas emissions. One of the world's most widely used construction materials is concrete. Byreusing and recycling concrete, the need for virgin material and waste sent to landfill can be reduced. The aim of the study is to contribute to a better understanding of the current economic barriers andhow different activities could be improved to create economic profitability and stimulate the reuse andrecycling of concrete. Through a literature study of previous research regarding economic barriers ofreuse and recycling of building materials, different circular strategies for the management of concrete,and EU and Swedish legislation, regulations, and certifications for circular economy in theconstruction industry, relevant interview questions could be developed. The interviews represent theresult and answer questions regarding current economic barriers for reuse and recycling of concreteand opportunities for future profitability, as well as exploring the environmental suitability ofdifferent circular strategies in the concrete industry. A total of 10 interviews were conducted withdifferent stakeholders in the concrete and construction industry. The main economic barriers identified in the study regarding reuse of concrete are due to lack ofmarket interest, difficult logistics involving transport and storage of elements, getting an economicflow in the business model, increased labour and quality certification. The most essential economicbarriers to the recycling of concrete are due to a potential risk for the material to be classified as waste,increased transport of materials, planning of material supply, higher cost of recycled materialcompared to virgin material, and regulations that promote high-value reuse. Identified opportunitiesthat can contribute to improved future profitability for both reuse and recycling of concrete arecircular strategies and business models, the ability to demonstrate reduced climate impact,regulations and standards, and new work methods. The interviews have also indicated that different circular strategies for the management of concreteare suitable in different types of projects. The upcycling of materials should not be favoured at anycost if it can be proven that the method of recycling contributes to the need for less virgin material.Circular strategies in the concrete industry should beneficially be included in a CE at the societal level.In this way, synergies can be created, and the use of resources can benefit both the environment andthe economy. / Idag hotas världens ekosystem genom allt fler uttag av naturens egna råvaror och ökadeväxthusgasutsläpp till atmosfären. Industrier har stor påverkan på detta problem. En möjlig strategiför att minska påfrestningar på naturliga ekosystem är att i högre utsträckning utnyttja industriellaekosystem. Cirkulär ekonomi är en metod som stödjer återanvändning av produkter genom attåterbruka, återvinna och minimera mängden avfall. Likt ett industriellt ekosystem kan avfall användassom ingående material vid nyproduktion. Idag bidrar byggindustrin till en stor mängd avfall, kräveren stor mängd utvunnet material och genererar höga växthusgasutsläpp. Ett av världens mestanvända byggmaterial är betong. Genom att återbruka och återvinna betong kan behovet avjungfruligt material och avfall som behöver deponeras minskas. Syftet med studien är att bidra till en bättre förståelse av nuvarande ekonomiska hinder och hur olikaaktiviteter kan förbättras för att skapa ekonomisk lönsamhet och stimulera återbruk och återvinningav betong. Genom en litteraturstudie bestående av tidigare forskning av ekonomiska hinder medåterbruk och återvinning av byggmaterial, olika cirkulära strategier för hantering av betong, samt EUoch svenska lagar, regleringar och certifieringar för cirkulär ekonomi i byggbranschen kunde lämpligaintervjufrågor tas fram. Intervjuerna ligger till grund för resultatet och besvarar frågor vad gällerdagens ekonomiska hinder för återbruk och återvinning av betong och möjligheter för framtidalönsamhet, samt utforskandet av lämplighet för olika cirkulära strategier i betongindustrin. Totaltgenomfördes 10 intervjuer med olika aktörer inom betong- och byggindustrin. De främsta ekonomiska hinder som identifierats i studien vad gäller återbruk av betong beror påavsaknad efterfrågan, försvårad logistik som innebär transportering och förvaring av element, att fåett ekonomiskt flöde i affärsmodellen, ökade arbetsmoment och kvalitetssäkring. De mest väsentligaekonomiska hinder vad gäller återvinning av betong beror på risken att materialet kan klassas somavfall, ökad mängd transporter av material, planering av materialåtgång, den högre kostnaden föråtervunnet material jämfört med jungfruligt material och regleringar som förespråkar återanvändningav högt värde. Identifierade möjligheter som kan bidra till förbättrad framtida lönsamhet för bådeåterbruk och återvinning av betong är cirkulära strategier och affärsmodeller, möjligheten att påvisaminskad klimatpåverkning, regler och standarder samt nya arbetsmetoder. Utifrån intervjuerna har det även framkommit att olika cirkulära strategier för hantering av betong ärlämpliga vid olika projekt. Att upcycla materialet bör inte till varje pris eftersträvas om det kan bevisasatt metoden för återvinningen kan bidra till ett behov av en lägre mängd jungfruligt material.Cirkulära strategier inom betongindustrin bör fördelaktigt inkluderas i en CE på samhällsnivå. Då kansynergier skapas och användning av resurser kan främja både miljö och ekonomi.
9

Safety risk assessment and improvement method for precast/ prestressed concrete industry plant

Joshi, Sayali G. 30 April 2021 (has links)
The Precast/Prestressed Concrete Institute (PCI) is the technical institute for precast/prestressed concrete industry. The plant involves activities such as placing high tensile steel strings inside the concrete products before they harden. This process needs the strings to be "stressed" hydraulically with high tension, which provides possibility of breaking the strand. Hence, employees may face a severe injury around the stressing bed. As various activities take place on the plant at the same time, employees must follow certain safety protocols while being around the plant. Another safety concern on the precast plant is silica exposure. Occupational Safety and Health Administration (OSHA) has provided various guidelines and tools to minimize silica exposure. Employees need to be careful and follow these safety protocols, otherwise it may lead to severe lung disease. Thus, employees need the appropriate safety training which will motivate them to follow safety protocols rigorously. The Bayesian Network (BN) methodology helps analyze plant structure to understand potential risk factors and causes that can be fixed by the employer paying more attention. The current traditional training methods such as videos, PowerPoint slides, or on-paper training, are not as effective in conveying the severity of the risky situations. This research focuses on precast plant activities while trying to identify the factors affecting plant safety. The current results suggest that using the BN study for the factors, such as stressing, chipping, leg injuries, tripping, and suspended loads, that may cause accidents or affect plant safety have a major impact on overall plant safety. Further sections of the dissertation discuss Fault Tree Analysis for risk assessment. It is observed that the BN study outperforms the risk assessment. Improvisation in safety protocols associated with these factors will help mitigate overall plant risks. In addition, study includes the development of immersive training methods and comparison of the immersive method to current safety training methods. Virtual Reality (VR) training module provides significant evidence to improvement in motivation level compared to traditional training. Knowledge gain concerning the safety protocols proves to be increasing for employees after the VR training method compared to the traditional training methods.

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