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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.
71

Shear capacity of beams of reinforced high performance concrete

Gabrielsson, Henrik January 1993 (has links)
No description available.
72

Mognadsutveckling i ung betong : temperaturkänslighet, hållfasthet och värmeutveckling

Ekerfors, Katarina January 1995 (has links)
<p>Godkänd; 1995; 20080330 (ysko)</p>
73

Product models for concrete structures : standards, applications and implementations

Rönneblad, Anders January 2003 (has links)
The product model approach for the construction industry is fairly new subject field, especially the implementation of the result in the building process. The aim of the research and the contribution to the goal of better utilize processes is shortly described below. Limited to concrete building constructions, including both in-situ (cast in place) and precast (prefab) structures. Focus on product data models and us of product models. Standardized as well as own developed product data models are included. Consist of studied and evaluation of international standards, the applicable to the construction industry and the possibilities to develop implementations. Developing of effective workprocesses for structural designers is essential. This even includes relations to the production phase. Use commercial software system for demonstrations purposes, by implement new technology in StruSoft existing product assortment. The implementation prototypes give the opportunity to demonstrate the result to the construction industry and to promote a useful debate about working methods. The long-term goal is to give the actors in the structural design process, tools for sharing information and more efficient design methods. This research project includes four sub projects, all with different scope, main goals but the target groups are the same, namely structural designer, the concrete industry and software developer in this domain. / Godkänd; 2003; 20070217 (ysko)
74

Numerical modelling of floating ice covers including anisotropy and inhomogeneity

Nyström, Mikael January 1992 (has links)
<p>Godkänd; 1992; 20080407 (ysko)</p>
75

Effektivare samverkansbroar : prefabricerade farbanor med torra fogar

Stoltz, Anders January 2001 (has links)
Dagens vägbroar utgörs ofta av samverkanskonstruktioner med bärande huvudbalkar av stål och farbana av betong. Detta sätt att bygga har visat sig vara kostnadseffektivt. På senare tid har det blivit allt viktigare att byggtiden dessutom skall minimeras så långt som möjligt för att på detta sätt minska investeringskostnaden. Dessutom ställs det krav på hög kvalitet och säkerhet. Uppsatsen presenterar en metod som gör det möjligt att uppfylla dessa krav vid byggande av samverkansbroar. Metoden baseras på ett system som har hög prefabriceringsgrad. Förutom stålbalkarna så är även betongfarbanan prefabricerad. Det unika med metoden som beskrivs i denna licentiatuppsats är att fogarna mellan elementen är torra. I stället för att ha en kontinuerlig skarv med genomgående armering så används överlappande betongklackar för att föra över vertikal krafterna mellan elementen som uppstår då ett fordon passerar fogen. Metoden är provad på ett verkligt objekt, en enspanns bro med tryckta fogar. För detta fall föreligger det inte några stora hinder eftersom fogen aldrig kan öppna sig. Om bron däremot utförs som en flerspannsbro kan det uppstå problem över ett innerstöd eftersom fogen då blir dragen och därmed vill öppna sig. För att undersöka hur den beter sig under sådan belastning har det utförts försök vid Testlab vid LTU. Syftet var att undersöka hur mycket fogen öppnar sig i vertikal såväl som horisontell riktning vilket har betydelse för isoleringsskiktet och beläggningen. En annan del av försöket bestod i att undersöka om de skjuvförbindande svetsbultarna skulle utmattas då bron böjer sig över innerstödet till följd av passerande fordon. För att underlätta utvärderingen skapades också en FE-modell där det var möjligt att variera storleken på elementen och se hur detta påverkade resultaten. Ett av syftena med denna modellering var att undersöka hur stor betongbredd som medverkande vid olika förhållanden mellan längd och bredd på elementen. Det har också utförts fältmätningar på den verkliga bron för att se hur stor samverkan som fanns mellan stålet och betongen. Även dessa undersökningar FE modellerades för att underlätta utvärderingen. Dessutom har ett examensarbete löpt under projektets utförande som tittade på de samhällsekonomiska effekterna för detta koncept jämfört med andra mer traditionella metoder. Även effekter som trafikantstörningar vägdes in för att få en så allomfattande jämförelse som möjligt. En litteraturfördjupning har också utförts för att ge en uppfattning om vad som är gjorts runt om i världen på liknade koncept och lite grann om vilken forskning som har utförts av andra. / <p>Godkänd; 2001; 20070313 (ysko)</p>
76

Finite element simulation of flow in granular materials

Karlsson, Tomas January 1996 (has links)
<p>Godkänd; 1996; 20080417 (ysko)</p>
77

Localization modelling with inner softening band finite elements

Tano, Robert January 1997 (has links)
<p>Godkänd; 1997; 20070418 (ysko)</p>
78

Assessing the economic value of using structural health monitoring systems on South African bridges by studying the Ermelo-Richards Bay Freight Railway line

Mmekwa, Keamogetswe Antoinette January 2017 (has links)
There is a need for appropriate tools and techniques to undertake the vast task of sound repair, maintenance and rehabilitation of concrete infrastructure which is deemed to be deteriorating at unacceptable rates. Low economic growth predictions lead to limited budgets and a deferring of maintenance. The use of technology could be used to extend the useful life of concrete structures. Structural Health Monitoring Systems (SHMS) can be used to monitor structural integrity and the information obtained from these systems can be used in detecting overloading (on bridges for instance) and to alert asset managers of any due maintenance. Büyüköztürk (2007) argues that conventional methods of inspecting the condition of bridges are generally subjective and that this does not give a true reflection of the state of the structure. The objective of this study is to determine the economic value of using SHMS on South African bridges as opposed to conventional bridge inspection methods. The detailed study was conducted on railway bridges on the Transnet Freight Rail (TFR) Ermelo - Richards Bay coal route to assess the contribution that a commodities line such as this one makes to the South African economy. This study makes use of data from Transnet to establish economic value. It is recommended that the results and recommendations be used for a more detailed study into the value of SHMS to be extrapolated for use on other bridges (e.g. road bridges).
79

An exploration of the parameters of liveable urbanism through inclusive incremental development

Duke, David 05 March 2020 (has links)
“Despite a significant reduction in the percentage of population living in informal settlements from 2000 to 2014, the absolute number of people living in deplorable conditions has increased from 689 to 880 million people over the same period. Current policy and planning practice in developing countries has not been able to cope with such pervasive rapid urbanisation. By 2050 the United Nations predicts two-thirds of the global population will live in cities. Of which as many as one-third of this population could be living in informal settlements (slums). To address these unsustainable and undesirable trends in support of the disadvantaged and maintaining environmental sustainability, this minor dissertation conducts comprehensive research of contemporary policy and planning work to seek alternatives. The purpose of the literature review is to identify commonalities, differences, gaps of knowledge and constraints of current policies and planning practice currently used to plan and manage growth of cities. Analysis and findings then inform and add value in exploring parameters for a 'liveable’ or improved urbanism from that currently experienced in informal settlements. Historic global policies focusing on government led top down approaches to provide large scale low cost housing have not kept up with demand, although they remain popular politically. From these policy and planning failures, it is evident that a more inclusive and incremental approach better utilizing available human capital should be considered. Critical analysis of literature with an alternative urbanism and planning paradigm in mind emerges in the findings and conclusion in the form of recommended parameters for a new inclusive and incremental urbanism. Such urbanism is entirely possible provided the critical issues identified such as lack of political will and good governance can be mitigated. To dramatically improve the lives of millions will require a compelling vision and collaborative effort seldom seen in current policy and planning of developing countries. Despite the daunting task, this paper seeks to define a conceptual framework drawn from findings to mitigate issues and guide an alternative vision of the future. The alternative urbanism that emerges from the conceptual framework may fall somewhere between that of current informal settlements and current discourse such as smart cities’’
80

Exploring and profiling of childhood illnesses in informal settlements in relation to flooding: a case study of Barcelona, Cape Town South Africa

Machiridza, Rumbudzayi Dorothy January 2013 (has links)
Includes abstract. / Includes bibliographical references. / A significant number of studies have documented illnesses that follow flooding as a result of people coming into contact with contaminated water. Floods cause health risks by exposing children to bacteria, protozoa, viruses and fungi through contaminated water, contaminated household items, dead animals and mould, as a result of inhalation, ingestion and wound infections. This study focuses on the impacts of flooding on child health in the informal settlement of Barcelona, Cape Town. The health outcomes of flooding are conceptualized within the vulnerability framework of Turner and colleagues (2003), which explores human vulnerability in terms of exposure, sensitivity and resilience. In addition, the framework reflects global environment change and it powerfully defines the term vulnerability. There were three main research objectives. Firstly, the research established factors and other stressors that determined the occurrence of water-related illnesses among children in informal settlements as a result of flooding. Secondly, the research explored and identified the flood-related childhood illnesses. Lastly, the research identified strategies households applied in order to protect their children from flood-related illnesses. The study was conducted through the administration of 45 questionnaires, 2 focus group interviews and personal observation. The study adopted both qualitative and quantitative methodologies in order to understand the perceptions of what flood-related illnesses were and what caused them. Results from the qualitative research were used to triangulate data from the quantitative research. The integration of both methodologies provided additional solutions to understanding the impacts of floods on child health in Barcelona. Ethics approval was granted by Ethics Committee of the Engineering and the Built Environment Faculty at the University of Cape Town. The research findings suggest that flood-related illnesses in Barcelona were a result of different and interlinking factors. The various factors included poor access to basic services, general poor urban health, and location of the settlement and household hygienic factors. In addition, children were more exposed to risks inside dwellings as compared to risks outside dwellings. Vector-borne illnesses were the least recorded cases. In order to mitigate child illnesses resulting from flooding the households applied both proactive and reactive strategies such as buying of medication before and during flooding, bathing their children after they finish playing, and sending children to relatives during the flooding period and cleaning dwellings after flooding. Research findings highlighted that there is a significant association between child health and flooding in Barcelona. The types of illnesses that were reported were mainly water-related illnesses, which included respiratory illnesses, gastrointestinal illnesses, skin and ear infections and vector-borne illnesses.

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