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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.
871

Le principe de précaution en droit de l'Union européenne / The precautionary principle under european union law

Donati, Alessandra 09 July 2019 (has links)
Partant de la prémisse de la nature flexible et complexe du principe de précaution en droit européen, le but de cette étude a été d'en donner une interprétation polycentrique, fondée sur la diversité plutôt que sur l’uniformité. Pour atteindre un tel objectif, une méthode issue du pluralisme méthodologique a été employée. Celle-ci nous a permis de rechercher la uniras multiplex parmi les différentes définitions et applications de ce principe. La thèse ici soutenue a consisté à démontrer que l'interprétation polycentrique du principe de précaution peut être construite à partir de deux concepts : l'anticipation et l'action. Dans la première partie de cette étude, il a été montré comment le principe de précaution permet d'anticiper le temps de l'action publique au stade de l'incertitude scientifique. Nous avons à cet égard expliqué que l'anticipation suppose la qualification par le droit et l'évaluation par la science des risques incertains. La seconde partie de cette étude a été finalisée à démontrer comment, une fois le temps de l'action anticipé, les décideurs doivent agir sur le fondement du principe de précaution. Nous avons soutenu, à cet égard, que l'action sur la base de ce principe a une portée et des conséquences distinctes sur le plan procédural et substantiel. Les décideurs ont, en effet à la fois une obligation de prise en compte et une faculté de mise en œuvre du principe de précaution. / By acknowledging the flexible and complex nature of the precautionary principle in EU law, the purpose of this work is to provide a polycentric interpretation of this principle based on diversity rather than uniformity. To achieve this objective, a methodology derived from the methodological pluralism is employed. This allows for the “unitas multiplex” between the different definitions and applications of the precautionary principle to be researched. The core claim is that the polycentric interpretation of the precautionary principle can be built on two concepts: anticipation and action. In the first part of this study, I argue that anticipation implies the qualification by law and the evaluation by science of uncertain risks. In the second part, I consider that, after having anticipated the time of action, decision-makers should act on the basis of the precautionary principle. However, the action undertaken has different meanings and consequences from the procedural and substantive perspective. From the procedural side, the decision-makers have the obligation to take into account this principle, white they remain free on the substantive side, to adopt a precautionary measure.
872

ANALYTICAL METHODS TO QUANTIFY RISK OF HARM FOR ALERT-OVERRIDDEN HIGH-RISK INTRAVENOUS MEDICATION INFUSIONS

Wan-Ting Su (5930303) 16 January 2020 (has links)
<p>The medication errors associated with intravenous (IV) administration may cause severe patient harm. To address this issue, smart infusion pumps now include a built-in dose error reduction system (DERS) to help ensure the safety of IV administration in clinical settings. However, a drug limit alert triggered by DERS may be overridden by the practitioners which can potentially cause patient harm, especially for high-risk medications. Most analytical measures used to estimate the associated risk of harm are frequency-based and only consider the overall drug performance rather than the severity impact from individual alerts. Unlike these other measures, the IV medication harm index attempts to quantify risk of harm for individual alerts. However, it is not known how well these measures describe the risk associated with alert-overridden scenarios. The goal of this research was (1) to quantitatively measure the risk for simulated individual alert-overridden infusions, (2) to compare these assessments against the risk scores obtained among four different analytical methods, and (3) to propose better risk quantification methods with a higher correlation to risk benchmarks than traditional measures, such as the IV Harm index. </p> <p>In this study, 25 domain experts (20 pharmacists and 5 nurses) were recruited to assess the risk (adjusted for risk benchmarks) for representative scenarios created based on hospital alert data. Four analytical methods were applied to quantify risk for the scenarios: the linear mixed models (Method A), the IV harm index (Method B), Huang and Moh’s matrix-based ranking method matrix-based method (Method C), and the analytical hierarchy process method, adjusted by linear mixed models (Method D). Method A used seven alert factors (identified as key risk factors) to build models for risk prediction, and Methods B and C used two out of seven factors to obtain risk scores. Method D used pairwise comparison surveys to calculate the risk priorities. The quantified scores from the four methods were evaluated in comparison to the risk benchmarks.</p> <p>Risk assessment results from the domain experts indicated that overdosing scenarios with continuous and bolus dose field limit types had significantly higher risks than those of bolus dose rate type. About the soft limit type, the expected risk in the group with a large soft maximum limit was significantly higher than the group with a small soft maximum limit. This significant difference could be found in the adult intensive care unit (AICU), but not in adult medical/surgical care unit (AMSU). The comparisons between four analytical methods and risk benchmarks showed that the risk scores from Method A (<i>ρ</i> = 0.94) and Method D (<i>ρ </i>= 0.87) were highly correlated to the risk benchmarks. The risk scores derived from Method B and Method C did not have a positive correlation with the benchmarks.</p> <p>This study demonstrated that the traditional IV harm index should include more risk factors, along with their interaction effects, for increased correlation with risk benchmarks. Furthermore, the linear mixed models and the adjusted AHP method allow for better risk quantification methods where the quantified scores most correlated with the benchmarks. These methods can provide risk-based analytical support to evaluate alert overrides of four high-risk medications, propofol, morphine, insulin, and heparin in the settings of adult intensive care unit (AICU) and adult medical/surgical care unit (AMSU). We believe that healthcare systems can use these analytical methods to efficiently identify the riskiest medication-care unit combinations (e.g. propofol in AICU), and reduce medication error/harm associated with infusions to enhance patient safety.</p> <p> </p>
873

Preimplantation genetic diagnosis and therapy in humans- Opportunities and risks

Hedberg, Rickard January 2020 (has links)
IntroductionPreimplantation Genetic Diagnosis (PGD) was developed in the 1990s and has been used since to diagnose and discard embryos with genetic conditions or chromosomal abnormalities. CRISPR-Cas9 was discovered in 2012 and has been used in research, but has not become clinical practice on humans yet. CRISPR-Cas9 could potentially be applied to treat and prevent genetic disorders.AimThe aim was to investigate the ethical dilemmas of each method through a set of research questions. The ethics of applying PGD according to Swedish guidelines and applying CRISPR-Cas9 on humans was investigated.MethodologyThis was not a systematic literature review. Instead, articles have been selected based on their explanation of each method and uniqueness or volume of ethical arguments surrounding each method, that is of relevance for the discussed issues.ResultsArguments in favour of PGD addressed among other things the somatic and psychological health of future children and parents along with the economical benefits. Arguments against PGD addressed different dilemmas of discarding an embryo and thereby a future individual. Arguments against CRISPR-Cas9 addressed technical limitations, our limited knowledge of genetics and more. Arguments in favour addressed benefits in clinical medicine and research.ConclusionsPGD according to Swedish guidelines was found to be ethically acceptable, since its restrictive use that have not given room for ethically dubious applications. CRISPR-Cas9 was found not to be safe enough for human applications at this moment due to technical limitations. If these were to be solved, caution and restraint must be urged.
874

Dispositifs de gestion et risques psychosociaux : une étude qualitative des risques humains et de leur gestion dans les organisations / Management tools and psychosocial risks. A qualitative study of human risks and their management in organizations

Beau, Pauline 16 October 2017 (has links)
Depuis la fin des années 2000, les risques psychosociaux (stress, anxiété, burn-out…) sont au cœur des débats sociétaux. La littérature explique l’apparition accrue de ces phénomènes par la diffusion d'une culture du résultat exigeant toujours plus des individus et contrôlant leur performance grâce à un ensemble de dispositifs et d'outils de gestion. Parallèlement, pour prévenir les risques psychosociaux les organisations s'appuient également sur des outils de gestion. Cette thèse vise donc à répondre à la question de recherche suivante : dans quelle mesure les outils de gestion participent aux risques psychosociaux, à leur production et à leur prévention ? Pour y parvenir nous avons réalisé une étude exploratoire, puis, quatre études de cas au sein d’organisations privées et publiques selon un design qualitatif composé de 67 entretiens semi-directifs, de deux observations non participantes et de documentations internes et externes. En étudiant les relations systémiques entre perceptions du réel, individus et outils de gestion, nous approfondissons les mécanismes complexes liant culture du résultat, dispositifs de gestion et risques psychosociaux. / Since the late 2000s, psychosocial risks (job strain, anxiety, burn out…) are a debating point. The literature explains it by the dissemination of a results-oriented culture which demands more and more to people and controls their performance by using management tools. Furthermore, to prevent psychosocial risks organizations also use management tools. That's why we focus our attention on the use of management tools in organizations to study the complex links between management control and psychosocial risks. Thus, our thesis aim to answer the following research question: to what extent management tools participate to psychosocial risks, to their creation and to their prevention ? To do this, we have first made an exploratory study and then four case studies in private and public organizations. So our qualitative design is composed by collecting 67 semi-structured interviews, two non-participatory observations and internal and external documents. By studying mutual relationship between perceptions of reality, individuals and management tools, we explore the complex mechanisms binding results-oriented culture, management tools and psychosocial risks.
875

The relationship between supply chain risk, flexibility and performance in the South African public sector.

Mhelembe, K. 07 1900 (has links)
D. Tech (Department of Human Resource Management, Faculty of Management Sciences), Vaal University of Technology. / The expectation by South Africans is that the public sector must contribute positively to the economy. However, the general perception is that the public sector is failing to fulfil its mandate due to systemic problems in the entire public sector. Its supply chain in South Africa is both volatile and imperfect. This is demonstrated by the level of service delivery protests, which emanate from the feeling that the public is not receiving the quantity or quality service that they need. This study aimed to assess the relationship between supply chain risks, supply chain flexibility and supply chain performance in the South African public sector. A conceptual framework was developed, which included six supply chain risk factors, namely, government policies, supply complexity, availability of skills, supplier performance monitoring, information security and process efficiency, which feed into supply chain flexibility, which in turn leads to supply chain performance. Seven hypotheses underlying these relationships were put forward for testing. A quantitative approach using the cross-sectional survey design was adopted in which a questionnaire was distributed to 306 conveniently selected supply chain professionals who were based in Gauteng province. Items used in the survey questionnaire were adapted from previously validated scales. A confirmatory factor analysis was conducted to test the psychometric properties of the measurement instrument. Descriptive statistics were used to analyse the perceptions of respondents towards the factors under consideration in the study. Hypotheses were tested using the structural equation modelling approach. The results of the study show that the threat from supply chain risks in the South African public sector remains high, and that flexibility and performance of the supply chain remains unsatisfactory. Hypotheses tests showed that all six supply chain risks significantly predicted supply chain performance. While the other supply chain risks were positively related to supply chain flexibility, the relationship between the flexibility and supply complexity was negative. Amongst the supply chain risks considered in this study, availability of skills emerged as the strongest predictor of supply chain flexibility. The study further showed that supply chain flexibility significantly and positively predicts supply chain performance. Theoretically, the study provides a specific conceptualization of the relationship between supply chain risks, supply chain flexibility and supply chain performance within the South African public sector, where no such study has been conducted before. Practically, it provides information to supply chain professionals in the South African public sector regarding the improvement of supply chain performance. The study underscores that the performance public supply chain in South Africa can be improved by managing the six risks considered in this study, and their contribution to supply chain flexibility.
876

Analýza rizik spojených s užíváním doplňků stravy pacienty v preoperativním období / Analysis of the risks associated with using dietary supplements by patients in pre-operative period

Faltysová, Anna January 2018 (has links)
Charles University, Faculty of Pharmacy in Hradec Kralové Department of Social and Clinical Pharmacy Author Anna Faltysová Supervisor PharmDr. Jitka Pokladníková, Ph.D. Consultant PharmDr. Julie Zubrová Title of Diploma Thesis Analysis of the risks associated with using dietary supplements by patients in pre-operative period Objectives: The thesis deals with the problem of the dietary supplement use by patients in the time before surgery. The aim of the thesis is to evaluate the prevalence of dietary suplement use by patients before surgery. Another aim is to point to potential danger which could endanger the patient while irrational using of the dietary supplement before the medical interventions (interactions of dietary supplement, side effects of dietary supplement). Methodology: The questionnaire research was conducted in order to obtain the data. It was counducted between 9th May 2017 till 30th June 2018 at 9 departments of the University Hospital in Hradec Králové. In total 332 patients in the time before surgery were asked and 257 completed questionnaires were analysed. Results: From the results of the study we can see the prevalence of the dietary supplement use by the patients in the time before surgery, which amounts to 42 %. It was stated that most of the patients does not inform their...
877

Brandrisker i däckhotell : Är samhällets krav på byggnadstekniskt brandskydd tillräckligt?

Öhrling, Emil January 2021 (has links)
Syftet med studien är att undersöka de risker som finns i samband med brand i däckhotell, samt utvärdera om samhällets krav på byggnadstekniskt brandskydd är tillräckligt för att hantera risknivån. Samhällets krav i studien är Boverkets byggregler BFS 2011:6 med ändring till och med BFS 2020:4 (BBR) och den kravställning som sker i enlighet med förenklad dimensionering. Kraven i BBR har kvantifierats för att möjliggöra en jämförelse mellan BBR och de verkliga förutsättningar som återfinns på däckhotell. Studien behandlar enbart tre av de fem punkter som BBR baseras på. Utveckling och spridning av brand och rök inom byggnadsverket ska begränsas, spridning av brand till närliggande byggnadsverk ska begränsas och hänsyn ska tas till räddningsmanskapets säkerhet vid brand. Det finns erfarenheter kring bränder i däcklager men ingen samlad bild av hur däckhotell bör hanteras i regelverken, eller om det är förenligt med byggreglernas intention och räddningstjänstens praktiska erfarenheter att utföra insats. Hur ska då brandskyddet utformas i däckhotell för att samhällets krav ska vara uppfyllt? I ett däcklager kan det handla om flera tusen däck som lagras samtidigt. Metodval för att besvara frågeställningarna var att utifrån verkliga däckhotell tillsammans med forskning och studier inom området, genomföra en rad olika analyser. Detta för att kunna besvara frågorna kvantitativt och/eller kvalitativt. Alla frågeställningar krävde dock flera antaganden för att vara möjliga att besvara. För att erhålla något att basera antagandena mot, genomfördes en fallstudie på verkliga däckhotell. Därefter skapades fem olika geometriska modeller baserade på de verkliga byggnaderna av volym, konstruktionsmaterial och ventilationsmöjligheter. Fallstudien visade även på stor variation på antalet däck som fanns placerade i däckhotell. Dock kan det konstateras att brandbelastningen i ett däckhotell överskrider 1600 MJ/m2 golvarea. Det konstruktionsmaterial byggnaden är uppförd med har stor inverkan på temperaturen i brandrummet. Däckhotell uppförda med en betongkonstruktion ger bättre förutsättningar för de brandavskiljande komponenterna att upprätthålla den brandbegränsande funktionen, detta i jämförelse med ett däckhotell uppfört av plåt med isoleringskärna. En brandcellsgräns som utsätts för den temperaturutveckling som sker i byggnad med väggar och tak av plåt-/isoleringskonstruktion, kommer eventuellt inte att begränsa brandspridningen under avsedd tid. De två skyddsbarriärerna som anges i BBR för att begränsa brandspridning mellan byggnader är skyddsavstånd eller att ytterväggen utformas som en brandcellsgräns, men där funktionen av en brandcellsgräns blir beroende av byggnadens konstruktionsmaterial. Fungerande skyddsavstånd är under förutsättning att öppningarna i fasad är begränsade och inte är större än en normal garageport. Syftet med att skydda närliggande byggnader uppfylls därmed inte. Skyddsavståndet bör vara i relation till arean på möjliga öppningar istället för ett fast värde. Ska skyddsavståndet vara fast bör det ske reglering av arean på möjliga öppningar och begränsa storleken eller kritisk strålningsnivå som får uppkomma på närliggande byggnad. Granskning av räddningsmanskapets säkerhet var en jämförelse mellan BBR och intervjuer på hur en räddningsinsats skulle kunna genomföras. Det som diskuterades var vilka risker branden och byggnaden utgör, samt hur dessa kan påverka genomförandet av insatsen. Brandtekniska åtgärder för att ta hänsyn till räddningsmanskapets säkerhet vid insats finns inte i erforderlig omfattning, vid brandteknisk projektering enligt förenklad dimensionering. Utan tidig detektion är risken överhängande att branden är för omfattande för att användning av invändiga brandposter för begränsning ska kunna vara möjlig. Dock är den enskilt viktigaste åtgärden för räddningsmanskapets säkerhet är att säkerställa tillgången till rätt mängd släckvatten vid byggnaden. Däckhotell placerade i containers är den enda byggnadsgeometri vilken kan projekteras enligt förenklad dimensionering. Den lagringsmetoden ger bäst möjlighet till en lyckad räddningsinsats och låg riskbild, och de är den enda modellen där brandcellsgränser helt klart skulle uppfylla sitt syfte både i klass EI 30 och EI 60. Containers har normalt inga fönster eller andra likvärdiga öppningar. / The aim of the thesis is mainly to investigate the risks that exist in case of fire in tire hotels and to evaluate whether society's requirements for fire protection in buildings are enough to manage this level of risk. Society's requirements in the study are Boverket's building regulations, BFS 2011:6 with amendments up to BFS 2020:4, (BBR) and the requirements that takes place in accordance with simplified design. The requirements in BBR have been quantified to enable a comparison between BBR and the actual conditions found in tire hotels. The study only treats three of the five items which BBR is based on. Development and spread of fire and smoke within the construction works is limited, spread of fire to adjacent construction works is limited and consideration has been taken to the rescue team's safety in case of fire. It exists some experience of fires in tire storage, but not a general picture of how a tire hotel should be design according to the building regulations, nor if it´s compatible with the building regulations' intention or the rescue team's practical experience of carrying out a rescue operation. The question is how the fire protection should be designed in tire hotels so that society's requirements can be fulfilled? When it can be thousands of tires which are stored at the same time in a tire hotel. The method to answer the questions was to carry out a few different analyses based on real tire hotels, together with research and studies in this area, so the questions could be answered quantitatively and/or qualitatively. However, all questions required some assumptions to be answered. To obtain something to base the assumptions against, a case study on real tire hotels was conducted. Five different geometric models were therefore created based on the buildings in terms of volume, construction materials and ventilation openings. The case study also showed a great variation in the number of tires that were stored in the hotels. Even with the variation, it can be stated that the fire load in a tire hotel exceeds 1600 MJ/m2 per floor area. The buildings construction material has a big impact on the fire temperature in the room. Tire hotels with a concrete construction provide better conditions for the fire-separation components to maintain the limiting function, in comparison with a construction of metal sheets with a core of insulation. A fire compartment boundary that is exposed to a temperature rise that occur in a metal structure, may not have the function over time it supposed to limit the spread of fire to other rooms during the intended time. BBR specifies two protective barriers to limit the spread of fire to adjacent construction, which are safety distances or that an exterior wall is designed as a fire compartment boundary. The function to limited fire spread by a fire compartment boundary is dependent on the building's construction material to fulfill its purpose. For a safety distance to work, the openings in the facade must be limited and not larger than a normal garage door. The purpose of protecting adjacent construction is therefore not fulfilled. The safety distance should be in relation to the area of ​​ openings instead of a fixed value. If the safety distance is a fixed value, the areas of openings should be regulated, if not, the size of the critical radiation that occur on an adjacent construction should be limited. Examination of the rescue team's safety was a comparison between BBR and interviews on how a rescue operation could be carried out. Under the interviews it was discussed what type of risks that are caused by the fire and the building, and how these risks can affect the implementation of the operation. The fire technical arrangements do not fulfill its purpose, to create the level of safety that are required for the rescue team when the fire technical design is according to a simplified design. Without early detection, the risk is imminent that the fire is too large for a person to use an indoor fire hydrant. The most important arrangements for the safety of the rescue team are however to ensure access to the right volume of water near the building. Tire hotels placed in containers are the only type of building which can be projected according to simplified design. This storage method provides the best opportunity for a successful rescue operation with a low risk.  Containers are also the only geometric model where fire compartment boundary would clearly fulfill its purpose, in both class EI 30 and EI 60. Containers have normally no windows or other equivalent openings.
878

Opportunities and risks of digitalization in agriculture

Paetow, Hubertus 15 November 2016 (has links)
No description available.
879

Lebensqualität als Bewertungsparameter für Lebensrisiken

Proske, Dirk, Curbach, Manfred, Köhler, Ulrike 28 February 2007 (has links)
The paper focuses on risk presentation with regard to the loss of human life. Several measures of risk, such as F-N diagrams, the probability of loss of life and days of lost life expectancy are introduced. All of these measures are specialised for different types of loss. In addition, quality-of-life parameters can be understood as measures of risk. In contrast to the afore-mentioned measures of risk, quality-of-life parameters are able to cover the entire field of risk to human life. If this is true, then the efficiency of all safety actions can be compared, regardless of their specific field. This would also permit competition among safety actions across an entire society and should yield not only improvements for safety, but also an increase in the quality of life within that society. / Der folgende Beitrag befasst sich mit der Darstellung von Risiken für Menschen. Dazu werden verschiedene Risikoparameter, wie Sterbewahrscheinlichkeiten, F-N-Diagramme und das Konzept der verlorenen Lebensjahre, vorgestellt. Weiterhin können Lebensqualitätsparameter, die in den unterschiedlichsten Fachbereichen entwickelt wurden, als Risikoparameter verstanden werden. Während die zuerst genannten Risikoparameter im Wesentlichen auf einen Aspekt eines Schadens ausgerichtet sind, können Lebensqualitätsparameter alle Formen von Verlusten oder Nachteilen erfassen. Damit wird der Vergleich von risikoverringernden Maßnahmen unabhängig vom Fachbereich einer Maßnahme möglich. Ein solcher Ansatz erlaubt den Wettbewerb aller Schutzmaßnahmen innerhalb einer Gesellschaft und müsste zu einer Erhöhung der Sicherheit und der Lebensqualität führen.
880

Användning av flygaska i vattenbyggnadsbetong / The use of fly ash in hydraulic concrete

Abdulbaki, Mohammad, Mammar Chaouche, Abdelah January 2015 (has links)
Vattenbyggnadsbetong används som en samlande beteckning på betongkonstruktioner relaterade till vattenkraftanläggningar, dammar och tyngre anläggningar. Med stor framgång har man använt betong under mycket lång tid för dessa typer av konstruktioner. Dessa konstruktioner ställer höga krav på betongens kvalitet och konstruktionsutformning eftersom de förväntas ha en livslängd på ett hundra år eller mer.   Vid gjutning så utsätts betongen för en temperaturstegring som kan leda till sprickbildning i den nygjutna konstruktionen. Eftersom temperaturstegringen är den primära orsaken till sprickrisken så kan man använda olika metoder för att minska detta. Ett verksamt sätt för att minska temperaturstegringen är att försöka hålla cementhalten i betongen så låg som möjligt, eftersom man vid adiabatiska förhållanden kan säga att den totala temperaturstegringen är direkt proportionell mot cementhalten i betongen. Ett verksamt sätt är att minska denna temperaturstegring är att använda sig utav en del flygaska istället för cement. Flygaska är en pulvermassa som fås vid tillverkning av el- och värmeproduktion på kolkraftverken och kraftvärmeverken. Flygaska är ett puzzolant material vilket innebär att det reagerar med kalciumhydroxid och vatten, och kan på så vis delvis ersätta klinker i cement.   Syftet med denna rapport är att ge en ökad förståelse i hur flygaska påverkar vattenbyggnadsbetong. Genom att läsa denna rapport så får man till en början grundläggande kunskaper om vad betong, vattenbyggnadsbetong och flygaska är för något. Vidare avsnitt som behandlas är sprickbildning i vattenbyggnadsbetong, allmän kunskap följt utav orsaker och åtgärder. En jämförelse har gjorts mellan en typisk vattenbyggnads konstruktionsdel, med respektive utan flygaska. Det som jämförts är hur konstruktionen påverkats med respektive utan flygaska med avseende på hållfasthet, beständighet och risk för sprickbildning. Vidare så har temperatursprickberäkningar utförts med programmet HACON. Syftet med beräkningarna var att visa hur olika parametrar med respektive utan flygaska påverkar risken för sprickbildning i en typisk vattenbyggnadskonstruktion.   Resultatet av temperaturberäkningarna visar att man får en lägre temperaturutveckling i en monolit gjuten med flygaska och anläggningscement jämfört med en monolit gjuten med anläggningscement utan flygaska. I och med den reducerade temperaturutvecklingen så uppstod det lägre spänningar i flygaskemonoliten. I undersökningen som utförts i denna rapport visar resultatet att det uppstår dragspänningar som överskrider draghållfastheten i monoliten utan flygaska och därmed spricker konstruktionen. I monoliten som undersökts med flygaska som sprickförebyggande åtgärd uppstår dragspänningar som är lägre än draghållfastheten och därmed spricker inte konstruktionen. Resultatet visar att sprickrisken i en typisk vattenbyggnadskonstruktion kan reduceras med flygaska som sprickförebyggande åtgärd. / Engineering Concrete is used as a collective term for concrete structures related to the hydropower plants, dams and heavier plants. With great success, concrete has been used for a very long time for these types of structures. These constructions make high demands on the concrete quality and construction design as they are expected to have a lifetime of a hundred years or more.   In casting such concrete is exposed to a temperature which can lead to cracking of the newly cast structure. Because the temperature rise is the primary cause of cracking, you can use various methods to reduce this. An effective way to reduce the temperature rise is to try to keep the cement content in the concrete as low as possible, because at the adiabatic conditions may say that the total temperature rise is directly proportional to the cement content in the concrete. An effective way to reduce the temperature rise is to use out some fly ash instead of cement. Fly ash is a powder mass obtained in the production of electricity and heat in coal-fired plants and cogeneration plants. Fly ash is a puzzolanic material which means that it reacts with calcium hydroxide and water, and can thus partially replace cement clinker.   The purpose of this report is to provide a better understanding of how the fly ash affecting hydraulic concrete. By reading this report you will get at first a basic knowledge of what the concrete, hydraulic concrete and fly ash are. Furthermore, the section that dealt with the cracking of the hydraulic concrete, general knowledge followed out causes and remedies. A comparison has been made between a typical water building structural component, with and without fly ash. What has been compared are how the construction affected with and without fly ash on strength, resistance and the risk of cracking. Furthermore, the temperature dot calculations performed with the program HACON. The purpose of the calculations was to show how the different parameters with and without fly ash affects the risk of cracking of a typical hydraulic structures.   The result of the temperature calculations show that you get a lower temperature development in a monolith cast with the fly ash and the construction cements compared to a monolith molded with construction cement without fly ash. With the reduced temperature development arose lower tensions in the flyashmonolith. In the survey carried out in this report, the results show that there is tension that exceeds the tensile strength of the monolith without fly ash and thereby bursting the structure. The monolith examined with fly ash as crackreducing action occurs tensile stresses which are lower than the tensile strength and thus does not crack structure. The results show that the cracking in a typical hydraulic structures can be reduced with fly ash.

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