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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.
31

Estudo do dano por umidade de misturas densas com ligantes asfálticos convencional e modificado com polímero SBS / Study of moisture damage of conventional and polymer modified asphalt mixtures

Anitelli, Andre 12 August 2013 (has links)
O objetivo desta pesquisa foi contribuir para o entendimento sobre a suscetibilidade ao dano por umidade de misturas asfálticas densas à luz dos ensaios da ASTM D 4867 e AASHTO T 283. Para isso, foi desenvolvido um programa experimental completo que considerou a variação, em dois níveis, dos seguintes fatores: tipo de asfalto (CAP 50/70 e CAP 50/70+SBS), presença de aditivo (sem e com cal) e modo de preparo (envelhecimentos em curto e em longo prazos). O programa experimental resultou em 8 tipos de misturas asfálticas (condições experimentais) que foram caracterizadas em suas propriedades originais e após um condicionamento térmico composto de uma fase de congelamento (-18º C por 16 horas) e uma fase de descongelamento (60º C por 24 horas). A partir das análises dos resultados foi possível constatar que (i) nenhuma mistura testada foi considerada suscetível ao dano por umidade, mas a relação de resistência à tração das misturas com CAP 50/70 de ambos os métodos se encontraram no limiar dos valores limites; (ii) as misturas com asfalto modificado, em geral, apresentaram maiores valores de módulo de resiliência e resistência à tração e foram mais resistentes à ação da água; (iii) a adição de cal não promoveu mudanças notáveis nas propriedades originais, no entanto contribuiu para a manutenção ou para o aumento da resistência ao dano por umidade; (iv) os envelhecimentos em curto e longo prazos dos métodos da ASTM e da AASHTO não provocaram mudanças importantes nas propriedades originais e após o condicionamento as misturas testadas exibiram tendências de comportamentos similares. / This research presents a contribution to understanding hot mix asphalt (HMA) moisture damage susceptibility according to ASTM D 4867 and AASHTO T 283 tests. A full factorial experiment design was carried out considering the factor variations, on two levels: asphalt type (CAP 50/70 and CAP 50/70+SBS), additive presence (with or without hydrated lime) and mixture procedure (short and long term aging). The experimental program resulted in 8 types of asphalt mixes (experimental conditions) which were characterized by the original properties and after a thermal conditioning wich consisted of a freezing phase (-18 °C for 16 hours) and a thawing phase (60 °C for 24 hours). Findings indicate that (i) no one mix was considered susceptible to moisture damage, however the ITR (indirect tensile ratio) of the CAP 50/70 mixes resulted ITR near to protocol admissible values; (ii) in general, CAP 50/70+SBS mixes presented higher resilient modulus, indirect tensile strength and indirect tensile ratio values, (iii) the addition of hydrated lime did not show remarkable changes in original properties, nevertheless it contributed for maintaining or increasing the moisture damage resistance; (iv) short and long term aging procedures (ASTM and AASHTO) did not cause important changes in original properties and after conditioning the mixes showed similar behavior tendencies.
32

Estudo do dano por umidade de misturas densas com ligantes asfálticos convencional e modificado com polímero SBS / Study of moisture damage of conventional and polymer modified asphalt mixtures

Andre Anitelli 12 August 2013 (has links)
O objetivo desta pesquisa foi contribuir para o entendimento sobre a suscetibilidade ao dano por umidade de misturas asfálticas densas à luz dos ensaios da ASTM D 4867 e AASHTO T 283. Para isso, foi desenvolvido um programa experimental completo que considerou a variação, em dois níveis, dos seguintes fatores: tipo de asfalto (CAP 50/70 e CAP 50/70+SBS), presença de aditivo (sem e com cal) e modo de preparo (envelhecimentos em curto e em longo prazos). O programa experimental resultou em 8 tipos de misturas asfálticas (condições experimentais) que foram caracterizadas em suas propriedades originais e após um condicionamento térmico composto de uma fase de congelamento (-18º C por 16 horas) e uma fase de descongelamento (60º C por 24 horas). A partir das análises dos resultados foi possível constatar que (i) nenhuma mistura testada foi considerada suscetível ao dano por umidade, mas a relação de resistência à tração das misturas com CAP 50/70 de ambos os métodos se encontraram no limiar dos valores limites; (ii) as misturas com asfalto modificado, em geral, apresentaram maiores valores de módulo de resiliência e resistência à tração e foram mais resistentes à ação da água; (iii) a adição de cal não promoveu mudanças notáveis nas propriedades originais, no entanto contribuiu para a manutenção ou para o aumento da resistência ao dano por umidade; (iv) os envelhecimentos em curto e longo prazos dos métodos da ASTM e da AASHTO não provocaram mudanças importantes nas propriedades originais e após o condicionamento as misturas testadas exibiram tendências de comportamentos similares. / This research presents a contribution to understanding hot mix asphalt (HMA) moisture damage susceptibility according to ASTM D 4867 and AASHTO T 283 tests. A full factorial experiment design was carried out considering the factor variations, on two levels: asphalt type (CAP 50/70 and CAP 50/70+SBS), additive presence (with or without hydrated lime) and mixture procedure (short and long term aging). The experimental program resulted in 8 types of asphalt mixes (experimental conditions) which were characterized by the original properties and after a thermal conditioning wich consisted of a freezing phase (-18 °C for 16 hours) and a thawing phase (60 °C for 24 hours). Findings indicate that (i) no one mix was considered susceptible to moisture damage, however the ITR (indirect tensile ratio) of the CAP 50/70 mixes resulted ITR near to protocol admissible values; (ii) in general, CAP 50/70+SBS mixes presented higher resilient modulus, indirect tensile strength and indirect tensile ratio values, (iii) the addition of hydrated lime did not show remarkable changes in original properties, nevertheless it contributed for maintaining or increasing the moisture damage resistance; (iv) short and long term aging procedures (ASTM and AASHTO) did not cause important changes in original properties and after conditioning the mixes showed similar behavior tendencies.
33

Qualidade de sementes de soja avaliadas pelo teste de tetrazólio: estudo de caso na empresa Dimicron / Soybean seed quality valued by test tetrazolium: a case study in the company Dimicron

Uhde, Shirlei 17 November 2014 (has links)
Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-03-03T15:30:24Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_shirlei_uhde.pdf: 798758 bytes, checksum: 087cc2c455112b068e7753167b47f0d8 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-09T17:59:02Z (GMT) No. of bitstreams: 2 dissertacao_shirlei_uhde.pdf: 798758 bytes, checksum: 087cc2c455112b068e7753167b47f0d8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-09T18:00:44Z (GMT) No. of bitstreams: 2 dissertacao_shirlei_uhde.pdf: 798758 bytes, checksum: 087cc2c455112b068e7753167b47f0d8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-09T18:00:51Z (GMT). No. of bitstreams: 2 dissertacao_shirlei_uhde.pdf: 798758 bytes, checksum: 087cc2c455112b068e7753167b47f0d8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-11-17 / Sem bolsa / O presente trabalho teve como objetivo fazer um levantamento da qualidade fisiológica de sementes de soja, das categorias S1 e S2, analisadas no Laboratório de Analises de Sementes da Dimicron Química do Brasil Ltda., usando o teste de tetrazolio, para caracterizar as características fisiológicas: viabilidade, vigor, danos mecânicos, danos por umidade, danos por percevejos, causas da perda da viabilidade, classificação do vigor, relacionar nível de sementes de mais alto vigor Para o trabalho, foram coletados os dados das analises das safras 2008/2009, 2009/2010, 2010/2011 e 2011/2012, referente às informações obtidas dos testes de tetrazólio aplicados nas amostras de lotes de sementes das categorias S1 e S2 que foram analisadas. Foram examinados os resultados de 481 lotes analisados, sendo 309 lotes da categoria S1 e 172 lotes da categoria S2. Os parâmetros empregados para avaliar a qualidade fisiológica das sementes foram: viabilidade (TZ 1-5), vigor (TZ 1-3), danos mecanicos (TZ 1-8), danos por umidade (TZ 1-8), danos por percevejo (TZ 1-8). Os resultados obtidos permitem concluir que: As maiores percentagens de lotes de alto vigor foram obtidas nas safras de 2008/2009 e 2009/2010, para ambas classes de sementes. Os danos mecânicos e de umidade são os mais freqüentes em sementes de soja. / This study aimed to survey the physiological quality of soybean seeds, S1 and S2 categories analyzed in LABORATORY analysis of seeds of Dimicron Chemistry of Brazil Ltda., Using the tetrazolium test to characterize the features physiological: feasibility, force, mechanical damage, moisture damage, bedbugs for damages, loss of viability of the causes of force classification, relate highest level of seed vigor for work, we collected data from the analysis of crops 2008/2009, 2009/2010, 2010/2011 and 2011/2012, referring to the information obtained from tetrazolium tests applied in samples of seed lots of S1 and S2 categories that were analyzed. We examined the results of 481 lots, with 309 lots category S1 and S2 172 lots category. The parameters used to evaluate the physiological quality of seeds were: viability (TZ 1-5), vigor (TZ 1-3), mechanical damage (TZ 1-8), moisture damage (TZ 1-8), damages for bug (TZ 1-8). The results showed that: The highest percentages of lots of high vigor were obtained for crop years 2008/2009 and 2009/2010, for both seed classes. Mechanical damage and humidity are the most frequent in soybean seeds.
34

Problem i högt fuktbelastade byggnader : Riskbedömning med hjälp av WUFI / Problems in buildings with high moisture load : Risk assessment using WUFI

Wong, Katilla, Bergh, David January 2012 (has links)
Många av Sveriges badhus byggda i slutet av 1900-talet börjar idag visa tecken på kraftiga fuktskador på grund av extrema inomhusklimat. Denna rapport förklarar den allmänna problematiken kring högt fuktbelastade byggnader och berör det fuktskadade badhuset Aquarena i Katrineholm.  Extrem noggrannhet krävs vid montering av ångspärr i en konstruktion, speciellt vid högt invändigt fukttillskott. Optimal placering av fuktspärren i konstruktionens varmare del innebär att fukt aldrig tillåts kondensera och därmed minimeras risken för fuktskador och negativa konsekvenser. Verkligheten visar också att om kunskaper om fukt och fuktskador prioriteras redan i ett tidigt stadium under projektering kan många hundratusentals kronor sparas. Beräkningar av fukttransport har gjorts för tidigare ytterväggskonstruktion i Aquarena (den som drabbats av skador) och nybyggd ytterväggskonstruktion (nyframtagen till återuppbyggnaden) i datorprogrammet WUFI Pro 4.2 och analyserats i WUFI Bio 3.0.  Beräkningarna visar att den tidigare väggkonstruktionen får de skador som undersökningar av den visat och att skadorna hade kunnat undgås om genomförningar i ångspärren hade utförts på ett korrekt sätt.  Vi har med beräkningar inte kunnat bevisa att alla delar i den nybyggda ytterväggskonstruktionen kommer fungera perfekt. Främst beror osäkerheten i beräkningar utförda i WUFI på att beräkningsmodellen inte är färdigutvecklad. Osäkerheter beror också på otillräcklig kännedom av egenskaper hos de simulerade materialen. Beräkningar för den nyframtagna väggkonstruktionen visar dock entydigt på bättre resultat än för den tidigare väggkonstruktionen. Det finns därför anledning att vidare utreda vilka värden på fukt och temperatur som kommer att råda över de närmaste åren. Detta bland annat för att senare kunna korrigera beräkningsmodellen efter verkligheten. / Many of Sweden's public indoor swimming pools built in the late 1900’s are beginning to show signs of excessive moisture damage due to extreme indoor climate. This report explains the general problem of high moisture-loaded buildings and involves the moisture-damaged public indoor swimming pool Aquarena in Katrineholm. Extreme care is required when assembling the moisture barrier in a structure, especially with high internal moisture content. Optimal placement of the moisture barrier in the warmer parts of the construction means that moisture is never allowed to condense, thus minimizing the risk of moisture damage and negative consequences. Reality also shows that if risks of moisture and moisture damages are assessed early in the planning process, amounts in the range of hundreds of thousands of Swedish crowns can be saved. Calculations of moisture transport have been made for the previous exterior wall structure (the one that suffered damage) and new exterior wall structure the (new design for the reconstruction) using the computer program WUFI Pro 4.2 and analyzed in WUFI Bio 3.0. Calculations show that the old exterior wall structure in Aquarena would have been able to withstand moisture damage and damages due to moisture if joints and transitions in the moisture barrier had been correctly performed.  Calculations have not proven that all elements of the newly built wall design will work perfectly. The main reason for uncertainty in calculations when using WUFI is that the calculation model is not fully developed. Uncertainty is also due to insufficient knowledge of properties of the simulated materials. However, calculations show unambiguously better results than the previous wall construction. It is therefore necessary to further investigate what values of humidity and temperature will exist over the next few years to be able to later on correct the calculation model after reality.
35

Mätfel vid fuktmätning i emissionsskadad betong / Error when performing moisture measurement in emission-damaged concrete

Orenäs Nissas, Sebastian, Rahimi, Nangyalay January 2018 (has links)
När människors hälsobesvär misstänks vara byggnadsrelaterat är det viktigt att klarlägga källan till problemet. Fukt kan vid högre nivåer ge upphov till mikrobiella eller kemiska reaktioner som orsakar emissioner från byggnadsmaterial som kan ha negativa hälsoeffekter. För att utreda om byggnaden är problemkällan görs skadeutredningar. I utredningarna är det viktigt att identifiera vilka emissioner som förekommer i inomhusmiljön för att kunna åtgärda den eventuella skadan. Med hjälp av fuktprofiler som skapas genom fuktmätningar kan det utredas om varifrån fukten kommer. En vanlig orsak i Norden till förhöjda koncentrationer av emissioner i inomhusmiljön är fuktskadade betongkonstruktioner med en pålimmad plastmatta. I en sådan konstruktion utgör plastmattan ett tätt skikt som inte låter fukten i betongen avdunsta. Betong, som är alkalisk, kan i kombination med höga fuktnivåer utlösa en kemisk process, så kallad alkalisk hydrolys, som bryter ned mjukgörare i golvlim och PVC-mattor. Detta leder till att nedbrytningsprodukterna 2-etyl-1-hexanol och n-butanol dels emitteras till inomhusluften och dels migrerar ned i betongen där de fixeras. Det är i det skedet betongen blir emissionsskadad på grund av att de kemiska ämnena som fixerats i betongen kan lagras där under en lång tid och kan om förhållandena förändras, exempelvis vid renovering, avge dessa ämnen till inomhusluften. Eftersom 2-etyl-1-hexanol och n-butanol utgör majoriteten av nedbrytningsprodukterna, används de därför som indikatorämnen vid skadeutredningar. Om indikatorämnena upptäcks i inomhusluften är det troligt att en skada i golvkonstruktionen har inträffat och detta kontrolleras då med fuktmätningar. Problemet med fuktmätningar i emissionsskadad betong är dock att det befaras av fuktskadeutredare att dessa indikatorämnen påverkar fuktmätningarna genom att man mäter till en lägre relativ fuktighet (RF) än vad det faktiskt är. Examensarbetet är utformat som ett experimentellt arbete med fuktmätningar som utförts i Polygon AK:s laboratorium. I laborationerna testades huruvida indikatorämnena, 2-etyl-1-hexanol samt n-butanol, påverkar fuktmätningar. Detta gjordes genom att prover med ren betong först RF-bestämdes för att sedan droppa i ovanstående ämnen i proverna och därefter följdes utvecklingen i RF. Vidare kontrollerades eventuell drift i mätinstrumenten genom egenkontroller både före och efter varje uppföljning. Mätresultaten från gjorda försök visade att den effekt som befarats av skadeutredare ej märkts av, det vill säga att indikatorämnena skulle ha en påverkan genom att fuktnivån mäts till något lägre jämfört med den verkliga fuktnivån. Effekten påvisades varken genom lägre uppmätta fuktnivåer eller genom mätinstrumentens drift. / When people's illness are suspected to be building-related, it is important to clarify the source of the problem. Moisture at higher levels can trigger microbial or chemical reactions which causes emissions from building materials that may have adverse health effects. In order to investigate whether the building is the source of the problem or not, indoor environment investigations are conducted to investigate the matter. In the investigations it is important to identify what kind of emissions that occurs in the indoor environment in order to fix the possible damage or damages. Using moisture profiles created with moisture measurements, it is possible to determine where the moisture comes from. A common cause in the Nordic countries for increased concentrations of emissions in the indoor environment is moisture-damaged concrete structures with a glued plastic mat. In such constructions, the plastic mat is a compact layer that does not allow the moisture in concrete to evaporate. Concrete, which is alkaline, can in combination with high moisture levels trigger a chemical process, called alkaline hydrolysis, which degrades plasticizers in floor adhesives and plastic mats. This results in the degradation products 2-ethyl-1-hexanol and n-butanol, which are being emitted to the indoor air and partly migrating down into the concrete where they are fixed. At that moment the concrete gets emission-damaged because of the degradation products that has been fixed into the concrete where they can be stored for a long time and can with changed conditions, for instance during renovation, emit these degradation products to the indoor air. Since 2-ethyl-1-hexanol and n-butanol constitutes the majority of degradation products, they are therefore used as indicators during damage investigations. If the indicators are detected in the indoor air, it is likely that a damage has occured in the floor construction and this is later checked with moisture measurements. However, the problem with moisture measurements in emission-damaged concrete is that some investigators fears that these indicators affects the moisture measurements by measuring a lower relative humidity (RH) than it actually is. The thesis is structured as an experimental work with moisture measurements performed in Polygon AK's laboratory. In the laboratory it was tested whether the indicators, 2-ethyl-1-hexanol and n-butanol, affects moisture measurements. This was done with specimens of pure concrete by first determining the RH followed by dropping the indicators into the samples and then the development in RH was followed. Furthermore, eventual drifting in the measuring instruments was checked before and after each follow-up. The measurement results from the experiments showed no effect of what the damage investigators feared of, that the indicators would have an impact by measuring the moisture level lower than the actual moisture level. The effect was not detected either by lower measured humidity levels or by drifting of the measuring instruments.
36

Analys av lokala otätheters påverkan i ytterväggskonstruktioner : Analys och riskbedömning med programmen WUFI and WUFI-Bio / Analysis of local leakages' effect in exterior wall constructions : Analysis and assessment with the programs WUFI and WUFI-Bio

Kalef, Raoua, Khalil, Nour January 2013 (has links)
Många byggnader är idag fuktskadade. Fuktskador uppstår på så väl nya som gamla byggnader. Idag provtrycker man hus för att få ett värde på dess täthet, men många hus som klarar täthetskraven drabbas ändå av fuktskador. Detta beror på att otätheterna är lokala på en eller flera delar av klimatskalet bortsett från otätheter vid anslutningar.   En studie har gjorts på två väggtyper; en standardvägg och en passivhusvägg. Denna undersökning har begränsats till väggar för småhus. Undersökningen syftar till att ta fram vart gränserna går innan mögeltillväxt påvisas för olika håldiametrar i plastfolien. Jämförelse gjordes för dessa väggkonstruktioner i städerna Kiruna, Stockholm och Lund. Simulering av konstruktionerna i de olika städerna gjordes i programmet WUFI Pro 5,0 med en 5-årsperiod där resultaten sedan analyserats i WUFI-Bio 3,1 RC för riskbedömning av mikrobiell tillväxt. Resultat åskådliggör att konstruktioner med tjockare isolering belägna längre upp i landet lättare kan råka ut för skador orsakade av fukt. / Many buildings today are moisture damaged. Moisture damage occurs to new as well as old buildings. Nowadays we test the dense of the building with measurement of the air flow under pressure, but still many of these building structures that meet the dense requirements are still affected by dampness. This is because the leaking points are situated at one or other parts of the building shell other than at the connections.A study has been made on two wall types: a standard wall and a passive house wall. This investigation has been confined to walls of houses. The study aims to develop each boundaries before mold growth demonstrated for different hole diameters in plastic foil. Comparison was made for these wall structures in the cities Kiruna, Stockholm and Lund.The comparison of the wall structures in the different towns was done with a simulation program WUFI Pro 5.0 for a 5-year period. Results were then analyzed in WUFI Bio 3.1 RC, program for risk assessment of microbial growth.Results illustrate that structures with thicker insulation located further up in the country can more easily encounter damage caused by moisture.

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