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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

En utvärdering av ett nyutvecklat betongbjälklag för fler bostadshus / An evaluation of a newly developed concrete floor for apartment buildings

Ali, Hussam Jader, Manta, Teofil January 2014 (has links)
Utvecklingen av framtidens flerbostadshus ställer höga krav på en bjälklagslösnings tekniska egenskaper. Plattbärlagsbjälklaget som idag utgör det vanligaste förekommande bjälklagsvalet vid uppförandet av flerbostadshus kan ses som en lösning som kombinerar en god bärförmåga med stora möjligheter ur teknisk synpunkt. Målet med denna undersökning har varit att jämföra det traditionella plattbärlaget med en nyutvecklad bjälklagslösning baserad på produkten förspänt håldäcksbjälklag (HD/F). Jämförelsen har utgått från de aktuella kraven som enligt Boverkets byggregler (BBR) idag ställs på bjälklag och fokuserat på aspekter ur ljud, brand och fuktsynpunkt. Dessutom har jämförelsen beaktat de maximala spännvidder som respektive lösning kan dimensioneras för. Resultatet av de genomförda undersökningarna visade på att den nyutvecklade bjälklagslösningen är tillräckligt konkurrenskraftig för att i framtiden få ett större användande inom flerbostadshus. Medan plattbärlagets fördelar utmärker sig ur ljudsynpunkt möjliggör dock användandet av den nyutvecklade lösningen längre spännvidder och kortare torktider. / The development of apartment buildings puts high demands on the technical characteristics of floor systems. The lattice girder system which today represents the most commonly utilized floor system when building apartment buildings, is characterized by a good load-bearing ability along with great opportunities from a technical point of view. The aim of this analysis was to compare the traditional lattice girder system with a newly developed floor system based on hollow core slabs. The comparison is based on the current technical requirements set by Boverkets byggregler (BBR) and has its main focus on subjects related to sound, fire and moisture matters. The comparison has also accounted for the maximum spans which can be used for each solution respectively. The results of the investigation show that the newly developed floor system is competitive enough to be used in future apartment buildings. While the advantages of the lattice girder system are distinctive from a sound point of view, the utilization of the newly developed floor solution enables longer spans and shorter curing time.
32

Tvärkraftskapacitet för håldäck med en igjuten kanal / Shear Strength Capacity of Hollow-Core Slabs with One Core-Filled

Wester, Anna, Fröling, Moa January 2024 (has links)
Purpose: The purpose of the project is to modify the calculation model for the shearstrength capacity of Strängbetong's hollow-core slabs with one core-filled and with anS-bar.Method: The study’s methodology involves provoking the shear strength capacity ofhollow-core slabs with one core-filled through experimental destructive tests of twodifferent profiles of concrete hollow-core slab. The core-filling is produced with andwithout an S-bar to analyze the S-bar’s impact on the shear capacity. The experimentsare conducted over two days with full-scale test according to SS-EN 1168:2005 AnnexJ. Based on the test result from load tests and results from the calculation model inSS-EN 1168:2005 Annex F, analysis of the shear strength capacity is conducted tocreate a modified calculation model.Results: The findings reveal that the compressive strength of the concrete exceedsexpectations. The cross-sectional dimensions of the hollow-core slab are withinapproved limits. Average calculations indicate that the S-bar increases the shear strengthcapacity, although it is difficult to verify the increase. The standard model in SS-EN1168:2005 Annex F overestimates the shear strength capacity when compared with theresults from the load tests. Modified calculation models provide shear strength capacitybelow the standard model, as well as below the theoretically calculated ultimate load formost categories.Conclusion: It is possible to modify the standard model, however the results have awide variation. With only three load tests conducted, it can be concluded that there aretoo few test results to fulfill the purpose of this study / Syfte: Syftet med projektet är att ta fram en reviderad beräkningsmodell förtvärkraftskapacitet för Strängbetongs håldäck med en igjuten kanal med S-bygel.Metod: Studiens metodik innefattar att provocera fram tvärkraftskapaciteten förhåldäck med en igjuten kanal genom experimentellt förstörande tester av två olikahåldäcksprofiler i betong. Igjutningarna tillverkas med och utan S-bygel för attanalysera deras inverkan på tvärkraften. Experimenten utförs med fullskaleprover enligtSS-EN 1168:2005 Annex J under två dagar. Utifrån provresultaten frånbelastningstesterna samt med utgångspunkt från resultaten från beräkningsmodellen iSS-EN 1168:2005 Annex F genomförs analyser av tvärkraftskapaciteten för att skapa enreviderad beräkningsmodell.Resultat: Resultaten visar att betongens tryckhållfasthet är bättre än förväntat.Håldäckens tvärsnittsmått ligger inom godkända värden. Medelvärdesberäkningar visaratt S-bygeln ökar tvärkraftskapaciteten, men det är svårt att verifiera ökningen.Standardmodellen i SS-EN 1168:2005 Annex F överskattar tvärkraftskapaciteten vidjämförelse med de belastningstest som genomförts. Reviderade beräkningsmodeller gertvärkraftskapacitet under standardmodellen, men även under den teoretiskt beräknadebrottlasten för majoriteten av kategorierna.Slutsats: Det går att revidera standardmodellen, däremot har resultaten stor spridningoch med tre belastningstest går det att konstatera att det är för få provresultat för attkunna uppfylla syftet med den här studien.
33

Push-off Tests on Shear Studs with Hollow-cored Floor Slabs.

Lam, Dennis, Elliott, K.S., Nethercot, D.A. January 1998 (has links)
The shear capacity of headed studs in precast concrete hollow-core slab construction has been determined experimentally in 12 full-scale push-off tests. The tests were used to study the effects of the size of the gap between the ends of the precast slabs, and the amount of tie steel placed transversely across the joint, and the strength of concrete infill. Under certain situations the capacity of the stud is reduced compared with that in a solid reinforced concrete slab. Maximum resistances are compared with the predictions of BS 5950 and EC4, and a reduction formula for the precast effect is derived.
34

Análise teórica e experimental de pisos mistos de pequena altura compostos por vigas metálicas e lajes alveolares de concreto / Theoretical and experimental analysis of slim floor systems composed by steel beam and concrete hollow core slabs

Souza, Patricia Tavares de 22 March 2016 (has links)
No mercado mundial existe uma visível tendência de tornar as obras mais industrializadas e racionalizadas com o objetivo de reduzir os desperdícios, acelerar a velocidade de execução das obras e garantir maior qualidade às mesmas. A adoção de elementos estruturais com certo grau de industrialização pode trazer benefícios em relação aos custos, à mão de obra, ao tempo de execução e ao impacto ambiental. Neste contexto, as estruturas mistas de aço e concreto satisfazem essa necessidade, pois tanto os elementos de aço quanto os elementos de concreto podem ser pré-fabricados, ficando apenas as etapas de içamento e montagem a serem realizadas na obra, reduzindo o uso de fôrmas e escoramentos. Os pisos mistos de aço e concreto de pequena altura caracterizam-se pelo embutimento da laje de concreto na altura do perfil de aço, sendo a principal vantagem, em relação ao piso misto convencional, a redução da altura total do composto. Portanto, este trabalho tem como objetivo analisar o comportamento de pisos mistos de aço e concreto de pequena altura com laje alveolar em concreto protendido por meio de ensaios de cisalhamento direto (push-out test) e de flexão. Na solução proposta, a transferência de esforços entre o perfil de aço e a laje alveolar foi feita por meio de conectores tipo pino com cabeça e concreto moldado no local. Os resultados demonstraram-se promissores em termos de comportamento do piso misto de pequena altura, aumentando significativamente a rigidez do sistema em relação à viga de aço isolada. Em complemento, foi desenvolvida uma simulação numérica dos modelos físicos ensaiados utilizando o pacote computacional DIANA®, fundamentado no método dos elementos finitos, na qual o modelo numérico representou adequadamente o comportamento dos pisos mistos de pequena altura, permitindo análises paramétricas. / On the world market, there is a visible tendency to turn buildings construction more industrialized and rationalized in order to reduce waste, accelerate the construction speed and ensure higher quality to them. The adoption of structural elements with a degree of industrialization can bring benefits regarding costs, labor, construction time and environmental impact. In this context, steel and concrete composite structures satisfy this need, since steel and concrete elements can be prefabricated, with only lifting and mounting steps to be performed on site, reducing use of formwork and shoring. A type of slim floor system consists in precast concrete hollow core slabs supported on the lower flange of steel beams. The major advantage of this solution, compared to conventional composite beam, is reducing the overall height of the floor. Therefore, this study aims to analyze the behavior of slim floor with prestressed concrete hollow core slabs through push-out and bending tests. In the proposed solution, the transfer of forces between steel beam and hollow core slabs was made by stud bolts and cast on site concrete. The obtained results proved to be promising in terms of slim floor behavior, significantly increasing the system stiffness regarding the isolated steel beam. In addition, a numerical modeling of the studied slim floor system was developed, using finite element based software DIANA®, in which the numerical model adequately represented the behavior of the composite beam, allowing parametric analysis.
35

Shear Behaviour of Precast/Prestressed Hollow-Core Slabs

Celal, Mahmut Sami 12 January 2012 (has links)
Shear strength of precast/prestressed hollow-core (PHC) slabs subjected to concentrated or line loads, especially near supports, may be critical and usually is the governing criteria in the design. This study presents the second phase of a research program, undergoing at the University of Manitoba, to calibrate the shear equations in the Canadian code for predicting the shear capacity of PHC slabs. This phase includes both experimental and numerical investigations using a finite element analysis (FEA) software package. The length of bearing, void shape and size, level of prestressing and shear span-to-depth ratio were investigated. The experimental results were compared to the predictions of the Canadian, American and European codes. It was concluded that the Canadian code is unduly conservative. However, the special European code for PHC slabs resulted in better and more consistent predictions. The FEA suggested that the adequate prestressing reinforcement ratio to obtain highest shear capacity ranges between 0.7% and 1.1%.
36

Shear Behaviour of Precast/Prestressed Hollow-Core Slabs

Celal, Mahmut Sami 12 January 2012 (has links)
Shear strength of precast/prestressed hollow-core (PHC) slabs subjected to concentrated or line loads, especially near supports, may be critical and usually is the governing criteria in the design. This study presents the second phase of a research program, undergoing at the University of Manitoba, to calibrate the shear equations in the Canadian code for predicting the shear capacity of PHC slabs. This phase includes both experimental and numerical investigations using a finite element analysis (FEA) software package. The length of bearing, void shape and size, level of prestressing and shear span-to-depth ratio were investigated. The experimental results were compared to the predictions of the Canadian, American and European codes. It was concluded that the Canadian code is unduly conservative. However, the special European code for PHC slabs resulted in better and more consistent predictions. The FEA suggested that the adequate prestressing reinforcement ratio to obtain highest shear capacity ranges between 0.7% and 1.1%.
37

Análise teórica e experimental de pisos mistos de pequena altura compostos por vigas metálicas e lajes alveolares de concreto / Theoretical and experimental analysis of slim floor systems composed by steel beam and concrete hollow core slabs

Patricia Tavares de Souza 22 March 2016 (has links)
No mercado mundial existe uma visível tendência de tornar as obras mais industrializadas e racionalizadas com o objetivo de reduzir os desperdícios, acelerar a velocidade de execução das obras e garantir maior qualidade às mesmas. A adoção de elementos estruturais com certo grau de industrialização pode trazer benefícios em relação aos custos, à mão de obra, ao tempo de execução e ao impacto ambiental. Neste contexto, as estruturas mistas de aço e concreto satisfazem essa necessidade, pois tanto os elementos de aço quanto os elementos de concreto podem ser pré-fabricados, ficando apenas as etapas de içamento e montagem a serem realizadas na obra, reduzindo o uso de fôrmas e escoramentos. Os pisos mistos de aço e concreto de pequena altura caracterizam-se pelo embutimento da laje de concreto na altura do perfil de aço, sendo a principal vantagem, em relação ao piso misto convencional, a redução da altura total do composto. Portanto, este trabalho tem como objetivo analisar o comportamento de pisos mistos de aço e concreto de pequena altura com laje alveolar em concreto protendido por meio de ensaios de cisalhamento direto (push-out test) e de flexão. Na solução proposta, a transferência de esforços entre o perfil de aço e a laje alveolar foi feita por meio de conectores tipo pino com cabeça e concreto moldado no local. Os resultados demonstraram-se promissores em termos de comportamento do piso misto de pequena altura, aumentando significativamente a rigidez do sistema em relação à viga de aço isolada. Em complemento, foi desenvolvida uma simulação numérica dos modelos físicos ensaiados utilizando o pacote computacional DIANA®, fundamentado no método dos elementos finitos, na qual o modelo numérico representou adequadamente o comportamento dos pisos mistos de pequena altura, permitindo análises paramétricas. / On the world market, there is a visible tendency to turn buildings construction more industrialized and rationalized in order to reduce waste, accelerate the construction speed and ensure higher quality to them. The adoption of structural elements with a degree of industrialization can bring benefits regarding costs, labor, construction time and environmental impact. In this context, steel and concrete composite structures satisfy this need, since steel and concrete elements can be prefabricated, with only lifting and mounting steps to be performed on site, reducing use of formwork and shoring. A type of slim floor system consists in precast concrete hollow core slabs supported on the lower flange of steel beams. The major advantage of this solution, compared to conventional composite beam, is reducing the overall height of the floor. Therefore, this study aims to analyze the behavior of slim floor with prestressed concrete hollow core slabs through push-out and bending tests. In the proposed solution, the transfer of forces between steel beam and hollow core slabs was made by stud bolts and cast on site concrete. The obtained results proved to be promising in terms of slim floor behavior, significantly increasing the system stiffness regarding the isolated steel beam. In addition, a numerical modeling of the studied slim floor system was developed, using finite element based software DIANA®, in which the numerical model adequately represented the behavior of the composite beam, allowing parametric analysis.
38

Utdragskapacitet Sidokoppling Håldäck

Sandahl, William, Bragsjö, Jesper January 2017 (has links)
To achieve structural integrity in precast concrete systems, connections between elements must be capable to transfer both vertical and horizontal loads which puts high demands on single ties. Hollow-core slabs are often used to stabilize the structural system which puts high demands on the connections between the slab and the buildings stabilizing units. Because of this, the connections need to withstand high tensile and shear forces. The purpose of this report is to investigate the tensile capacity of tie-connections used between hollow-core slabs that are parallel with e.g. stabilizing walls and compare with current design methods. Current design methods suggest that tensile failure will occur in the roof and bottom of the cores which provides low design capacities. Two connections are investigated through full scale pull-out tests where the results are compared with the design methods. The results from testing the tensile capacity show that the failure module occurred as suggested. However, the tests show significantly higher capacity than proposed by the design methods. Eurocodes Design assisted by testing are applied to the test result and a new design method is proposed. Both provides design values that are approximately twice as large as the values suggested in previous design methods.
39

Mateřská škola / Kindergarten

Slezák, Václav January 2020 (has links)
The subject of this diploma thesis is the building design and project documentation of a new kindergarten in Brno. It is a new detached building structure with two floors, designed on a flat plot no. 1510/1 in cadastre unit Brno – Komín. The building is constructed of clay masonry with contact thermal insulation, supported by strip foundations. Ceiling construction is made of prestressed hollow-core slabs. This object is roofed by a single-layer and double-layered, flat roof. This kindergarten is designed for 60 children divided into three sections. Two sections are located on the 1st floor together with food preparation and technical rooms. The third section is on the 2nd floor with headquarters and a common room. This project was developed using AutoCAD software. The focus during development was on the proposed layout design in accordance with the kindergarten’s operations.
40

Bytový dům, Brno - Židenice / Apartment house, Brno - Židenice

Šmíd, Václav January 2015 (has links)
Within the frame of my master's thesis I processed a project documentation for a construction of an apartment house in Brno – Židenice. The building is unattached and has 7 floors. On the ground floor there are four individual garages, cellar cubicles and a utility room. There are apartments on all other floors. On the highest floor, there is situated a singular apartment with outdoor terrace and vegetation area. The building is founded on strips made of reinforced concrete, vertical load-bearing structure is made of cermic blocks, floor structure is made of hollow core slabs and staircase is also made of prefabricated elements. The house is insulated with contact thermal insulation made of mineral wool. During the process of creating the projet, I followed all the requirements of actual regulations and legal enactments, to provide sufficient mechanical endurance and stability, health safety of the inner space as well as safety of the natural environment.

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