Dimensionierung und Konstruktion von Bewehrungstextilien für die Anwendung in Textilbeton werden in Abhängigkeit von der resultierenden Last im Bauteil durchgeführt. Um aus der Vielzahl möglicher Varianten von Bewehrungsstrukturen die passenden auszuwählen, wird ein reduziertes Beschreibungsschema zur Auswahl herangezogen. Als Anwendungsbeispiel wird eine komplexe Bewehrungsstruktur beschrieben, die für dünnwandige, selbsttragende Sandwichelemente genutzt wird. Die Sandwichelemente werden als Wandund Dachkonstruktion für ein 20 m² großes modulares Gebäude eingesetzt. Die Bewehrungsstrategie für die Elemente sowie die Herstellungstechnik und Prüfverfahren für die Bewehrung werden beschrieben. Zur Langzeitüberwachung der Sandwichelemente wird ein Monitoring-System verwendet.

Made available in DSpace on 2015-05-07T14:49:18Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1971654 bytes, checksum: ef95313e4fdd4ef38d4603a35f58473b (MD5) Previous issue date: 2010-03-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This paper is the formulation of a Proposed Zoning and Load Capacity Recreation to the Parque Estadual Marinho de Areia Vermelha that currently is very touristy. The amendment was based on the class Anthozoa diversity. To the recognition of the animals s diversity, the area was divided into 3 quadrants and 5 transects of 100 m, in each one were drawn. All individuals found in 50cm to the right and 50 cm to the left of the transect line were analyzed. This gave a basis for knowing the most diverse area of the park and served as a subsidy for the proposal of environmental zoning. To prepare the zoning map, the image was captured from Google Earth and used the modules SPRING, IMPIMA and SCARTA version 5.0.5. The captured images from Google Earth were saved in TIF format and were inserted in the module IMPIMA, which was used to save images in the native format SPRING. Some factors were taken into consideration as sites already used for tourism, biodiversity hotspots, areas of influence, diving sites, actions of waves,currents and fishing. Based on these features and taking into account some of the activities already undertaken in the park, the environmental zoning was created. From this zoning was proposed carrying capacity for recreational areas where tourism activities were allowed. For the load capacity was used the methodology of Cifuentes (1992) adapted to the conditions of the marine environment. For the two proposals, was also taken into account, the point of views of the professionals working with craft and environmental awareness of tourists visiting the area. As results we observed that the scleractinea corals present in the area were: Favia gravida, Porites astreoides and Siderastrea stellata and as Gorgoniacea coral species we had Muriceopsis sulphurea. Among zoanthids the species Palythoa caribaeorum, Protopalythoa variabilis and Zoanthus sociatus were found. The most rich in biodiversity was quadrant 2. The areas suggested in this proposed zoning were: Touristic Recreational Use Zone, Special Use Zone, Preservation of Marine Life Zone, Traditional Use Zone, Traditional and Recreational Use Zone and Cushioning Zone. The load capacity was designed for the use of the areas of Touristic Recreationl areas, which resulted in 400 visits per day, to the Special-Use area which can have 281 visits per day and the Traditional and Recreational Use Zone, with 544 visits per day, totalizing 1225 people daily around the park. With the questionnaires applied to tourists and professionals working on the boats, was detected that the application of environmental education is of paramount importance. / Esta dissertação consiste na formulação de uma Proposta de Zoneamento e de Capacidade de Carga Recreativa para o Parque Estadual Marinho de Areia Vermelha, que atualmente é muito explorada turisticamente. A proposta aqui apresentada foi feita com base na diversidade de espécies da classe Anthozoa. Para reconhecimento da diversidade de animais a área foi dividida em 3 quadrantes e foram traçados 5 transectos de 100m em cada um, em que foram anotados todos os indivíduos encontrados 50cm à direita e 50 cm a esquerda da linha do transecto. Isso deu base para se saber a área mais diversa do parque e serviu de subsídio para a proposta de zoneamento ambiental. Para a confecção do mapa do Zoneamento, foi capturada a imagem do Google Earth e utilizados os módulos SPRING, IMPIMA e SCARTA versão 5.0.5. As imagens capturadas no Google Earth foram salvas em formato TIF e inseridas no módulo IMPIMA, que foi utilizado para salvar as imagens em formato nativo do SPRING. Alguns fatores foram levados em consideração como locais já utilizados para o turismo, focos de biodiversidade, áreas de influência, locais para mergulho, ações das ondas e correntes e pesca artesanal. Com base nessas características e levando em conta algumas atividades já desenvolvidas no Parque o zoneamento ambiental foi criado. A partir deste zoneamento foi proposta a capacidade de carga recreativa para as zonas onde as atividades turísticas foram permitidas. Para a capacidade de carga foi utilizada a metodologia de Cifuentes (1992) adaptada para as condições do ambiente marinho. Para as duas propostas, foi levado em consideração também a opinião dos profissionais que trabalham com embarcações e a percepção ambiental dos turistas que visitam a área. Como resultados, verificamos que as espécies de corais escleractíneos presentes foram: Favia gravida, Porites astreoides e Siderastrea stellata e espécies de corais gorgonaceos tivemos Muriceopsis sulphurea. Entre os zoantídeos foram encontradas as espécies de Palythoa caribaeorum, Protopalythoa variabilis e Zoanthus sociatus. O quadrante mais diversificado foi o quadrante 2. As zonas sugeridas na proposta de zoneamento foram: Zona de Uso Turístico Recreativo, Zona de Uso Especial, Zona de Preservação da Vida Marinha, Zona de Uso Tradicional, Zona de Uso Tradicional e Recreativo e Zona de Amortecimento. A capacidade de carga foi elaborada para as áreas de Uso Turístico Recreativo, que resultou em 400 visitas por dia, Zona de Uso Especial, podendo ter 281 visitas por dia e a Zona de Uso Tradicional e Recreativo, com 544 visitas por dia, totalizando 1225 pessoas diárias em todo o parque. Com os questionários aplicados aos turistas e aos profissionais que atuam nos barcos foi detectado que um trabalho de educação ambiental é de fundamental importância.

La corrosion sous contrainte (CSC) est un phénomène synergique d'endommagement qui résulte d'un processus de corrosion (dissolution, adsorption) et d'une rupture mécanique (fissuration). Les mécanismes de couplage mécano-électrochimique en pointe de fissure nécessaires à la compréhension du phénomène sont encore mal connus puisqu'ils dépendent du système d'étude (métal/milieu agressif) et font intervenir de nombreux facteurs mécaniques et électrochimiques. Dans cette thèse, nous nous proposons d'étudier les interactions réciproques entre la dissolution et l'état de contrainte mécanique en pointe de fissure (facteurs d'intensité des contraintes) pour le cas du Zircaloy-4 en milieu aqueux halogéné. Les éprouvettes sont d’abord pré-fissurées par fatigue à l’air avec la technique du Load-Shedding, ce qui permet alors de maîtriser le facteur d’intensité des contraintes résiduel de pré-fissuration par fatigue. Ensuite, une pré-oxydation thermique est réalisée pour produire une couche de film passif sur les surfaces de l’éprouvette. Les réactions électrochimiques sont alors concentrées en pointe de fissure qui induit également une concentration des effets mécaniques. Des techniques de corrélation d'images sont développées dans le but d'identifier les facteurs d'intensité des contraintes et d'estimer la longueur de fissure en temps réel. Ainsi des essais originaux de CSC, permettant d'imposer les facteurs d'intensité en pointe de fissure, sont conduits et les résultats montrent alors clairement les effets synergiques entre l'évolution des mesures mécaniques et des courants de dissolution. D'autre part, l'existence d'un facteur d'intensité des contraintes seuil de propagation en CSC, présentant une forte dépendance à l'histoire de chargement et à la variation de l'état de contrainte locale en pointe de fissure (variation des facteurs d'intensité des contraintes), est mise en évidence. Ceci montre alors que la plasticité doit évoluer pour que la dissolution se produise. Ainsi, le temps caractéristique d'arriver de nouvelles dislocations en pointe de fissure ne doit pas dépasser la durée caractéristique des réactions de passivation. Enfin sur la base des résultats expérimentaux, un modèle de loi de propagation phénoménologique de fissure en CSC est proposé et ses paramètres sont identifiés et validés à partir de différents essais de CSC. / Stress corrosion cracking (SCC) is a damage phenomenon which results from the synergy between corrosion process (dissolution, adsorption) and mechanical fracture (crack propagation). Although this phenomenon is well known, its modelling is still a challenging issue, especially concerning mechano-electrochemical coupling mechanisms at crack tip, because it depends on model system (metal/aggressive media) and large number of mechanical and electrochemical factors. In this thesis, mutual interactions between dissolution and the stress state around the crack tip (stress intensity factor) are studied in the case of Zircaloy-4 in aqueous halide solution. Samples are first pre-cracked in air by using fatigue load-shedding procedure to control the stress intensity factor. Then, pre-oxidization is used to produce a thin protective passive layer on their surface. The electro-chemical reactions are thus concentrated at the crack tip which also induces a concentration of the mechanical effect. During the test, digital images of the sample surface are acquired. Digital Image Correlation is performed a posteriori in order to obtain the evolution of the crack length and the stress intensity factors. Further, a specific procedure is developed in order to perform the DIC analysis while the test is running. This allows to control the load so that a given value of the stress intensity factor is prescribed. With this innovative experimental technique, we perform experimental tests that allow to discriminate the effects between different stress corrosion cracking mechanisms. It is suggested that once a critical anodic polarization is exceeded, the crack growth rate depends on the stress intensity factor but also on its time derivative. Indeed, a threshold effect is obtained on the stress intensity factor, meaning that plasticity must increase for the dissolution reaction to occur, but also on its rate meaning that time for plasticity to produce new dislocations must not exceed the characteristic duration of the passivation reaction. A phenomenological crack propagation model is proposed and its parameters are then identified and validated from the experimental measurements during SCC tests.

Le renforcement des fondations par soil mixing consiste à créer dans le sol des colonnes à module mixte obtenues en mélangeant le sol sur place avec un liant hydraulique. Ces colonnes, qui possèdent des caractéristiques mécaniques entre celles du béton et celles du sol, permettent d’améliorer la portance du sol d’assise et réduire les tassements excessifs des structures surjacentes. Ce travail de recherche consiste en une étude du comportement des fondations superficielles renforcées par des colonnes de soil mixing. Il vise à mettre en exergue les améliorations que cette technique apporte en termes d’augmentation de la capacité portante et de réduction des tassements. Dans une première étape, un matériau de soil mixing est formulé à partir d’un sable d’Hostun et d’un ciment CEM III. Une étude préalable a été réalisée pour déterminer les caractéristiques mécaniques de ce matériau de soil mixing, du sable d’Hostun, ainsi que les propriétés d’interface sable d’Hostun - soil mixing. Dans une seconde étape, une cuve expérimentale a été conçue pour permettre la réalisation de la procédure expérimentale du renforcement du sable par des colonnes de soil mixing. Plusieurs configurations du modèle physique ont été testées: Il s’agit d’essais de chargement sur fondations superficielles reposant sur un massif renforcé ou non. La taille de la semelle, le nombre des colonnes de renforcement, leurs âges, la densité de sol ainsi que le type de renforcement (renforcement type fondation mixte ou inclusion rigide) sont des paramètres dont l’effet a été étudié. Les essais de caractérisation, la conception du modèle expérimentale ainsi que les essais de chargement réalisés ont permis de mieux comprendre le comportement du sol renforcé. La connaissance des paramètres géomecaniques du sol et du matériau de soil mixing a permis de comprendre l’évolution de la capacité portante des semelles en présence des colonnes de renforcement. La présence d’un horizon porteur dans lequel les colonnes sont encastrées fait augmenter significativement la capacité portante de la semelle. Dans le cas du renforcement type inclusions rigides, l’augmentation de l’épaisseur du matelas granulaire réduit la capacité portante de la semelle renforcée. Cependant, elle fait augmenter la contribution des colonnes de renforcement dans la reprise des efforts appliqués sur la semelle. Une confrontation a été réalisée entre les résultats expérimentaux des essais de chargement et les résultats provenant d’un modèle éléments finis mis en œuvre avec le logiciel Abaqus. Les paramètres utilisés proviennent de nos essais de caractérisation réalisés dans le cadre de cette étude. Le modèle a présenté des résultats satisfaisant et a réussi de reproduire le comportement physique des semelles renforcées. Le modèle n’a non seulement réussi à reproduire les essais de chargement à l’échelle d’une colonne, mais aussi à l’échelle des semelles renforcées par une seule colonne et par quatre colonnes. / The reinforcement of shallow foundations by soil mixing consists on mixing the soil beneath with a hydraulic binder in order to obtain columns with mixed modulus. These columns, which have mechanical properties bounded between those of concrete and those of soil, can improve the soil bearing capacity and reduce excessive settlements as well. This research work is a phenomenological and quantitative study of the behavior of shallow foundations reinforced by soil mixing columns. It leads to analyze and highlight improvements that this technology brings in terms of bearing capacity increase and settlement reduction. In a first step, a soil mixing material is formulated from Hostun sand and cement CEM III. A preliminary study is conducted to determine the mechanical characteristics of the soil mixing material, Hostun sand and sand – soil mixing interface. In a second step, an experimental tank is designed to allow the installation of 1 m3 of hostun sand under different density. The experimental procedure allows also the installation of soil mixing columns that reinforce the soil. Finally a device is installed in order to carry on loading tests. Different configurations of the physical model were tested. Loading tests are carried on soil mixing columns and on unreinforced and reinforced shallow foundations. Size of the foundation, number of reinforcing columns, their age, soil density and type of reinforcement (rigid inclusion or mixed foundation) are parameters we change during this study. The characterization tests, the design of the experimental model, and the loading tests helped us to better understand the behavior of the reinforced soil. The knowledge of geomechanical parameters of soil and soil mixing material allowed us to understand the evolution of the bearing capacity of the reinforced foundations. The presence of a carrier horizon, in which the tip columns is embedded, leads to significantly increase the bearing capacity of the foundation. In the rigid inclusions reinforcement case, the increasing of granular mattress thickness reduces the bearing capacity of the reinforced foundation. However, it increases the part of the loading transmitted to soil mixing columns. A comparison was made between the experimental results of loading tests and the results of a finite element model implemented with Abaqus software. Model parameters are taken from our material characterization study. It is proven that the model developed is able to reproduce not only loading tests at column scale, but alsot at reinforced foundations scale.

The focus of this thesis is the construction of a single girder overhead crane. The goal is to render a crane construction according to preset parameters. The parameters include a lifting power of 8,000 kg, a 10,000 mm reach, a 2,400 mm wheelbase and a stroke of 8,000 mm. The thesis includes brief theoretical research focused on overhead cranes, their various types and description of their main components. Brief description of chosen parameters for the construction itself follows. The description of chosen parameters includes calculations of strain acting during operation, technical and stability parameters, essential for the construction. All calculations were made with regard to valid Czech technical standards and specialized literature which focuses on the construction of cranes and their parts. Finally, the thesis is extended by the required technical drawings.

The main goal of this diploma thesis was to project a design of arch bridge‘s framework over the Svratka river. This single-span bridge has the span of 52,5m. The framework is constructed from a pair of beams, suspended from the pair of beams bent towards each other. The bridge deck is coupled with steel crosspieces. The construction design was executed in computing programme Dlubal RFEM 5.07. The individual components of the framework were assessed in Microsoft Excel. The calculation considered the load of wind and pedestrians’ movement and their effect on the dynamics of the construction. The phases of development were also considered. Assessments of coupled cross-section, main beams of steel construction, tension systems and selected construction joints were executed in a static calculation. Moreover, a design of a bearing and a bridge plug joint. Finally, a drawing documentation and a final report were prepared in regards with the requirements. The construction design and its assessment were executed according to valid standards.

The object of the theoretical part of this diploma thesis is overview of the historical development of reinforced concrete and concrete reinforcements, including the elaboration of a detailed methodology for the assessment of the state of bridge structures. It is applied in practical parts of two bridges independent on each other. There are used the most modern technologies like device Hilti PS1000, profometer PM-630 to diagnose objects and they are completed by chopped probe. It also includes a structural analysis of the load capacity, that concurrently evaluates the quality of the construction.

Dimensionierung und Konstruktion von Bewehrungstextilien für die Anwendung in Textilbeton werden in Abhängigkeit von der resultierenden Last im Bauteil durchgeführt. Um aus der Vielzahl möglicher Varianten von Bewehrungsstrukturen die passenden auszuwählen, wird ein reduziertes Beschreibungsschema zur Auswahl herangezogen. Als Anwendungsbeispiel wird eine komplexe Bewehrungsstruktur beschrieben, die für dünnwandige, selbsttragende Sandwichelemente genutzt wird. Die Sandwichelemente werden als Wandund Dachkonstruktion für ein 20 m² großes modulares Gebäude eingesetzt. Die Bewehrungsstrategie für die Elemente sowie die Herstellungstechnik und Prüfverfahren für die Bewehrung werden beschrieben. Zur Langzeitüberwachung der Sandwichelemente wird ein Monitoring-System verwendet.

Världen har de senaste åren upplevt flera terrorattentat där fordon har använts som vapen för att orsaka skador i folkmassor. Fotgängare kan vara i en utsatt miljö på gångstråk och skydd i form av betonghinder kan användas för att stoppa oönskad trafik på gågator. C3C Engineering AB tillverkar betongblock som antingen kan användas som enskilda element eller byggas ihop likt lego för att skapa murar och barriärer. Betongblocken kan således även användas som skyddsbarriärer vid pågående vägarbeten, för tillfälliga konstruktioner på exempelvis återvinningscentraler eller som stödmurar. C3C tillverkar i så stor utsträckning som möjligt betongblocken av restbetong som blivit över vid gjutning av andra typer av element. Syftet med denna studie var att undersöka betongblocks lastkapacitet med avseende på påkörningslaster från personbilar, lastbilar och gaffeltruckar. Betongblocket var av typen C3Cblock® 1688 med dimensionerna 800 mm x 800 mm x 1600 mm och tillverkades i betongkvalité C20/25. Arbetet undersökte hur olika förstärkningar såsom ingjutna gängstänger samt kontreforer kunde öka blockens kapacitet. Även hur blockens underlag påverkar lastkapaciteten med avseende på glidning undersöktes. Påkörningslaster är dynamiska laster. I detta arbete behandlades samtliga dynamiska laster med hjälp av statiskt ekvivalenta laster. Lastkapaciteten hos blocken med avseende på stjälpning, glidning, dymlingsverkan, skjuvkapacitet i styrkonsoler och moment- och tvärkraftskapacitet jämfördes med rekommenderade värden för påkörningslaster från Eurokod 1 och EKS6. För exceptionella lastfall kan blocken tillåtas att gå sönder, glida eller stjälpa eftersom deras huvudsakliga syfte är att stoppa trafik och skydda människor på gator eller arbetsplatser utmed trafikerade vägar. Beräkningar utfördes med hjälp av MathCad och Excel för att ta fram ett beräkningsdokument samt en tabell med lastkapacitet för samtliga lastfall som undersökts. Resultat från beräkningar för stjälpning och glidning jämfördes med underlag som C3C tillhandahöll. Beräkningar gjordes för enskilda block samt för olika murar med olika utföranden där bland annat höjden på muren och vilken sida av blocken som lasten angrep var parametrar som varierade. Resultatet visade att lastens angreppshöjd hade stor inverkan på murens kapacitet. Lastbilar och gaffeltruckar har högre angreppshöjd än personbilar. För de höga angreppshöjderna kommer stjälpning av muren att bli dimensionerande, jämfört med låga angreppshöjder där glidning inträffar först. Blocken kan tillåtas att gå sönder och därmed är moment- och tvärkraftskapacitet av sekundär betydelse. Styrkonsolernas skjuvkapacitet var stor och kommer därför inte vara dimensionerande. På grund av avgränsningar studerades endast en typ av betongblock. Ingen hänsyn togs till andra laster såsom vind eller snö som även de kommer att påverka en murs kapacitet. Det krävs därför vidare studier för att undersöka hur dessa laster samt hur olika dimensioner påverkar lastkapaciteten hos enskilda block eller murar. Försök kan med fördel utföras för att validera de teoretiska lasterna som beräknats i detta arbete. / Due to an increasing number of acts of terror where vehicles are used as a form of weapon a need to protect pedestrians has arisen. In this study the load capacity of interlocking concrete blocks with a rectangular cross section was examined based on various deformations and collapses. The concrete blocks could be used as protection against collisions such as terrorist attacks with vehicles as well as a barrier between work zones and close by traffic. The purpose of the study was to determine the load capacity in the event of a collision with a car, truck or forklift for different types of walls as well as for single blocks. The concrete blocks in the walls have both been built as Lego as well as stacked parallel on top of each other. The work is based on calculations. The results have been checked against existing documents from C3C Engineering AB. Using MathCad and Excel a document for calculations has been designed. The result from the calculations shows that walls will slide when a load acts at a low height in relation to the ground. The wall will overturn when the load acts at a higher distance from the ground.

This thesis contains diagnostics of a reinforced concrete girder bridge in the municipality of Újezd u Brna. The aim is to conduct an inspection of the bridge, gather quality photo-documentation of defects and failures and design and conduct a diagnostic examination of such extent that would be necessary for judging the load bearing capacity of the bridge. The result of this thesis is the determined load bearing capacity and a proposal of measures required to keep the bridge functional.