This thesis deals with the design and assessment of the load-bearing structure of the lookout tower. The tower is 37.45 m high with the layout in the shape of a regular octagon. The object is located within the city of Zlín. The project is provisionally drawn in two variants. Hand-static calculation, drawings and engineering report is processed only for one variant. The variants differ in the structure of staircase. The thesis is drawn up pursuant to the standards of ČSN EN.

A nonlinear finite element analysis was performed for an existing road bridge in order to see if that could show a higher load bearing capacity, as an alternative to repairing or replacing. The regular linear analysis had shown that the bridge could not take any traffic load due to the effects from large and uneven support settlements. It is a five-span reinforced concrete bridge with a continuous slab on supports made out of rows of columns. The width-to-span ratio was around 1 and the supports were angled up to about 30°, giving rise to a complex three-dimensional behaviour, which was seen and studied in the nonlinear results. Since the bending moment was the limiting factor, the nonlinear analysis focused on that. The direct result was that the load bearing capacity was 730 kN for the traffic vehicle boogie load, B, in the ultimate limit state. This was however only for the load case tested, and several more disadvantageous vehicle positions may exist. Other aspects also became limiting, as the maximum allowed vertical deflection in the serviceability limit state was reached at 457 kN. The most restraining though, was the shear capacity from the linear analysis; 78 kN, since it was not possible to simulate that type of failure with the shell elements used in the nonlinear finite element analysis. The main aim of the thesis was nonetheless reached, since the nonlinear analysis was able to show a significant increase in load bearing capacity.  A comparison was made with the settlements for the nonlinear case, to see how much influence they had on the load bearing capacity for traffic load. This was performed for both the bridge and a simple two-span beam. Both showed that there was no effect on the load bearing capacity in the ultimate limit. One thing to note was that the full settlements were applied, and with no relaxation due to creep.  Another aim of the thesis was to make comments on the practical usability of the nonlinear finite element method in load bearing capacity assessments. A linear analysis was performed before the nonlinear in order to be able to determine the load case to be used in the latter. This worked well, as the strengths of the two methods could then be utilized. Convergence problems were however encountered for the nonlinear when using the regular static solver. Due to this, the dynamic explicit calculation scheme was used instead, treating the case as quasi-static. This managed to produce enough usable results. It was concluded that the nonlinear finite element method is useable for assessment calculations, but that its strengths and weaknesses must be known in order to make it an efficient method.

The global population is estimated to rise by 89 million people annually and for this reason there is a need for more housing and buildings worldwide. As cities grow outwards and buildable land becomes scarce, it is necessary to increase the height of buildings in cities, especially where the height of existing buildings is low. For crowded cities, story extensions are an increasingly popular measure that could meet market’s demand for centrally located homes.The main focus of this study is to clarify how a specific existing building handles the addition of a story. The existing building that was used as a starting point is located in Styrmansgatan in Gävle, the district Brynäs. The building has totally three storiesand is a youth residence where HBS is the property owner. The study presents the approach to validate and simulate the existing building.The method of the work is modelling in StruSoft FEM-Design which is a program used for modelling, analysis and design of load-bearing elements of buildings according to Eurocode. With the help of the program, it is investigated whether the existing building can handle an extension and which reinforcements should be made. It is suitable for all different types of design tasks from the entire stability analysis in a building to individual elements. The work is carried out in 3 steps where first the reference building to be used as a starting point is modelled, analyzed and designed. The next step is to add a story and then analyze any additional measures in connection with the extension of the story. The building must be approved according to standards as a starting point with regard to degree of utilization and deflection. Then, a comparison is made between the existing building structure and the superstructure with respect to degree of utilization, deflection, stress, and the base reaction.Results obtained from this study show that if an extension is to be possible, reinforcement solutions should take place for building elements that receive an unacceptable degree of utilization. The reinforcement solutions are resulted with the help of beams, columns, wind brace and changed reinforcement contents in reinforced concrete elements for the load-bearing structure. The study concludes that the story extension is possible with added reinforcement measures / Den globala befolkningsmängden beräknas stiga med 89 miljoner människor årligen och av den anledningen finns det ett behov av fler bostäder och byggnader över hela världen. När städer växer utåt och expanderar blir byggbar mark en bristvara, där kan påbyggnad vertikalt vara ett alternativ då man ökar höjden på byggnader. För trånga städer är våningspåbyggnader en alltmer populär åtgärd som skulle kunna möta marknadens efterfrågan av centralt placerade bostäder. Huvudfokus i denna studie är att klargöra hur en specifik befintlig byggnad klarar påbyggnad av ett våningsplan. Den befintliga byggnaden som användes som utgångspunkt ligger på Styrmansgatan i Gävle, stadsdelen Brynäs. Byggnaden har totalt tre våningar och är ett ungdomsboende där HSB står som fastighetsägare. Studien presenterar tillvägagångssättet för validering och simulering av en befintlig byggnad.Arbetet utfördes med StruSoft FEM-Design som används för modellering, analys och design för bärande element i byggnader baserade på Eurokod. Med hjälp utav StruSoftFEM-Design ska det undersökas om den befintliga byggnaden klarar av en utökning och huruvida vilka förstärkningar som eventuellt bör ske. Den passar för alla olika typer utav konstruktionsuppgifter från hela stabilitetsanalysen i en byggnad till enskilda element. Arbetet kommer genomföras i 3 steg där först den referensbyggnad som skall användas som utgångsläge modelleras, analyseras och designas. Nästa steg är att lägga till ett våningsplan för att sedan analysera eventuella tilläggsåtgärder i samband med utökning av ett våningsplan. Byggnaden skall vara godkänd enligt standarder som utgångspunkt med avseende på utnyttjandegrad och nedböjning. Därefter sker det en jämförelse mellan den befintliga bygganden och påbyggnaden med avseende på utnyttjandegrad, nedböjning, spänning och grundreaktionen.Resultat som har erhållits från denna studie påvisade att om en påbyggnad ska vara möjlig bör förstärkningslösningar äga rum för byggnadselement som fick en oacceptabel utnyttjandegrad. Förstärkningslösningen resulterade med hjälp av balkar, pelare, vindstage och ändrat armeringsinnehåll för armerad betong element för den bärande konstruktionen. Studiens slutsats är att våningspåbyggnad är möjlig vid tillagda förstärkningsåtgärder.

A nonlinear finite element analysis was performed for an existing road bridge in order to see if that could show a higher load bearing capacity, as an alternative to repairing or replacing. The regular linear analysis had shown that the bridge could not take any traffic load due to the effects from large and uneven support settlements. It is a five-span reinforced concrete bridge with a continuous slab on supports made out of rows of columns. The width-to-span ratio was around 1 and the supports were angled up to about 30°, giving rise to a complex three-dimensional behaviour, which was seen and studied in the nonlinear results. Since the bending moment was the limiting factor, the nonlinear analysis focused on that. The direct result was that the load bearing capacity was 730 kN for the traffic vehicle boogie load, B, in the ultimate limit state. This was however only for the load case tested, and several more disadvantageous vehicle positions may exist. Other aspects also became limiting, as the maximum allowed vertical deflection in the serviceability limit state was reached at 457 kN. The most restraining though, was the shear capacity from the linear analysis; 78 kN, since it was not possible to simulate that type of failure with the shell elements used in the nonlinear finite element analysis. The main aim of the thesis was nonetheless reached, since the nonlinear analysis was able to show a significant increase in load bearing capacity. A comparison was made with the settlements for the nonlinear case, to see how much influence they had on the load bearing capacity for traffic load. This was performed for both the bridge and a simple two-span beam. Both showed that there was no effect on the load bearing capacity in the ultimate limit. One thing to note was that the full settlements were applied, and with no relaxation due to creep. Another aim of the thesis was to make comments on the practical usability of the nonlinear finite element method in load bearing capacity assessments. A linear analysis was performed before the nonlinear in order to be able to determine the load case to be used in the latter. This worked well, as the strengths of the two methods could then be utilized. Convergence problems were however encountered for the nonlinear when using the regular static solver. Due to this, the dynamic explicit calculation scheme was used instead, treating the case as quasi-static. This managed to produce enough usable results. It was concluded that the nonlinear finite element method is useable for assessment calculations, but that its strengths and weaknesses must be known in order to make it an efficient method.

Über 60 % der Aufträge der Bauindustrie werden heute im Bestand umgesetzt. Bei Umbauten oder Aufstockungen stellt sich für den Tragwerksplaner dabei wiederkehrend die Frage nach der Tragsicherheit der Baukonstruktionen für die aktuellen Lastansätze. Besondere Herausforderungen sind historische Bauwerke, die auf der Grundlage traditioneller, baumeisterlicher Erfahrungen mit zeitgenössisch verfügbaren Materialien errichtet worden sind. Sie lassen sich mangels zuverlässiger Daten über die Baustoffe und den Lastabtrag nur selten rechnerisch zutreffend beurteilen. Dieser Beitrag soll zurückblicken auf die vergangenen 15 Jahre, in denen wir über 180 Decken in fast 60 Bauwerken durch Belastungsversuche getestet haben. Dabei möchten wir von unseren Erfahrungen berichten, Besonderheiten herausheben und grundsätzlich das Potential sowie die Grenzen der experimentellen Tragsicherheitsanalyse bewerten.

No description available.

Natural composites, in particular nacre, often combine high strength and toughness thanks to highly ordered architectures and controlled geometries of the reinforcement components. However, combining strength, toughness and resorbability in synthetic materials remains a challenge in particular in the field of bone graft substitutes. In the present study, calcium phosphate-(CaP-)based materials with designed architectures inspired from natural composite materials were achieved. CaP platelets obtained by precipitation in organic medium were first aligned in chitosan matrices by solvent casting in ambient conditions. Efficient strengthening was obtained with 15 vol-% ceramic, reaching cortical bone strength (150 MPa) and preserving good ductility (5 % deformation). In a weak magnetic field, high spatial arrangement without percolation was maintained up to 20 vol-%. With directional freezing, good alignment of the platelets could be pushed up to 50 vol-%. In parallel, in situ recrystallization of CaP blocks in hydrothermal conditions led to hierarchical structures. The strength and the work-of-fracture were enhanced (300%) thanks to a change of failure mode.

Baigiamajame magistro darbe nagrinėjami galimi prekybos ir pramogų centro perdangos ir ledo arenos denginio pagrindinių laikančiųjų konstrukcijų variantai, įvertinami jų techniniai– ekonominiai rodikliai, parenkamas racionalus konstrukcijų variantas tolesniam pastato projektavimui. Nagrinėjamas gelžbetoninės ledo arenos denginio arkos patikimumas, išskiriami rodikliai, darantys didžiausią įtaką konstrukcijos patikimumui, atliekama konstrukcijos parametrinė analizė. Pateikiamos baigiamojo darbo išvados. Projektuojama briaunotoji TT tipo denginio plokštė, gelžbetoninė dviejų lankstų denginio arka su iš anksto įtempta styga, kolona ir polinis pamatas, parengiami šių konstrukcijų darbo brėžiniai. Darbą sudaro 11 dalių: įvadas, aiškinamasis raštas, techninė-ekonominė, konstrukcijų projektavimo ir patikimumo analizės dalys, išvados, literatūros sąrašas. Darbo apimtis – 149 p. teksto be priedų, 43 iliustr., 27 lent., 34 bibliografiniai šaltiniai, 9 A1 lapai brėžinių. Atskirai pridedami darbo priedai. / This MA thesis focuses on the possible versions of floors in a Shopping and Entertainment Centre as well as the roof load-bearing constructions of an Ice Arena. Their technical and economic parameters are evaluated and a rational construction option for the further building design is selected. This thesis analyses the reliability of the reinforced concrete arch in the Ice Arena, and the parameters that have the biggest influence on the reliability of the construction are singled out. The parameter analysis of the construction is presented. The thesis ends with concluding remarks. The design features a double tee-type roof slab, a reinforced concrete two-hinged arch with a pre-stressed tie, a column and a pile foundation. The working drawings of the above-mentioned constructions are drafted. The thesis consists of 11 parts: the introduction, the expository letter, the technological-economic part, the parts dealing with the construction design and reliability analysis, the conclusions, the bibliography, etc. The scope of the thesis is as follows: 149 pages of text without annexes, 43 figures, 27 tables, 34 bibliographical sources and 9 A1-size pages of drawings. There are annexes attached to the thesis.

Atualmente, muitas empresas de construção civil não acompanham o avanço tecnológico, preferindo utilizar sistemas convencionais em vez de investir em novas soluções. Além disso, há sérios problemas com mão de obra, que estão cada vez mais presentes na sociedade. Este trabalho apresenta o projeto de um edifício com elementos pré-moldados de Concreto Leve com pérolas de EPS, considerando lajes prontas maciças e paredes portantes, executadas com esse tipo de material. A princípio, foram considerados os estados limites últimos e de serviço para os elementos da estrutura, utilizando os modelos clássicos de análise estrutural. Para modelagem do edifício, foi utilizado o programa comercial SAP2000. Quanto aos procedimentos para dimensionamento das peças, foram preparadas planilhas do Excel, enquanto o detalhamento foi realizado por meio do AutoCAD. Definido o projeto estrutural, foram considerados aspectos construtivos na fábrica e na obra, levando em conta os custos de produção e de transporte, além de apresentar as vantagens que esse sistema construtivo pode proporcionar. Esses custos foram considerados para as lajes prontas maciças e para as paredes pré-moldadas. Mesmo levando em conta apenas os custos de produção e de transporte, o Concreto Leve com EPS foi comparado com o Concreto Autoadensável, o que permitiu visualizar as vantagens do primeiro, quando for considerado o custo global do empreendimento. / Currently, many construction companies do not follow the technological advances, preferring to use conventional systems rather than investing in new solutions. Moreover, there are serious problems with manpower, which are increasingly present in society. This work presents the design of a building with precast elements of lightweight concrete with EPS beads, considering solid slabs ready to use and load bearing walls, made with this type of material. As a rule, the ultimate limit states and serviceability were considered for the elements of the structure, using classical models of structural analysis. For modelling the building, the commercial software SAP2000 was used. Regarding the procedures for dimensioning of the pieces, Excel spreadsheets were prepared, while the detailing was carried out by means of the AutoCAD. Defined structural design, construction aspects were considered in the factory and in the work, taking into account costs of production and transportation, besides presenting the advantages that this constructive system can provide. These costs were considered for the solid slabs ready to use and for the precast walls. Even taking into account only the cost of production and transportation, the Lightweight Concrete with EPS was compared with Self-compacting Concrete, allowing visualize the advantages of the former when considering the overall cost of the project.

Glasträger sind in einer auf Transparenz ausgerichteten Bauweise zunehmend gefragt. Üblicherweise bestehen diese lastabtragenden Elemente aus mehreren Glasscheiben, verbunden mit Polyvinylbutyral-Folie (PVB-Folie), und gleichen in ihrem Aufbau somit Verbund-Sicherheitsglas (VSG). VSG-Träger besitzen bei vollständigem Glasbruch keine Resttragfähigkeit und werden daher in Dicke und Aufbau mit dem Ziel ausgelegt, vollständigen Glasbruch zu vermeiden. Hybride Glasträger kombinieren in der Regel Glas mit einem duktilen Material und besitzen im Falle des vollständigen Glasbruchs ein duktiles Versagensverhalten. Sie stellen damit eine vielversprechende Option zur Erfüllung des geforderten Sicherheitsniveaus bei Glasträgern dar. Die in der vorliegenden Arbeit betrachteten hybriden Träger entstehen durch die flächige Verklebung von Glas- und transparenten Kunststoffscheiben mit einem ebenfalls transparenten Klebstoff. Bei vollständigem Glasbruch stellt sich ein Tragverhalten ein, bei dem infolge des Klebstoffverbunds der Kunststoff die Zugspannungen und das gebrochene Glas weiterhin Druckspannungen aufnimmt. Die erste Auswahl von Klebstoff und Kunststoff basiert auf Voruntersuchungen an kleinformatigen Prüfkörpern. Die erforderliche Kantenqualität von Floatglas wurde anhand von Vierpunkt-Biegeuntersuchungen bestimmt. Zur weiteren Beurteilung der Eignung des Klebstoffs dienen Klimawechseltests an kleinformatigen Hybridbauteilen, da zwischen Glas und Kunststoff deutliche Unterschiede in der Temperaturausdehnung vorliegen. Aufbauend auf den durchgeführten Untersuchungen wurden das Kunststoffmaterial Polycarbonat und ein niedrigviskoser UV- und strahlungshärtender Acrylatklebstoff, der im ausgehärteten Zustand über hohe Nachgiebigkeit verfügt, für die weiteren mechanischen Untersuchungen an Prüfkörpern im Bauteilformat ausgewählt. Kurzzeitversuche mit kraftgesteuerter Belastungsaufbringung und unter Variation von Polycarbonatdicke, Trägerhöhe und Glasart geben Aufschluss über das Trag- und Resttragfähigkeitsverhalten. Sie stellen die prinzipielle Wirkweise der Hybridträger vor und nach Bruch dar. Vergleichende Versuche an VSG-Trägern demonstrieren die fehlende Resttragfähigkeit dieser Elemente. Belastungsversuche an reinen Polycarbonatscheiben verdeutlichen die Notwendigkeit der Stabilisierung der Hybridträger durch das gebrochene Glas. Langzeitversuche fanden bei statischer Belastung der intakten und gebrochenen Hybridträger statt. Lasthöhe und Belastungsdauer der gebrochenen Träger orientieren sich an realistischen Einsatzbedingungen. Die Versuche zeigen die Unterschiede bei der Entwicklung des Bruchbilds aufgrund der geringeren Last und ermöglichen die Untersuchung des Resttragfähigkeitsverhaltens unter Dauerlast sowie des Ablaufs und der Hintergründe des Trägerversagens. Aufbauend auf den durchgeführten Versuchen erfolgt eine Einteilung der unterschiedlichen Trägerzustände in drei Stadien mit Angaben zu einer einfachen analytischen Betrachtung. Die Diskussion der erhaltenen Ergebnisse sowie ein Ausblick auf weiteren Untersuchungsbedarf schließen die Arbeit ab. / In transparency-oriented architecture, glass beams are increasingly in demand. These load-bearing elements usually consist of multiple glass panes, bonded with polyvinyl butyral foil (PVB foil), and are comparable to laminated safety glass. These glass beams do not assure any level of post-breakage performance after complete glass breakage. Therefore glass thickness and assembly of the beams are chosen with the objective of avoiding complete glass breakage at all costs. Hybrid glass beams typically combine glass with a ductile material and offer a ductile failure mode in case of complete glass breakage. For this reason they represent a promising solution to meet the required safety levels for glass beams. This study deals with hybrid glass beams which are made by bonding panes of glass and transparent plastics using a transparent adhesive. In case of complete glass breakage the plastic material, which is connected to the glass by the adhesive bond, bears the tensile stress whereas the glass is still able to carry the compressive stress. The pre-selection of plastic and adhesive is based on preliminary tests on small specimens. The required quality of the edges of annealed glass was determined by specific four-point bending tests. Because of the considerable difference in thermal expansion between glass and plastics, alternating climate tests were executed on small hybrid components to further evaluate the suitability of the adhesive. Based on the research conducted, the plastic material polycarbonate and a UV- and light-curing acrylate adhesive, which shows a very flexible behavior when hardened, were chosen for further mechanical tests on larger specimens. Short-term tests with constantly increasing load and varying polycarbonate thickness, beam height and glass type provide information on the load-bearing capacity before and the residual load-bearing capacity after glass breakage of the hybrid beams. Comparative tests on laminated glass beams demonstrate the missing residual load-bearing capacity of these components. Loading tests on polycarbonate panes illustrate the need for stabilization of the hybrid beams by the broken glass. Long-term tests were executed by static loading of the intact and broken hybrid beams. The load level and the load duration of the broken beams are based on realistic working conditions. The tests show the difference in the development of the fracture pattern resulting of the lower load and allow the examination of the residual load-bearing capacity at continuous load as well as the process and the reasons behind the beam failure. Based on the tests conducted, three different states of the hybrid beams are categorized and detailed for their easy analytical approach. A discussion of the obtained results and an outlook on further needed research complete the study.