Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Different types of live loading due to traffic may act on bridges. The focus of this study is on normal traffic loading according to the South African specification of TMH7. Heavy vehicles are not included in normal traffic loading. TMH7 represents the code of practice for the design of highway bridges and culverts in South Africa. The aim of the study is to provide an insight into the flexural analysis of skew bridges, under the effects of normal traffic loading. The need for the study arose since the specification of TMH7 does not explicitly specify application patterns for normal traffic loading. Only the intensity of normal traffic loading is specified and it should be applied to yield the most adverse effects. For these reasons, a set of so-called standard application patterns are investigated and developed through the course of this study. The envelope of the values from the standard application patterns are compared to the most adverse application pattern for flexural effects in certain design regions of the bridge deck. Flexure, as in the context of this study, translates into the bending and twisting of the bridge deck under loads. A number of numerical experiments are performed for typical single span and multi-span continuous carriageways, where the standard application patterns are compared to the most adverse application patterns. The results from the numerical experiments are documented and compared as the angle of skew of the bridge deck increases in plan-view. For this purpose, the development of effective and specialized software was necessary. It was found that the set of standard application patterns can be used as a preliminary approximation for the most adverse effects of normal traffic loading, for specific flexural resultants in certain design regions of a bridge deck. However, for a large number of secondary flexural effects, the set of standard application patterns did not represent a good approximation for the most adverse values. / AFRIKAANSE OPSOMMING: Verskillende tipes lewendige belasting, as gevolg van verkeer, kan op brûe inwerk. Die fokus van die studie is op normale verkeers-belasting volgens die Suid-Afrikaanse spesifikasie van TMH7. Swaar-voertuie word nie ingesluit by normale verkeers-belasting nie. TMH7 verteenwoordig die kode vir die ontwerp van padbrûe en duikers in Suid-Afrika. Die doel van die studie is om insig te verskaf in die buig-analise van skewe brûe, as gevolg van die werking van normale verkeers-belasting. Die rede vir hierdie studie ontstaan aangesien die spesifikasie van TMH7 nie eksplisiet aanwendingspatrone vir normale verkeers-belasting voorskryf nie. Slegs die intensiteit van normale verkeersbelasting word voorgeskryf en dit moet aangewend word om die negatiefste effekte te verkry. Vir hierdie redes word 'n versameling van sogenaamde standaard aanwendings-patrone deur die loop van die studie ondersoek en ontwikkel. Die omhullings-kurwe van die waardes wat deur die standaard patrone gelewer word, word vergelyk met die waarde van die aanwendings-patroon wat die negatiefste buig-effek in sekere ontwerp-areas van die brugdek veroorsaak. Buig-effekte, soos van toepassing op hierdie studie, verwys na buig en wring van die brugdek as gevolg van belastings. 'n Aantal numeriese eksperimente, vir enkel-span sowel as multi-span deurlopende brugdekke, word uitgevoer en die standaard aanwendings-patrone word vergelyk met die aanwendings-patrone wat die negatiefste waardes lewer. Die resultate van die numeriese eksperimente word gedokumenteer en vergelyk soos die hoek van skeefheid van die brugdek in plan-aansig toeneem. Vir hierdie doel is die ontwikkeling van effektiewe en gespesialiseerde sagteware dus nodig. Daar is gevind dat die standaard aanwendings-patrone, vir spesifieke buig-resultante in sekere ontwerp-areas van die brugdek, as 'n voorlopige benadering vir die negatiefste effekte van normale verkeers-belasting gebruik kan word. Dit was egter verder gevind dat vir 'n groot aantal sekondêre buig-effkte, die versameling standaard aanwendings-patrone nie as 'n goeie benadering vir die negatiefste waardes dien nie.

High performance concrete (HPC) provides a long lasting, durable concrete that is typically used in bridge decks due to its low permeability, high abrasion resistance, freeze-thaw resistance and strength. However, this type of concrete is highly susceptible to the deleterious effects of both autogenous and drying shrinkage. Both types of shrinkage occur when water leaves small pores , (< 50 nm) in the paste matrix to aid in hydration or is lost to the surrounding environment. Autogenous deformation (self-desiccation) occurs as the internal relative humidity decreases due to hydration of the cementitious material. Drying (and subsequent shrinkage) occurs when water is lost to the environment and continues until the internal relative humidity is equivalent to the ambient relative humidity. Typically, the magnitude of autogenous shrinkage is less than that of drying shrinkage. These two types of shrinkage do not act independently, and the total shrinkage is the aggregation of the two shrinkage mechanisms. It is imperative to minimize the amount of shrinkage in restrained members, such as bridge decks, to reduce the cracking potential. Various methods have been researched to minimize both types of shrinkage. Two methods to that have been reported to reduce shrinkage were selected for further research; internal curing using pre-soaked lightweight fine aggregate (LWFA) and shrinkage reducing admixtures (SRAs). The purpose of this study was to determine the long-term drying shrinkage performance of these two methods while reducing the external curing duration of 14 days for new bridge deck construction as specified by the Oregon Department of Transportation. In addition to monitoring drying shrinkage, durability testing was performed on concrete specimens to ensure these shrinkage mitigation methods performed at levels similar to concrete with the current mixture design. Freeze-thaw testing, permeability testing and restrained drying shrinkage testing were conducted. It was concluded that the combination of SRAs and pre-soaked LWFA was the most effective method to reduce longterm drying shrinkage for all curing durations (1, 7, and 14 day). Additionally, for durability testing, it was found that the use of SRAs performed the best in freeze-thaw testing, chloride permeability and restrained shrinkage. / Graduation date: 2012

O tabuleiro laminado protendido é uma composição de peças interligadas por uma tensão de compressão aplicada perpendicularmente às lâminas de madeira. Para aplicar tal tensão, são usados elementos de aço tensionados e a cordoalha engraxada aparece no cenário atual como um material econômico para tabuleiros laminados protendidos, em substituição às barras dywidag, que são comumente utilizadas neste tipo de estrutura em outros países. O funcionamento mecânico do tabuleiro é caracterizado como uma placa ortotrópica, e este trabalho visou determinar as relações entre as constantes elásticas do tabuleiro com a utilização da cordoalha engraxada. Foram analisadas também as perdas de protensão ocorridas ao longo do tempo, causadas pela fluência e relaxação dos materiais e, a partir dos resultados, foi proposta uma equação para determinação teórica da perda de protensão nos tabuleiros. O estudo experimental foi realizado em um modelo em escala reduzida construído no LaMEM (Laboratório de Madeiras e Estruturas de Madeira) para determinar as constantes elásticas e as perdas de protensão. Ao fim do trabalho são apresentados os resultados e comparações com estudos anteriores; também foi confeccionado um Manual de Boa Execução para Tabuleiros Laminados Protendidos de Madeira com Cordoalha engraxada. / The stress-laminated bridge deck is a composition of parts, interconnected by compression stress, perpendicularly applied to the wood laminate. In order to apply such stress, stressed steel elements are used, as well as the greased wire rope, which comes along in the current scenario as an economic material for stress-laminated bridge decks, replacing the dywidag bars, commonly used in this sort of structure in other countries. This bridge deck mechanic function is characterized as an orthotropic plate, and this paper aimed at determining the relation among the decks elastic constants with the greased wire rope. Another analyzed point is the stress loss occurred through time, caused by material creep and relaxation, and, through the results, an equation for the decks stress loss theoretical determination was proposed. The experimental study was developed in a reduced scale built in LaMEM (Laboratório de Madeiras e Estruturas de Madeira) to determine the elastic constants and the stress loss. The results and comparisons with previous studies are presented by the end of this paper; In addition, a handbook of Proper Execution for Stress-laminated Wood Bridge Decks with Greased Wire Rope was developed.

O tabuleiro laminado protendido é uma composição de peças interligadas por uma tensão de compressão aplicada perpendicularmente às lâminas de madeira. Para aplicar tal tensão, são usados elementos de aço tensionados e a cordoalha engraxada aparece no cenário atual como um material econômico para tabuleiros laminados protendidos, em substituição às barras dywidag, que são comumente utilizadas neste tipo de estrutura em outros países. O funcionamento mecânico do tabuleiro é caracterizado como uma placa ortotrópica, e este trabalho visou determinar as relações entre as constantes elásticas do tabuleiro com a utilização da cordoalha engraxada. Foram analisadas também as perdas de protensão ocorridas ao longo do tempo, causadas pela fluência e relaxação dos materiais e, a partir dos resultados, foi proposta uma equação para determinação teórica da perda de protensão nos tabuleiros. O estudo experimental foi realizado em um modelo em escala reduzida construído no LaMEM (Laboratório de Madeiras e Estruturas de Madeira) para determinar as constantes elásticas e as perdas de protensão. Ao fim do trabalho são apresentados os resultados e comparações com estudos anteriores; também foi confeccionado um Manual de Boa Execução para Tabuleiros Laminados Protendidos de Madeira com Cordoalha engraxada. / The stress-laminated bridge deck is a composition of parts, interconnected by compression stress, perpendicularly applied to the wood laminate. In order to apply such stress, stressed steel elements are used, as well as the greased wire rope, which comes along in the current scenario as an economic material for stress-laminated bridge decks, replacing the dywidag bars, commonly used in this sort of structure in other countries. This bridge deck mechanic function is characterized as an orthotropic plate, and this paper aimed at determining the relation among the decks elastic constants with the greased wire rope. Another analyzed point is the stress loss occurred through time, caused by material creep and relaxation, and, through the results, an equation for the decks stress loss theoretical determination was proposed. The experimental study was developed in a reduced scale built in LaMEM (Laboratório de Madeiras e Estruturas de Madeira) to determine the elastic constants and the stress loss. The results and comparisons with previous studies are presented by the end of this paper; In addition, a handbook of Proper Execution for Stress-laminated Wood Bridge Decks with Greased Wire Rope was developed.

L'avancée de la technologie des PRF a suscité l'intérêt de l'introduction de nouvelles fibres, comme la fibre de basalte, qui a un potentiel d'offrir une solution efficace, lorsqu’utilisée dans les structures en béton, soit sur la résistance à la corrosion, la durabilité et la rentabilité. En outre, les codes et les guides disponibles, ne fournissent pas de recommandations pour l'utilisation de barres en PRFB puisque les recherches passées dans ce domaine sont limitées. Donc, des travaux de recherche sont nécessaires pour caractériser et comprendre le comportement des barres de PRFB dans les éléments en béton armé. En conséquence, les objectifs principaux sont d'évaluer les caractéristiques à court et long terme des barres de PRFB nouvellement développées, ainsi que d'évaluer les performances structurales de ces nouvelles barres comme renforcement interne dans les poutres et les dalles de pont et d'introduire ce nouveau renforcement dans les codes et les guides de dimensionnement. Les tests expérimentaux ont été faits en trois parties. La première partie porte sur le développement de trois nouvelles barres et tendons en PRFB pour déterminer leurs propriétés physiques et mécaniques. Les performances à long terme et de durabilité ont été réalisées en conditionnant les barres de PRFB dans une solution alcaline simulant les conditions humides dans le béton pour déterminer la compatibilité comme renforcement interne dans les éléments en béton. Par la suite, les propriétés ont été déterminées et comparées avec des spécimens non conditionnés (référence). La seconde partie a porté sur sept dalles de pont en béton armé grandeur réelle avec les bords restreints, simulant les tabliers de pont les plus utilisés en Amérique du Nord, pour évaluer la performance des dalles renforcées de PRFB et d'acier. Les dalles mesurent 3000 mm de long × 2500 mm de large × 200 mm d'épaisseur. Les dalles ont été testées jusqu'à la rupture sous une charge concentrée au centre de celles-ci simulant l'empreinte d'une roue d'un camion. Les capacités en poinçonnement sont prédites en utilisant les exigences réglementaires disponibles, et sont comparées aux résultats expérimentaux. La troisième partie de cette étude portait sur les essais de 14 poutres en béton de 3100 mm de long × 200 mm de large × 300 mm de profond pour examiner le comportement en flexion et les performances en service des barres de PRFB avec deux états de surfaces: fini sablé et crénelé. Les poutres ont été testées en flexion en quatre points avec une portée libre de 2700 mm jusqu'à la rupture. Les résultats sont introduits et discutés en terme : du comportement de la fissuration, des flèches, de la capacité en flexion et des modes de ruptures. De plus, le coefficient d'adhérence (kb) des barres de PRFB est déterminé et comparé avec les recommandations des codes et guides actuels. Les résultats sont introduits et discutés en terme : du comportement de la fissuration, des flèches, de la capacité en flexion et des modes de ruptures. De plus, le coefficient d'adhérence des barres de PRFB est déterminé et comparé avec les recommandations des codes et guides actuels. Les résultats de l'étude concluent sur la viables pour la production des barres de PRFB pour respecter les exigences des codes actuelles. Également, les résultats d'essai indiquent que les barres de PRFB ont de bonnes propriétés mécaniques et peuvent être placées dans la même catégorie que les barres de PRFV, soit grade III. De plus, le comportement des poutres et des dalles de pont renforcées de PRFB est similaire que pour un renforcement en PRFV et PRFC et les exigences réglementaires sont applicables pour les barres de PRFB. / Abstract: The advances in fiber-reinforced-polymer (FRP) technology have spurred interest in introducing new fibers, such as basalt FRP (BFRP), which has the potential to offer an efficient solution when implemented in concrete structure, such as corrosion resistant, durable and cost-effective. Furthermore, the available design codes and guides do not provide any recommendations for the use of BFRP bars since fundamental studies and relevant applications are still limited. Therefore, investigations are needed to characterize and understand the behavior of BFRP bars in concrete members. Consequently, the main objectives of this experimental investigation are to evaluate the short- and long-term characteristics of newly developed BFRP bars, as well as evaluate the structural performance of these new bars as internal reinforcement for concrete beams and bridge-deck slabs to introduce these new reinforcing bars to the design codes and guides. The experimental tests were completed through three parts. The first part was conducted on three newly developed BFRP bars and tendons to investigate their physical and mechanical properties. Durability and long-term performance were assessed by conditioning the BFRP bars in an alkaline solution simulating the moist concrete environment to determine their suitability as internal reinforcement for concrete elements. Thereafter, the properties were assessed and compared with the unconditioned (reference) values. The second part of this study was conducted on seven full-scale edge-restrained concrete bridge-deck slabs simulating actual slab-on-girder bridge-deck that is commonly used in North America to evaluate the performance of concrete bridge-deck slabs reinforced with BFRP and steel bars. The deck slabs measured 3000 mm long × 2500 mm wide × 200 mm deep. The slabs were tested up to failure under single concentrated load acting on the center of each slab simulating the footprint of sustained truck wheel load. The punching shear capacities were predicted using the available provisions, and compared with the experimental results. The third part of this study included testing of fourteen concrete beams of 3100 mm long × 200 mm wide × 300 mm deep to investigate the flexural behavior and serviceability performance of sand-coated and ribbed BFRP bars in concrete beams. The beams were tested under four-point bending over a clear span of 2700 mm until failure. The results are introduced and discussed in terms of cracking behavior, deflection, flexure capacity, and failure modes. In addition, the bond-dependent coefficient (kb) of the BFRP bars was determined and compared with the recommendations of the current FRP design codes and guides. The findings of this study concluded the feasibility of producing BFRP bars meet the requirements of the current FRP standards. Also, the test results revealed that the BFRP bars had good mechanical behavior and could be placed in the same category as grade II and grade III GFRP bars. Moreover, the behavior of the concrete bridge-deck slabs and beams reinforced with BFRP bars was quite similar to the counterparts reinforced with glass- and carbon-FRP bars and the available FRP provisions are applicable for BFRP bars. The beam test results yielded an average bond-dependent coefficient (kb) of 0.76±0.03 and 0.83±0.03 for the sand-coated and ribbed BFRP bars, respectively.

This master thesis content is alternative design of one span single-railed steel bridge. The bridge is located in km 44,179 on the track Jaroměř - Dvůr Králové. Crossing barrier is roadway I/33. The teoretical distance between supports is 42 m. Main bearing structure is designed as Langer beam. Structure consist of beams, arcs, suspenders, bridge deck with longitudinal and transversal bracings. Elements of the structure are made out of steel S355J2+N, S235J2+N, S355NL. The bridge is designed according to current standards ČSN EN.

This master' thesis deal with the desiggning of steel bearing structure of road bridge with span of 48,5m with lower bridge deck, which cross local road over the river Thaya in the town Znojmo. Three variants have been designed of arched bridge. The most economical variant was prepared in detail and wascarried out static assessment of individual elements and selected details. In detail solved variant is the bridge with free staing arches and lower bredge deck with composite crosspiece. The span of bridge is 48,5m, width of bridge is 11,5meters, free width of main trafic area 6,5m. Camber of bridge 8,0m

The diploma thesis is focused on a design and appraisal of a steel load bearing construction of footbridge. The footbridge builds a new bridge across the river Ostravice in Sviadnov at Frýdek-Místek. The main subject of the diploma thesis was preparation of three variants for the footbridge. All variants were evaluated and the best one was elaborated in depth. It is a footbridge with a total span of 57 metres with a load bearing construction created two arches bent down to each orther. There is an orthotropic bridge deck with main outer lenghthways girders on the arches.

The aim of this thesis is the design of curved footbridge across the river Bečva. Curved footbridge consists of a supporting steel arch, which brings the steel struts to the steel arch under the concrete deck. The steel arch with crosspieces is coupled with concrete deck using the coupling pins. The deck is formed from reinforced concrete. Structural model is carried out in a computer program ANSYS. The structural design is handled in accordance with applicable European standards. The design considers pedestrians load and temperature effects.

The thesis deals with the variant design of the steel structure of single-track railway bridge on the line Tišnov – Nové Město na Moravě. The task is bridging the local road by a bridge structure with one field. Length of the bridge is 40 m.