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Abstract : Circular reinforced concrete (RC) members are often used in civil engineering structures, for instance, as piers and piles in bridge substructures. Also, their applications are frequently utilized as a fender and piling system for harsh water front and marine environments. Such members are usually reinforced with conventional steel bars and stirrups. Corrosion of steel reinforcement constitutes one of the major problems that shorten the lifetime serviceability and, hence, brittle failure of many concrete structures worldwide. In the last decade, the use of fiber reinforced polymer (FRP) materials has been growing to solve some of these problems and increase the anticipated service life of RC structures, such as bridges, parking garages, tunnels, and marine structures. Recently, the use of FRP bars in soft-eyes, which are openings in retaining walls that will be pierced by tunnel boring machines (TBMs), is gaining popularity in the field of tunnel excavation. In recent years, the shear behavior of RC members reinforced with FRP bars has been the focus of many studies. Accordingly, several codes and design guidelines are available for the design of concrete structures reinforced with FRP bars under shear loads. These codes and design guidelines were developed based on experimental work on rectangular concrete members reinforced with FRP bars and stirrups. Yet, no research seems to have assessed circular concrete members reinforced with FRP bars and spirals under shear loads. In this research study, an experimental program was designed to investigate the shear behavior of circular members reinforced with glass FRP (GFRP) and carbon FRP (CFRP) bars, and spirals. A total of twenty full-scale circular RC specimens, with a total length 3,000 mm and 500 mm in diameter, were fabricated and tested experimentally under shear load. The specimens were divided to five series; series I contains two reference steel-RC specimens with and without spiral reinforcement. Series II contains three specimens internally reinforced with GFRP longitudinal bars and without spiral reinforcement. Series III contains five specimens reinforced with GFRP longitudinal bars and spirals (Type I). Series IV includes six specimens reinforced with GFRP bars and spirals (Type II), while series V includes four specimens totally reinforced with CFRP reinforcement. The experimental tests were performed at the structural laboratory, Faculty of Engineering, University of Sherbrooke. The main objective of testing these specimens is to investigate the behavior of circular concrete members reinforced with GFRP or CFRP longitudinal bars and transverse spirals reinforcement. Several parameters have been studied; type of reinforcement, longitudinal reinforcement ratio, shear reinforcement ratio (spiral diameter and spacing), and shear-span-to-depth ratio. The test results of the tested specimens were presented and discussed in terms of load deflection response, crack patterns and modes of failure, ultimate shear capacities, concrete, longitudinal, and spiral strains, effectiveness of FRP spirals, and beam action versus arch action through four journal papers in this dissertation. In addition, an analytical investigation was conducted to evaluate the validity and accuracy of available FRP shear design equations in codes and design guidelines, and to determine whether certain modifications should be introduced in order to make them suitable for circular concrete members reinforced with FRP bars and spirals. The tested specimens were also analysed using Response 2000 (R2K), which is based on the modified compression field theory (MCFT). Based on the finding of this investigation, the shear capacity of FRP-RC members with circular sections may be determined with the approaches developed for rectangular sections provided that certain modifications are made to take into account the effective shear depth, equivalent breadth, the mechanical properties and geometry of GFRP or CFRP spirals. Furthermore, a new equation was introduced to quantify the spirals contribution (V[subscript s[florin]]) in circular concrete members to account for FRP spiral inclination, curvature, and strength reduction as a result of the stretching process. The proposed equation provided more reasonably accurate predictions. / Résumé : Les éléments circulaires en béton armé sont largement utilisés dans les structures en génie civil, comme par exemple, les pieux et les piles de pont. Également, ils sont très utilisés dans les systèmes de pieux battus dans des environnements agressifs et marines. Ces éléments sont habituellement utilisés avec un renforcement interne en acier. La corrosion de l'acier est un des problèmes majeurs qui diminuent la durée de vie et peuvent même amener la structure à la ruine et ce, partout dans le monde. Dans la dernière décennie, utiliser des polymères renforcés de fibres (PRF) est une bonne solution aux problèmes précédents et augmente la durée de vie des structures en béton armé, comme les ponts, les stationnements, les tunnels et les structures marines. Récemment, l'utilisation des barres de PRF dans les murs-diaphragmes, qui sont des ouvertures dans les murs de soutènement percé avec de la machinerie d'excavation de tunnel, gagne en popularité dans le domaine de l'excavation de tunnel. Depuis quelques années, le comportement en cisaillement des éléments en béton armé de PRF a été étudié dans plusieurs recherches. Par conséquent, les normes et les guides de dimensionnement sont disponibles pour les efforts tranchants. Ils sont développés à partir des expériences en laboratoires sur des éléments rectangulaires. Par contre, aucune recherche a été fait sur les éléments circulaires renforcés de PRF avec des barres et des spirales sous un effort tranchant. Dans ce sujet d'étude, un programme expérimental a été développé pour regarder le comportement en cisaillement des éléments circulaires en béton armé de PRV de verre (PRFV) et de PRF de carbone (PRFC), pour les barres longitudinales ainsi que pour les spirales (transversales). Un total de 20 spécimens circulaire de grandeur réelle, avec comme dimension 3,000 mm de long et 500 mm de diamètre, ont été fabriqués et testés à l'effort tranchant. Les spécimens ont été divisés en cinq séries; la série I contient deux spécimens de références en acier avec et sans renforcement transversal. La série II contient trois spécimens ayant de l'armature longitudinale en PRFV avec et sans renforcement transversal. La série III contient cinq spécimens renforcés de PRFV (Type I) dans le sens longitudinal et transversal. La série IV comprend six spécimens renforcés de PRFV (Type II) dans le sens longitudinal et transversal. Finalement, la série V comprend quatre spécimens totalement renforcés de PRFC. Les essais expérimentaux ont été réalisés dans le laboratoire de structure de la Faculté de génie à l'Université de Sherbrooke. L'objectif principal est de tester ces spécimens pour étudier le comportement des poutres circulaires en béton armé avec des PRFV et PRFC pour le renforcement longitudinal et transversal (spiral). Plusieurs paramètres y sont étudiés : type de renforcement, le taux d'armature longitudinal, le taux d'armature en cisaillement (diamètre et espacement des spires) ainsi que le rapport portée en cisaillement sur la profondeur effective. Les résultats sur les spécimens sont présentés et discutés en terme de la flèche, du réseau de fissuration, du mode de rupture, de la capacité ultime en cisaillement, le béton, la déformation longitudinale et transversale, efficacité des spirales en PRF, l'action de poutre à arche sur quatre articles de journal discutés dans cette dissertation, une étude analytique pour évaluer la validité des équations disponibles dans les codes et les guides de dimensionnement et de déterminer si certaines modifications devraient être faites pour que les sections circulaires avec un renforcement complet avec des spirales en PRF soient mieux adaptées. Les poutres testées ont également été analysées en utilisant Response 2000 (R2K), où il est basé sur la théorie du champ de compression modifiée (TCCM). Basé sur les résultats obtenus, la capacité en cisaillement des éléments circulaires en béton armé de PRF a été déterminé avec l'approche d'une section rectangulaire mais en changeant certains paramètres pour prendre en compte la profondeur effective, la largeur équivalente, des propriétés mécaniques ainsi que la géométrie des PRFV et PRFC pour les spirales. De plus, une nouvelle équation est introduite pour quantifier la contribution des spirales (V[indice inférieur s[florin]]) des éléments circulaires pour prendre en considération l'inclinaison des spires, de la courbure et de la réduction de la résistance suite à l'étirement de la spirale. L'équation proposée permet de prédire raisonnablement la capacité en cisaillement.

The primary objective of this research was to experimentally investigate material and bond properties of three different types of fiber reinforced polymer (FRP) bars, and determine their effect on the design of a bridge deck using FRP bars as the top mat of reinforcement. The properties evaluated include the tensile strength, modulus of elasticity, bond behavior, and maximum bond stress. The experimental program included 47 tensile tests and 42 beam end bond tests performed with FRP bars. Tensile strength of the bars from the tensile testing ranged from 529 MPa to 859 MPa. The average modulus, taken from all the testing, for each type of bar was found to range from 40 GPa to 43.7 GPa. The maximum bond stress from the beam end bond tests ranged from 9.17 MPa to 25 MPa. From the tests, design values were found in areas where the properties investigated were related. These design values include design tensile strength, design modulus of elasticity, bond coefficient for deflection calculations, bond coefficient for crack width calculations, and development length. The results and conclusions address design concerns of the different types of FRP bars as applied in the top mat of reinforcement of a bridge deck. A secondary objective was to evaluate the disparity in results between direct pullout tests, and beam end bond tests. Results from the experimentally performed beam end bond test were compared to previous literature involving the direct pullout tests. Results from the performed beam end bond tests were higher than all of the literature using direct pullout results. No recommendations were given on the disparity between the two test methods. / Master of Science

A substituição do aço pela armadura não metálica objetiva o aumento da durabilidade de estruturas sujeitas à corrosão e a campos eletromagnéticos. Mas, a inserção de um novo material na construção civil demanda especificação de sua composição, comportamento e procedimentos de sua utilização. Este trabalho analisa o comportamento à flexão de vigas de concreto armadas com barras não metálicas. Para esta finalidade foram realizados, uma revisão bibliográfica considerando os trabalhos publicados desde o início das pesquisas até os mais recentes e ensaios dos materiais e de vigas de concreto armado. Os ensaios de determinação das propriedades das barras da armadura não metálica de GFRP (glass fiber polymer – polímero reforçado com fibra de vidro) englobam a determinação do diagrama tensão-deformação e capacidade resistente. As vigas armadas com barras de GFRP foram ensaiadas à flexão em quatro pontos e os resultados comparados com o de uma viga armada com barras de aço CA-50 também ensaiada a flexão. Nos modelos pôde-se perceber a influência das propriedades das barras de GFRP no comportamento geral da estrutura. Por exemplo, as grandes deformações nas barras longitudinais e os deslocamentos dos modelos foram determinados pelo baixo módulo de elasticidade das barras de GFRP. É evidente a necessidade de continuação dos estudos envolvendo barras de GFRP. Estas pesquisas poderão desenvolver meios de se utilizar as propriedades do material em favor do melhor funcionamento da estrutura / Steel reinforcement replacement aims an increase at the durability of structures with corrosion and electrical magnetic problems. But, inserting a new material at the civil construction industry demands specifications of its composition, behavior and procedures for its utilization. This work is a flexural behavior analysis of reinforced concrete beams reinforced with GFRP bars. To make this, a technical literature research was made considering the pioneer until the most recent researches, and components and concrete reinforced beams tests were done. GFRP bars properties tests went from the determination of its strains X stress diagram to its tension resistance. GFRP reinforced beams were submitted to four points flexural tests and the results compared with a CA-50 steel reinforced beam also submitted to the flexural test. The specimens showed the influence of GFRP properties at the behavior of the structure. For example, longitudinal bars large strains and the large displacement of the beam were determined by GFRP bars low longitudinal elastic modulus. Continuing the studies evolving GFRP bars is certainly a need. New researches might be able to design a way to use the composite properties to improve the structure behavior

A substituição do aço pela armadura não metálica objetiva o aumento da durabilidade de estruturas sujeitas à corrosão e a campos eletromagnéticos. Mas, a inserção de um novo material na construção civil demanda especificação de sua composição, comportamento e procedimentos de sua utilização. Este trabalho analisa o comportamento à flexão de vigas de concreto armadas com barras não metálicas. Para esta finalidade foram realizados, uma revisão bibliográfica considerando os trabalhos publicados desde o início das pesquisas até os mais recentes e ensaios dos materiais e de vigas de concreto armado. Os ensaios de determinação das propriedades das barras da armadura não metálica de GFRP (glass fiber polymer – polímero reforçado com fibra de vidro) englobam a determinação do diagrama tensão-deformação e capacidade resistente. As vigas armadas com barras de GFRP foram ensaiadas à flexão em quatro pontos e os resultados comparados com o de uma viga armada com barras de aço CA-50 também ensaiada a flexão. Nos modelos pôde-se perceber a influência das propriedades das barras de GFRP no comportamento geral da estrutura. Por exemplo, as grandes deformações nas barras longitudinais e os deslocamentos dos modelos foram determinados pelo baixo módulo de elasticidade das barras de GFRP. É evidente a necessidade de continuação dos estudos envolvendo barras de GFRP. Estas pesquisas poderão desenvolver meios de se utilizar as propriedades do material em favor do melhor funcionamento da estrutura / Steel reinforcement replacement aims an increase at the durability of structures with corrosion and electrical magnetic problems. But, inserting a new material at the civil construction industry demands specifications of its composition, behavior and procedures for its utilization. This work is a flexural behavior analysis of reinforced concrete beams reinforced with GFRP bars. To make this, a technical literature research was made considering the pioneer until the most recent researches, and components and concrete reinforced beams tests were done. GFRP bars properties tests went from the determination of its strains X stress diagram to its tension resistance. GFRP reinforced beams were submitted to four points flexural tests and the results compared with a CA-50 steel reinforced beam also submitted to the flexural test. The specimens showed the influence of GFRP properties at the behavior of the structure. For example, longitudinal bars large strains and the large displacement of the beam were determined by GFRP bars low longitudinal elastic modulus. Continuing the studies evolving GFRP bars is certainly a need. New researches might be able to design a way to use the composite properties to improve the structure behavior

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly Waggle Kramer / This report discusses the two main types of structural connections used for fiber reinforced polymer (FRP) pultruded shapes, which are mechanical and bonded connections. The most common types of mechanical and bonded connections for FRP pultruded shapes are bolted and adhesively bonded joints respectively, and the advantages and disadvantages of each are discussed. Bolted connections are the most common type of connection used for FRP pultruded shapes and are therefore the focus of this report. Limit states and critical stresses for FRP bolted connections are explained along with the appropriate material properties that are needed to determine them. A simplified mechanics approach to determining the stresses in the FRP material and connection is presented along with a design procedure for FRP connections. A design example is given for a simple beam-to-column shear connection using three materials: FRP pultruded shapes, W-flange steel shapes, and wood sawn lumber in which the beam-to-column shear connection is compared. It is found that the FRP connection is comparable to the steel and wood connections, and all three are able to meet the requirements for the loading conditions given with reasonable results. Possible uses for FRP that would be more ideal than using steel or wood members are presented and areas that still need to be developed or require further research are discussed.

Concrete has many advantages as a low cost and sustainable material. However, more than 5% of the planet’s total carbon emissions are associated with the production of cement, which, in fact, is predominantly due to the large volume of concrete used worldwide. It is known that traditionally designed concrete structures typically use more material than structurally required and, therefore, an important question is whether material demand can be reduced through structural optimisation. A major drawback from optimised design, however, is the cost and complexity of producing conventional rigid moulds. Fabric formwork is emerging as a new method for construction, gaining popularity among architects and engineers for the opportunity to build unique forms and to shape concrete elements efficiently. Porous fabrics, acting as controlled permeability formwork, also have proven effect on the durability characteristics of concrete. While fabric formwork has a profound potential to change the appearance of concrete structures, the shapes cast in fabrics are not defined in advance and have been often created unintentionally. The design of load-bearing reinforced concrete structures, however, requires accurate form-prediction and construction methods for securing steel reinforcement inside flexible fabrics, which presents a number of constructability challenges. For example, cover formers cannot be used to ensure adequate thickness of protective cover, inevitably affecting the acceptance of such structures in practice. This research has demonstrated that non-corrodable FRP reinforcement can be incorporated more easily than steel bars in fabric-formed concrete due to its light weight and flexibility, while it is possible to ensure ductility of such structures through confinement of concrete using FRP helices. A novel splayed anchorage system has been developed to provide end anchorage for optimised sections where standard bends or hooks cannot fit. This work also provides an experimentally verified methodology and guidance for the design and optimisation of fabric-formed elements.

The actual shear capacity of existing concrete structures is often unable to meet current standard requirements. This may be attributable to increased load requirements, inadequate shear provisions in the original design or increased demand in shear capacity owing to flexural strengthening. However, available methods of assessment are often conservative, and the actual strength may be sufficient to sustain the specified assessment load. Therefore, it is important that realistic assessment methods are employed. This research comprises an investigation into the shear capacity of prestressed concrete bridges and into the feasibility of a novel strengthening approach, both through comprehensive laboratory experimentation and theoretical analyses. The laboratory testing indicates that the shear capacity of prestressed concrete bridges, post-tensioned transversely to form a deck, can be significantly greater than suggested by the relevant standards. The strengthening method proposed, namely deep embedment of steel or fibre-reinforced polymer (FRP) bars, is found to be feasible and very effective for reinforced concrete (RC) and prestressed concrete (PSC) beams of any size. Analytical models based on the upper-bound theorem of plasticity theory are successfully developed and applied, resulting in much more realistic predictions than those from current standards and codes when assessing shear capacity. For the strengthened beams, in addition to an upper-bound model, a strengthening design method based on a truss analogy is developed, which can be directly implemented into codes of practice. The analytical methods permit the assessment of existing longitudinally and laterally prestressed concrete bridges for shear capacity in a rational manner, and then to determine the capacity of a practical shear strengthening system if the bridge turns out to actually be understrength. Use of the proposed methodology will allow significant savings, as the costs associated with replacing or strengthening the structure can be avoided or minimised, encouraging a sustainable approach.

The highly competitive nature of the transportation industry has produced significant demand for increased equipment efficiency. This has been manifested in attempts to increase carrying capacity whilst lowering running costs. While these factors remain at the forefront of trailer design, the dependence on steel as the primary material has limited the extent to which these goals are realised. The advantages associated with the use of fibre composite materials in automotive applications have been well documented, demonstrating that the substitution of steel with fibre composite materials greatly increases the scope for tare mass reduction. However, to fully utilise the advantages produced through the use of fibre composites, it is necessary to formulate a design philosophy that incorporates the selection of materials and the definition of acceptable performance of both the material and the trailer. This dissertation addresses this broad subject. Within this greater context, this study addresses the incorporation of fibre composite materials into semi-trailers, with the significant issues being divided into two areas: - The development of a design philosophy, intended specifically to address the application of fibre composites to semi-trailers. - The design, analysis and experimental validation of a new type of fibre composite trailer chassis, utilising the aforementioned design philosophy. This PhD project is a foundational study on the suitability of fibre composite materials in the heavy transportation industry, primarily focusing on a practical assessment of the potential for tare mass reduction. The work presented in this dissertation is seen to provide a basis for fibre composite trailer design, in addition to a foundation upon which further investigation into this field can be made. The major outcomes of this project include, amongst others: - The definition of significant load cases and trailer classifications · The development of a design philosophy suited specifically to FRP semi-trailers - The establishment of selection criteria which identifies appropriate FRP materials for use in this application - The development of a new type of FRP chassis for a flatbed semi-trailer - Validation of the design philosophy through experimental testing - Affirmation of the potential of FRPs in application to flatbed semi-trailers

Fiber reinforced polymer (FRP) deck has some significant advantages compared to concrete deck in use of bridges, such as light self-weight, high stiffness and strength, good durability and easy to install. FRP deck has already been used in some bridge rehabilitation and short span bridges. But for widely used in bridges, FRP deck bridges still need further research. Currently many research efforts focus on the filed tests of FRP deck bridges. Compared to field tests, Finite element analysis also has great advantages, such as low cost and convenient to conduct. Therefore, in this thesis finite element analysis is conducted by ABAQUS on the Boyer Bridge in Pennsylvania. The finite element model is verified by the static field test result. Then a simplified moving truck load is applied on the bridge model in order to analyze the dynamic responses of the FRP deck bridge, including the displacements and stress of each girder at the middle span. The dynamic effect is shown by comparing the dynamic responses and the static responses of the bridge. The connection between the FRP deck and girder is very important to the behavior of the bridge. In this thesis shear studs serve to connect the FRP deck and girder. This thesis also analyzes the effect of shear studs to the dynamic responses of the bridge by changing the number of the shear studs.