This paper is concerned with the behaviour of beam ¿ column connections of steel ¿ concrete composite beams with precast hollow core slabs. Experiments were carried out to investigate the joint rotation characteristics and ultimate moment capacity of these connections. Details of the test specimens, instrumentation, test set-up and test procedures are described. Results obtained for the connection moment capacity, rotation capacity and failure modes are presented. It is found that through proper design and detailing, these simple steel connections display the characteristics of a semi-rigid connection with very little extra cost.

No abstract is provided. / Thesis / Master of Engineering (MEngr) / Scope and contents: In this report, a method for calculating the longitudinal shear capacity of the slab of simply-supported steel-concrete composite beams is presented. The method is based on analysing the stresses at failure of the concrete elements located at the slab shear surface. In this analysis, the slab width and the shear span are found to be two main parameters that have been neglected in the empirical solutions previously adopted.

The strength and behavior of composite slabs are governed by the shear interaction between the concrete and the steel deck. The interaction property depends on several factors and it is not possible to express the relationship from a purely analytical basis. As such, analysis and design methods available today use the interaction property derived from full scale performance tests. In numerical modeling, the interaction property is obtained from a variety of elemental push off tests which, for the most part, do not represent actual slab bending. This research comprises experimental, analytical and numerical investigations of composite slabs. The central objective of the experimental work is to develop a new small scale test method for evaluating the performance and behavior of composite slabs and also for determining the shear interaction property for use in numerical analysis. The characteristics of the new test specimen are simple, easy and economical to conduct, as well as comparable in performance and behavior with the more common full slab test. The analytical study was conducted to determine whether data from small scale tests can be used in the present analytical methods to predict the strength of the actual slabs, to use the same test data for input in the numerical analysis, and to improve the present Partial Shear Connection (PSC) design procedure. A model that relates the shear bond stress to slab slenderness, which can be used to estimate the shear interaction property for slabs with any slenderness, was developed. Finally, a finite element study was conducted to develop a simple modeling method that is suitable for analyzing composite slabs with variable slenderness. Parametric analyses to determine the effect of slenderness on the performance and behavior of composite slabs, and on the accuracy of the present design methods were also conducted. The results of this investigation demonstrate that the small scale test is feasible as a replacement for the full scale test. Data from the small scale test can be used not only in the analytical methods but also in the numerical analysis, thus eliminating the need for separate push off type tests. / Ph. D.

This article presents the design procedures for the use of precast hollowcore slabs in steel-concrete composite construction. The paper also summarises the recent and on-going work on the transfer of this knowledge into the Australian construction industry. Whilst it is common practice to use precast concrete planks in Australian building construction, the benefits of composite behaviour with steel beams have not yet been fully realised with these systems, (National Precast Concrete Association of Australia, 2003). The use of precast hollowcore slabs in steel composite construction has seen rapid growth in popularity since it was first developed in the 1990s. The main advantages of this form of construction are that precast hollowcore slabs can span up to 15 metres without propping. The erection of 1.2 metre wide precast concrete units is simple and quick, shear studs can be pre-welded on beams before delivery to site thereby offering the savings associated with shorter construction times.

Predicting the long-term behavior of steel-concrete composite structures is a very complex systems problem, both because obtaining reliable information on material properties related to creep and shrinkage is not straightforward and because it is not easy to clearly determine the correlation between the effects of creep and shrinkage and the resultant structural response. Slip occurring at the interface between the steel and concrete may also make prediction more complicated. While the short-term deflection of composite beams may be easily predicted from fundamental theories of structural mechanics, calculating the long-term deflection is complicated by creep and shrinkage effects on the concrete deck varying over time. There are as yet no comprehensive ways for engineers to reliably deal with these issues, and the development of a set of justifiable numerical standards and equations for composite structures that goes beyond a simple commentary is well overdue. As the first step towards meeting this objective, this research is designed to identify a simple method for calculating the long-term deformations of steel-concrete composite members based on existing models to predict concrete creep and shrinkage and to estimate the time-varying deflection of steel-composite beams for design purposes. A brief reexamination of four existing models to predict creep and shrinkage was first conducted, after which an analytical approach using the age-adjusted effective modulus method (AEMM) was used to calculate the long-term deflection of a simply-supported steel-concrete composite beam. The ACI 209R-92 and CEB MC90-99 models, which adopt the concept of an ultimate coefficient, formed the basis of the models developed and examples of the application of the two models are included to provide a better understanding of the process involved. For the analytical approach using the AEMM, the entire process of calculating the long-term deflections with respect to both full and partial shear interactions is presented here, and the accuracy of the calculation validated by comparing the model predictions with experimental data. Lastly, the way the time-dependent deflection varies with various combinations of creep coefficient, shrinkage strain, the size of the beam, and the span length, was analyzed in a parametric study. The results indicate that the long-term deflection due to creep and shrinkage is generally 1.5 ~ 2.5 times its short-term deflection, and the effects of shrinkage may contribute much more to the time-dependent deformation than the effect of creep for cases where the sustained live load is quite small. In addition, the composite beam with a partial interaction exhibits a larger mid-span deflection for both the short- and long-term deflections than a beam with a full shear interaction. When it comes to the deflection limitations, it turned out that although the short-term deflections due to immediate design live load satisfy the deflection criteria well, its long-term deflections can exceed the deflection limitations. / Master of Science

A utilização do elemento estrutural viga mista aço-concreto, que consiste da associação de vigas de aço (perfil do tipo I) com lajes de concreto (maciça ou com forma de aço incorporada), têm sido considerável nas obras de engenharia civil, tanto no contexto mundial como no Brasil. Parte da eficiência desse elemento estrutural está diretamente relacionada ao trabalho em conjunto de ambos os materiais, ou seja, do tipo de interação entre aço e concreto. Para um comportamento estrutural adequado das vigas mistas, essa interação é garantida por meio de elementos metálicos denominados conectores de cisalhamento, cujas principais funções consistem em transferir forças de cisalhamento longitudinais do concreto para o aço na interface entre laje e viga, bem como impedir a separação vertical entre laje de concreto e perfil metálico, movimento conhecido como uplift. Nesse sentido, o presente trabalho tem como objetivo principal uma pesquisa com base em referências bibliográficas sobre o assunto vigas mistas, bem como é proposta a elaboração de um modelo numérico tridimensional para viga mista, objetivando simular satisfatoriamente seu comportamento estrutural, em temperatura ambiente e em situação de incêndio, cujos resultados serão comparados com valores, obtidos numérica e experimentalmente, extraídos de trabalhos apresentados por outros pesquisadores. Para a modelagem numérica, utilizou-se o código de cálculo ABAQUS 6.3-1, elaborado com base nos métodos dos elementos finitos (MEF) / Composite steel-concrete beam have been commonly considered in steel-framed building used in civil engineering, not only in Brazil but also in the worldwide context. The efficiency of this structural element is directly related with the type of interaction between steel beam and concrete slab, which is assured using metallic elements called shear connectors, with the objective to transfer longitudinal shear forces from concrete slab to steel beam, in the interface, and avoid the vertical separation between concrete slab and steel beam (uplift). In this sense, the aim of the present work is to carry out a bibliographical review about composite steel-concrete beam, as well as propose a three dimensional non-linear procedure for modeling only full shear connection in composite beam. The three-dimensional numerical models constructed must be capable of predicting de response of composite beam, in ambient temperature an also in elevated temperatures (fire conditions). The computer program ABAQUS 6.3-1, based on finite element method, was used to analyze the numerical modeling. The accuracy of the three-dimensional numerical models are demonstrated by analyses of the results obtained with the models which are compared with the experimental results, obtained and presented by others researches

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Com base em um cenário econômico favorável combinado aos avanços tecnológicos das ciências dos materiais e processos de construção, nas últimas três décadas, as cidades brasileiras têm apresentado um crescimento substancial, no que diz respeito à construção de edifícios residenciais e comerciais de múltiplos andares. Atualmente, estes edifícios apresentam níveis de esbeltez elevados e têm sido construídos com estruturas cada vez mais ousadas e que englobam a experiência e o conhecimento dos engenheiros de estruturas. Como o principal objetivo dos projetistas está associado à concepção de estruturas mais leves, o projeto estrutural requer um conhecimento teórico substancial a fim de tornar compatíveis os requisitos arquitetônicos com as condições necessárias para a estabilidade. Assim sendo, o objetivo desta dissertação de mestrado é o de investigar o comportamento estrutural estático e dinâmico (linear e não linear) de um edifício misto (aço-concreto) de 20 pavimentos. Para tal, o estudo apresenta os resultados de análises estáticas e dinâmicas lineares e não lineares para ações de serviço. O comportamento estrutural do edifício, quando submetido às ações dinâmicas induzidas pelo vento, também foi investigado. Os resultados revelam que edifícios esbeltos merecem atenção especial, no que diz respeito à concepção do projeto estrutural, sendo que seu comportamento deve ser verificado através de metodologias completas que incluam análises do tipo estática e dinâmica (lineares e não lineares). / Based on a favorable economic scenario and technological advances of material sciences and construction processes, in the last three decades, the Brazilian cities have presented a substantial growth, with respect to construction of residential and commercial multi-storey buildings. Nowadays, these buildings present greater slenderness and have been constructed with increasingly daring structures that encompass the experience and knowledge of structural designers by using newly developed materials and technologies boosted by the ever-growing investigations on this field. As the structural designer main objective is related to produce increasingly lighter structures its conception requires a substantial amount of theoretical knowledge associated to structural design and construction processes, in order to make compatible the requirements of architecture with the necessary conditions to the stability. Considering all aspects mentioned before, the objective of this master dissertation is to investigate the structural behavior of a 20 floors steel-concrete composite building, based on static and dynamic analyses (linear and nonlinear). The present study has considered the results of a linear-elastic and non-linear geometric analysis for serviceability actions. The structural behavior of a 20 floors steel-concrete composite building under dynamic actions induced by the wind was also investigated. As a result, it must be emphasized that these buildings deserve special attention from the architectural and structural design and its behavior should be verified by methods including a full static and dynamic analysis (linear and non-linear).

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Com base em um cenário econômico favorável combinado aos avanços tecnológicos das ciências dos materiais e processos de construção, nas últimas três décadas, as cidades brasileiras têm apresentado um crescimento substancial, no que diz respeito à construção de edifícios residenciais e comerciais de múltiplos andares. Atualmente, estes edifícios apresentam níveis de esbeltez elevados e têm sido construídos com estruturas cada vez mais ousadas e que englobam a experiência e o conhecimento dos engenheiros de estruturas. Como o principal objetivo dos projetistas está associado à concepção de estruturas mais leves, o projeto estrutural requer um conhecimento teórico substancial a fim de tornar compatíveis os requisitos arquitetônicos com as condições necessárias para a estabilidade. Assim sendo, o objetivo desta dissertação de mestrado é o de investigar o comportamento estrutural estático e dinâmico (linear e não linear) de um edifício misto (aço-concreto) de 20 pavimentos. Para tal, o estudo apresenta os resultados de análises estáticas e dinâmicas lineares e não lineares para ações de serviço. O comportamento estrutural do edifício, quando submetido às ações dinâmicas induzidas pelo vento, também foi investigado. Os resultados revelam que edifícios esbeltos merecem atenção especial, no que diz respeito à concepção do projeto estrutural, sendo que seu comportamento deve ser verificado através de metodologias completas que incluam análises do tipo estática e dinâmica (lineares e não lineares). / Based on a favorable economic scenario and technological advances of material sciences and construction processes, in the last three decades, the Brazilian cities have presented a substantial growth, with respect to construction of residential and commercial multi-storey buildings. Nowadays, these buildings present greater slenderness and have been constructed with increasingly daring structures that encompass the experience and knowledge of structural designers by using newly developed materials and technologies boosted by the ever-growing investigations on this field. As the structural designer main objective is related to produce increasingly lighter structures its conception requires a substantial amount of theoretical knowledge associated to structural design and construction processes, in order to make compatible the requirements of architecture with the necessary conditions to the stability. Considering all aspects mentioned before, the objective of this master dissertation is to investigate the structural behavior of a 20 floors steel-concrete composite building, based on static and dynamic analyses (linear and nonlinear). The present study has considered the results of a linear-elastic and non-linear geometric analysis for serviceability actions. The structural behavior of a 20 floors steel-concrete composite building under dynamic actions induced by the wind was also investigated. As a result, it must be emphasized that these buildings deserve special attention from the architectural and structural design and its behavior should be verified by methods including a full static and dynamic analysis (linear and non-linear).

A utilização do elemento estrutural viga mista aço-concreto, que consiste da associação de vigas de aço (perfil do tipo I) com lajes de concreto (maciça ou com forma de aço incorporada), têm sido considerável nas obras de engenharia civil, tanto no contexto mundial como no Brasil. Parte da eficiência desse elemento estrutural está diretamente relacionada ao trabalho em conjunto de ambos os materiais, ou seja, do tipo de interação entre aço e concreto. Para um comportamento estrutural adequado das vigas mistas, essa interação é garantida por meio de elementos metálicos denominados conectores de cisalhamento, cujas principais funções consistem em transferir forças de cisalhamento longitudinais do concreto para o aço na interface entre laje e viga, bem como impedir a separação vertical entre laje de concreto e perfil metálico, movimento conhecido como uplift. Nesse sentido, o presente trabalho tem como objetivo principal uma pesquisa com base em referências bibliográficas sobre o assunto vigas mistas, bem como é proposta a elaboração de um modelo numérico tridimensional para viga mista, objetivando simular satisfatoriamente seu comportamento estrutural, em temperatura ambiente e em situação de incêndio, cujos resultados serão comparados com valores, obtidos numérica e experimentalmente, extraídos de trabalhos apresentados por outros pesquisadores. Para a modelagem numérica, utilizou-se o código de cálculo ABAQUS 6.3-1, elaborado com base nos métodos dos elementos finitos (MEF) / Composite steel-concrete beam have been commonly considered in steel-framed building used in civil engineering, not only in Brazil but also in the worldwide context. The efficiency of this structural element is directly related with the type of interaction between steel beam and concrete slab, which is assured using metallic elements called shear connectors, with the objective to transfer longitudinal shear forces from concrete slab to steel beam, in the interface, and avoid the vertical separation between concrete slab and steel beam (uplift). In this sense, the aim of the present work is to carry out a bibliographical review about composite steel-concrete beam, as well as propose a three dimensional non-linear procedure for modeling only full shear connection in composite beam. The three-dimensional numerical models constructed must be capable of predicting de response of composite beam, in ambient temperature an also in elevated temperatures (fire conditions). The computer program ABAQUS 6.3-1, based on finite element method, was used to analyze the numerical modeling. The accuracy of the three-dimensional numerical models are demonstrated by analyses of the results obtained with the models which are compared with the experimental results, obtained and presented by others researches

Environmental awareness has strongly increased these last years, especially in the developed countries where societies have become increasingly preoccupied by the natural resource depletion and environmental degradation. At the same time, the increasing mass transportation demand throughout the European Union requires the development of new infrastructures. Life Cycle Assessment is increasingly used to provide environmental information for decision-makers, when a choice is to be made about the transportation mode to be implemented on a given route. In a life-cycle perspective, not only the environmental pressure of the operation of vehicles but also the burden from the infrastructure, in particular bridges as key links of the road and railway networks, has to be assessed when comparing transportation modes. Based on an extensive literature review, a simplified quantitative LCA is implemented in order to compare the environmental performance of two railway bridge designs. It is meant to be useful at an early stage in the design process, when no detailed information about the bridge is available, and when rough environmental estimations are needed. The Excel based model covers the entire life-cycle of the bridge, from raw material extraction to construction materials recycling and disposal. Various assumptions and omissions are made to narrow the scope of the analysis. For instance, processes that are found insignificant in the literature are omitted, and only a limited set of relevant emissions and impacts to the environment is considered. The model provides fully transparent results at the inventory and impact assessment level. The streamlined approach is tested by comparing the environmental burden throughout the life-cycle of a steel-concrete composite railway bridge on a single span, equipped with either a ballasted or a fixed concrete single track. The results show that the environmental impacts of the fixed track alternative are lower than that of the ballasted track alternative, for every impact categories. In a sustainable development perspective, it would thus have been preferable to install a fixed track over the bridge to reduce its overall impact on the environment by about 77%. The raw material phase is found decisive in the life-cycle of both alternatives. The frequency of the replacement of the track is identified as a key environmental parameter, since the road traffic emissions during bridge closure nearly overwhelmed the other life-cycle stages.