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Bridges without expansion joints are called "integral bridges." Eliminating joints from bridges crates concerns for the piles and the abutments of integral bridges because the abutments and the piles are subjected to temperature-induced cyclic lateral loads. As temperatures change daily and seasonally, the lengths of integral bridges increase and decrease, pushing the abutment against the approach fill and pulling it away. As a result the bridge superstructure, the abutment, the approach fill, the foundation piles and the foundation soil are all subjected to cyclic loading, and understanding their interactions is important for effective design and satisfactory performance of integral bridges. The ability of piles to accommodate lateral displacements is a significant factor in determining the maximum possible length of integral bridges. In order to build longer integral bridges, pile stresses should be kept low. This research project investigated the complex interactions that take place between the structural components of the integral bridge and the soil through experimental and analytical studies. A literature review was conducted to gain insight into the integral bridge/soil interactions, and to synthesize the information available about the cyclic loading damage to piles of integral bridges. The ability of the piles and the abutments to withstand cyclic loads was investigated by conducting large-scale cyclic load tests. Three pile types and three semi-integral abutments were tested in the laboratory. Experiments simulated 75 years of bridge life for each specimen by applying over 27,000 displacement cycles. Numerical analyses were conducted to investigate the interactions among the abutment, the approach fill, the foundation soil, and the piles. The original VDOT semi-integral abutment hinge experienced shear key failure as observed in two large-scale laboratory tests. The revised hinge detail did not exhibit any sign of damage. Both abutments tolerated 75-year worth of displacement cycles without any appreciable change in their behavior. Semi-integral abutments are recommended for longer integral bridges because they can reduce pile stresses. As the need to build longer integral bridges grows, the role of the semi-integral abutments is expected to become more important. The data from the experimental program indicates that steel H-piles are the best pile type for support of integral abutment bridges. Concrete piles are not recommended because under repeated lateral loads, tension cracks progressively worsen and significantly reduce vertical load carrying capacity of these piles. Pipe piles have high flexural stiffness, which results in an undesired condition for the shear stresses in the abutment. For this reason, stiff pipe piles are not recommended for support of integral bridges. Numerical analyses indicate that the interactions between the approach fill and the foundation soils create favorable conditions for stresses in piles supporting integral bridges. Because of these interactions, the foundation soil acts as if it were softer, resulting in reduction in pile stresses compared to a single pile in the same soil without the approach fill above it. / Ph. D.

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Lors d’un scénario hypothétique d’Accident par Perte de Réfrigérant Primaire (APRP), les gainages combustibles en alliage de zirconium subissent des sollicitations thermomécaniques sévères dans des environnements chimiques très oxydants. L’évolution des conditions de pression et de température ainsi que la présence du fluide réfrigérant peuvent entraîner dans un premier temps le ballonnement-éclatement puis l’oxydation sous vapeur et la prise d’hydrogène à haute température ainsi que des chargements mécaniques axiaux lors du renoyage final.L’objectif de la thèse est d’identifier les mécanismes et les paramètres clés qui gouvernent la rupture lors de la phase de renoyage sous traction. Des essais semi-intégraux, visant à reproduire un scénario APRP sur des tronçons de gaines de Zircaloy−4, ont été réalisés afin d’étudier le comportement de ce matériau dans de telles conditions.Un seuil fonction de la durée d’oxydation à haute température, à partir duquel la gaine rompt lors du renoyage, est mis en évidence. Deux lieux de rupture sont identifiés : la zone ballonnée où l’oxydation est maximale et la prise d’hydrogène nulle, ainsi que la zone dite « d’hydruration secondaire », sous la zone ballonnée, où la prise d’hydrogène est conséquente et l’oxydation moindre. Par ailleurs, un scénario de la rupture par rapport à la chronologie du renoyage a été établi.Cependant, le traitement macroscopique de ces essais ne permet pas de discriminer ces deux lieux de rupture, car la rupture intervient indépendamment dans le ballon et hors zone ballonnée en fonction du transitoire appliqué et de la morphologie du ballonnement-éclatement. Une approche locale a été mise en place, à partir de la caractérisation microstructurale et fractographique systématique des éprouvettes d’essai, afin d’établir un critère de rupture dépendant de l’état du matériau.La distribution complexe des éléments chimiques et des phases dans l’épaisseur de la gaine a été déterminée. Les changements de phase dans le ballon fortement oxydé, menant à une microstructure globalement fragile, ont été explicités. Une loi de seuil à rupture, en zone d’hydruration secondaire, a été identifiée à l’aide des mesures d’épaisseurs de phases et du profil de teneur en hydrogène. / During hypothetical Loss-Of-Coolant-Accident (LOCA) scenarios, zirconium alloy fuel cladding tubes are subjected to severe thermo- mechanical loading conditions in highly oxidising chemical environments. Pressure and temperature evolution together with cooling water can lead to ballooning and burst followed by steam oxidation and hydrogen uptake at high temperature, and then axial loading during the final reflooding stage.This study focuses on the identification of mechanisms and key parameters which drive cladding fracture during the reflooding stage under axial tensile load.Laboratory-scale semi-integral tests simulating LOCA transients on Zircaloy−4 test rods have been realised. A fracture/no-fracture threshold of oxidation duration at high temperature has been determined. Two fracture locations have been identified: i) the burst zone with maximal oxidation and no hydrogen uptake, and ii) the “secondary hydriding” zone below the burst zone, with substantial hydrogen absorption and lower oxidation levels. Moreover, a scenario of fracture as a function of the reflooding chronology has been identified. Nevertheless, the macroscopic treatment of these tests has not permitted to discriminate these two fracture locations because fracture independently occurs in and out of the burst zone, whatever the applied transient and the balloon and burst morphologies.From systematic microstructural and fractographic characterisation of test specimens, a local approach aiming at identifying a fracture threshold as a function of the microstructural state of the material has been applied. The complex distribution of chemical elements and phases across the cladding thickness has been determined. Phase transformations in the highly-oxidised balloon, leading to a globally brittle microstructure have been explicated. In the secondary hydriding zone, a fracture threshold criterion has been identified by means of layer thickness measurements and hydrogen uptake profile.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-24T11:28:12Z No. of bitstreams: 1 2016 - Marcos Fabio de Lima.pdf: 2778933 bytes, checksum: 3359fd462f05a8841046bf8ef8191dac (MD5) / Made available in DSpace on 2017-03-24T11:28:12Z (GMT). No. of bitstreams: 1 2016 - Marcos Fabio de Lima.pdf: 2778933 bytes, checksum: 3359fd462f05a8841046bf8ef8191dac (MD5) Previous issue date: 2016-06-17 / Three experiments were conducted in animal nutrition sectors and Pastures of the Animal Science Institute of the Federal Rural University of Rio de Janeiro; Poultry Research Centre of the Instituto Federal de Educa??o Ciencia e Tecnologia do Rio de Janeiro and Feed Production Unit Bananal - SP Company Reginaves Industria e Comercio de aves. In the first experiment, there was a metabolism assay for the determination of metabolizable energy and energy corrected apparent Metabolizable (EMAn), the traditional method of excreta collection using broilers fed with extruded semi-whole soybean (SSIE) at different temperatures. The treatments consisted of four levels of extrusion temperatures of the SSIE: 60% reference diet + 40% SSIE to 90 ? C; 60% reference diet + 40% SSIE to 100 ? C; 60% reference diet + 40% SSIE to 110 ? C and 60% + 40% reference diet SSIE to 120?C. In the second experiment it was determined the true total and digestible amino acids in 300 chickens from 16 to 21 days old. The treatments were: diet SSIE to 90 ? C; diet SSIE 100 ? C; SSIE diet at 110 and at 120 SSIE diet. The third experiment was conducted to verify the diets SSIE the 110C with four different nutritional matrixes: diet with commercial soybean meal (DFS); diet with nutritional matrix SSIE the 110C and corrected (DSC); diet with nutritional matrix SSIE to 110C determined by the analysis of online NIRS (DSN) and diet SSIE nutritional matrix as Brazilian Tables (DSTB). the growth performance, economic indices and carcass characteristics of broiler chickens submitted to the treatments were analyzed. The values of AME, AME, true digestible amino acid digestibility coefficients were significantly influenced by the extrusion temperature of the semi-integral soybean. The higher EMA (3720.09 kcal / kg) and AMEn (3424.99 kcal / kg) were obtained with the extrusion temperature of the semi-integral soybean approximately 105.6 ? C. The digestible amino acid values and true digestibility coefficients were influenced by the extrusion temperature of the semi-integral soybean. The best extrusion temperatures of the semi-integral soybean estimated for the real amino acid digestibility figures were 112.12?C to lysine, methionine 107.14?C, 106.11?C to cystine, arginine 111.77 112.25 and serine. The standardization of the SSIE extrusion temperature and the proper use of nutritional matrix of this ingredient in feed formulation positively influence the performance and economic index / Foram realizados tr?s experimentos nos setores de Nutri??o Animal e Pastagens do Instituto de Zootecnia da Universidade Federal Rural do Rio de Janeiro; Centro de Pesquisas Av?colas do Instituto Federal de Educa??o Ci?ncia e Tecnologia do Rio de Janeiro e Unidade de Produ??o de Ra??es de Bananal ? SP da Empresa Reginaves Industria e Comercio de Aves Ltda. No primeiro experimento, foi realizado um ensaio de metabolismo para a determina??o dos valores de energia metaboliz?vel e Energia Metaboliz?vel aparente corrigida (EMAn), pelo m?todo tradicional de coleta total de excretas utilizando frangos de corte alimentados com ra??es contendo soja semi-integral extrusada (SSIE) em diferentes temperaturas. Os tratamentos consistiram em quatro n?veis de temperaturas da SSIE : 60% dieta referencia + 40% SSIE a 90?C; 60% dieta referencia + 40% SSIE a 100?C; 60% dieta referencia + 40% SSIE a 110?C e 60% dieta referencia + 40% SSIE a 120?C. No segundo experimento foram determinados os amino?cidos totais e digest?veis verdadeiros em 300 frangos de 16 a 21 dias de idade. Os tratamentos estudados foram: dieta com SSIE a 90?C; dieta com SSIE a 100?C; dieta com SSIE a 110?C e dieta com SSIE a 120?C. O experimento tr?s foi realizado para verificar as dietas contendo SSIE a 110?C com quatro matrizes nutricionais diferentes: dieta com farelo de soja comercial (DFS); dieta com matriz nutricional da SSIE a 110?C e corrigida (DSC); dieta com matriz nutricional da SSIE a 110?C determina pela analise do NIRS online (DSN) e dieta com matriz nutricional da SSIE conforme Tabelas Brasileiras (DSTB). Foram analisados o desempenho zoot?cnico, ?ndices econ?micos e as caracter?sticas da carca?a dos frangos de corte submetidos aos tratamentos. Os valores de EMA, EMAn, amino?cidos digest?veis verdadeiros coeficientes de digestibilidade foram influenciados significativamente pelas temperaturas de extrus?o da soja semi-integral. Os maiores valores de EMA (3720,09 Kcal/ Kg) e de EMAn (3424,99 Kcal/Kg) foram obtidos com a temperatura de extrus?o da soja semi-integral de aproximadamente 105,6?C. Os valores de amino?cidos digest?veis e coeficientes de digestibilidade verdadeiros foram influenciados pelas temperaturas de extrus?o da soja semi-integral. As melhores temperaturas de extrus?o da soja semi-integral estimadas para os valores de digestibilidade de amino?cido verdadeiro foram de 112,12?C para lisina, 107,14?C para metionina, 106,11?C para cistina, 111,77 para arginina e 112,25 para serina. A padroniza??o da temperatura de extrus?o da SSIE e a utiliza??o correta da matriz nutricional deste ingrediente na formula??o de ra??es influenciam positivamente os ?ndices produtivos e econ?micos

For creep and shrinkage investigations, relatively small cylindrical specimens are generally exposed to constant climatic conditions. The derived mainly empirical prediction models are used for the calculation of large engineering structures with massive cross-sections. In this paper, the expected values of the material models according to fib Model Code 2010 and Eurocode 2 are compared with monitoring data, which were acquired over a period of more than 12 years during a structural health monitoring of a large viaduct. It was found that in addition to the measured continuous increase in the viscous deformations, seasonal fluctuations due to climatic influences could also be detected. The numerical calculations show that the material models differ significantly in their magnitude and time course of the predicted viscous concrete deformations. In comparison with the monitoring data, a good agreement was achieved when using the material models according to Eurocode 2. The models of the fib Model Code 2010, on the other hand, underestimated the deformations of the massive bridge girder.