Orientador: Vinicius Fernando Arcaro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil / Made available in DSpace on 2018-08-09T14:58:15Z (GMT). No. of bitstreams: 1 Pinto_AntonioCarlosAlvarenga_M.pdf: 2870920 bytes, checksum: cffdfb27613fef6b77831bd28b0b89f3 (MD5) Previous issue date: 2006 / Resumo: Descreve-se, em forma cronológica, as etapas de planejamento, projeto e construção de um empreendimento habitacional com 351 unidades, localizado na cidade de Campinas, SP. São apresentados, também, comentários, críticas e sugestões para aperfeiçoamento dos processos construtivos adotados. Apresenta-se, ainda, a análise estrutural e dimensionamento (verificação) dos elementos estruturais de concreto armado de uma residência em dois pavimentos construída com a tecnologia objeto de estudo desse trabalho / Abstract: In a chronological order, the planning, the project and the construction steps of a residential enterprise, containing 351 units, in the city of Campinas, São Paulo, Brazil, are described. Comments, critical analyzes and suggestions are presented for the improvement of the construction process as well. Also, the paper details the structural analysis and dimensions of the structural elements of a two floor reinforced concrete residential building built under the technology proposed here / Mestrado / Estruturas / Mestre em Engenharia Civil

M. Phil. / The purpose of this research is to see if on-site portable pull-out tests in South Africa on post-installed chemical and mechanical fixings can produce similar results to internationally laboratory tested fixings. The method used in the field study was to use typical South African 25 MPa, 75 mm slump ready mix concrete as supplied by a reputable supplier and to test several types of fixings in common situations, some covered in the European Technical Approval Guidelines (ETAG) and some not. The results were analyzed against published international values and theoretical calculations for the fixings. The findings showed that the results produced using the portable equipment can show values similar to the published and theoretical values. It was also shown that this methodology can be used as a diagnostic tool to reveal installation errors. The pull-out test operator needs to be skilled to ensure a satisfactory outcome of the tests. The implications of the findings have direct bearing on: The on-site pullout testing of post installed anchors in South Africa; The diagnosing of bad anchor installation. And secondarily bearing on: The education of post-installed fixing installers and designers; The lack of standards for post-installed anchors in South Africa; The transportability of data from international research to South African conditions.

External prestressed carbon fibre reinforced polymer (CFRP) straps can be used to strengthen shear deficient reinforced concrete (RC) structures. The strengthening system is associated with a number of parameters including the number of straps, strap locations, strap stiffness, and strap prestress. The initial goal of this research was to identify the optimum values for these parameters in order to design an efficient and effective shear retrofitting system. The shear friction theory (SFT) and modified compression field theory (MCFT) were identified as potential predictive theories to model the shear behaviour of RC beams retrofitted with CFRP straps. Possible modifications to the theories to reflect CFRP prestressed straps were investigated. Two popular optimisation algorithms namely the genetic algorithm (GA) and particle swarm optimisation (PSO) were coded and tested with six test functions. These algorithms were used to find the optimum shear retrofitting configurations and also to reduce the computational cost associated with the SFT and MCFT evaluations. An experimental investigation was carried out to validate the SFT and MCFT predictions for various CFRP strap configurations. The investigation consisted of an unstrengthened control beam and five CFRP strengthened beams. The shear behaviour of the beams was significantly influenced by the CFRP strap configurations. A critical load level where the beam stiffness started to deteriorate significantly was identified. It was found that there was a correlation between this load level and the yielding of the internal shear links and a rapid increase in crack openmg. The SFT and MCFT were validated using the experimental results. The peak shear capacities predicted using the SFT were more consistent with the stiffness deteriorating loads identified in the experimental investigation than with the ultimate loads of the beams. The reinforcement forces and crack opening values found from the SFT were consistent with the experimental results. The MCFT predicted the total shear response, ultimate shear capacity, crack opening, and internal and external reinforcement forces in the beams. The accuracy of the MCFT predictions reduced slightly when either the strap configuration was highly nonuniforrn or the initial prestress level in the straps was relatively low. The shear link yielding load levels predicted by the MCFT were found to be similar to the SFT predictions. By using the coded optimisation algorithms in combination with the SFT or MCFT, the optimum CFRP strap configurations were found for a selected case study. Both theories predicted an offset for the optimum strap locations from the locations associated with equal spacings along the shear span. A reasonable agreement between the SFT and MCFT predictions for the optimum shear strengths and strap locations was observed. A parametric study demonstrated that the concrete strength, internal shear link locations, beam depth, and shear span to depth ratio of the beam do not significantly influence the optimum strengthening configurations for the CFRP strap system. External prestressed carbon fibre reinforced polymer (CFRP) straps can be used to strengthen shear deficient reinforced concrete (RC) structures. The strengthening system is associated with a number of parameters including the number of straps, strap locations, strap stiffness, and strap prestress. The initial goal of this research was to identify the optimum values for these parameters in order to design an efficient and effective shear retrofitting system. The shear friction theory (SFT) and modified compression field theory (MCFT) were identified as potential predictive theories to model the shear behaviour ofRC beams retrofitted with CFRP straps. Possible modifications to the theories to reflect CFRP prestressed straps were investigated. Two popular optimisation algorithms namely the genetic algorithm (GA) and particle swarm optimisation (PSO) were coded and tested with six test functions. These algorithms were used to find the optimum shear retrofitting configurations and also to reduce the computational cost associated with the SFT and MCFT evaluations. An experimental investigation was ca1Tied out to validate the SFT and MCFT predictions for various CFRP strap configurations. The investigation consisted of an unstrengthened control beam and five CFRP strengthened beams. The shear behaviour of the beams was significantly influenced by the CFRP strap configurations. A critical load level where the beam stiffness started to deteriorate significantly was identified. It was found that there was a correlation between this load level and the yielding of the internal shear links and a rapid increase in crack opening. The SFT and MCFT were validated using the experimental results. The peak shear capacities predicted using the SFT were more consistent with the stiffness deteriorating loads identified in the experimental investigation than with the ultimate loads of the beams. The reinforcement forces and crack opening values found from the SFT were consistent with the experimental results. The MCFT predicted the total shear response, ultimate shear capacity, crack opening, and internal and external reinforcement forces in the beams. The accuracy of the MCFT predictions reduced slightly when either the strap configuration was highly nonuniform or the initial prestress level in the straps was relatively low. The shear link yielding load levels predicted by the MCFT were found to be similar to the SFT predictions. By using the coded optimisation algorithms in combination with the SFT or MCFT, the optimum CFRP strap configurations were found for a selected case study. Both theories predicted an offset for the optimum strap locations from the locations associated with equal spacings along the shear span. A reasonable agreement between the SFT and MCFT predictions for the optimum shear strengths and strap locations was observed. A parametric study demonstrated that the concrete strength, internal shear link locations, beam depth, and shear span to depth ratio of the beam do not significantly influence the optimum strengthening configurations for the CFRP strap system.

The principle of sustainability in the built environment has become much more significant in the past decade, resulting in a push to develop building systems that are more energy efficient, durable, and use fewer natural resources. For residential and light commercial buildings, insulated concrete forms (ICF) have enjoyed increasing popularity for their ability to meet these new demands. ICFs are a stay-in-place concrete formwork system for building structural walls that are also highly insulated, among other benefits. Screen-grid ICFs (SGICF) are a small subset of ICFs that tend to use less concrete than standard ICFs and are sometimes made of recycled materials. These traits make SGICFs attractive, but there is a lack of understanding of their structural characteristics due to their irregular internal concrete structure. Because of this, structures using SGICFs are limited to heights no higher than two stories. Further study should show whether SGICFs structures can safely built to greater heights. This investigation studied two types of SGICFs at a component level in order to gain understanding of their lateral force and drift ratio capacities under cyclic loading. Several variables, including steel reinforcement details, the type of concrete, and the presence of the forms, were altered to measure their impact on the performance of the systems. Test results suggested that the ICF formwork increased lateral strength by up to 100% and lateral deformation capacity by up 60% when compared to identical specimens tested with the formwork removed. Results also showed that confinement of the cement, either by mesh hoops, spiral wire, or fiber-reinforced concrete improved the drift ratio at failure up to 500% when compared to specimens with no confinement material. Computer models were created to gauge their ability to replicate the behavior of the experimental test results. The models typically overestimated the lateral load resistance of the samples by 50-100%, and even more in some cases, depending on the reinforcement. The models were not reliable in determining the drift ratio at which the sample was considered to have failed. In some cases the model failed at 50% lower lateral deformations than the test specimen, while in others the model did not fail at all. Future studies should explore refinements of the models to increase their accuracy and usefulness, as well as accounting for the contributions do to the form material. Future studies should also include using spiral wires, mesh hoops, or fiber reinforced concrete in full-scale walls to verify their efficacy in improving overall wall performance.

In this investigation, the primary objective was to study the nonlinear behavior of unbraced two-bay concrete frames and to determine the extent to which ultimate load theory or limit design can be applied to these structures. The frame behavior was investigated analytically by two methods. In the first method the frame stability equation was derived assuming that members of the frame possess an elasto-plastic moment-curvature relationship. This stability analysis was also carried out by another model consisting of a column attached to a linear spring and carrying the total frame load. The second method was through a computer program which took material and geometric nonlinearities of concrete frames into account. A model concrete frame, with a scale factor of approximately one-third was considered. Variable parameters were loading condition, column reinforcement ratio, and beam to column load ratio. For each frame, the gravity loads were increased proportionally until 75% of the frame ultimate capacity under gravity loads was reached. Then; while these gravity loads were held constant, lateral load was applied and increased to failure. The overall geometry, 21-in high columns and 84-in long beam, were kept the same for all of model frames investigated. The computer study and the stability model analysis indicated that all frames remained stable until four plastic hinges (two in each bay) formed, thus producing a combined sway mechanism. Based on the scope of this study, it appears that limit design may be employed for unbraced reinforced concrete structures.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 77-79. / by Ying-Yee Lam. / M.S.

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Ansatz meines Entwurfes war die Eigenschaft des Carbonbetons, mit ihm sehr dünne, stabile und korrosionsbeständige Konstruktionen herstellen zu können. Da ich unter anderem an der Leistungsgrenze von Betonkonstruktionen im bildhauerischen Bereich arbeite und Federn und Flügel eine sehr dünne, leistungsfähige und natürliche Einheit bilden, habe ich dies als mein Thema gewählt