Programa de Pós-graduação em Geotecnia, Estruturas e Construção Civil
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Navegando Programa de Pós-graduação em Geotecnia, Estruturas e Construção Civil por Por Orientador "ARAÚJO, Daniel de Lima"
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Item Estudo da aderência entre concreto e armadura: análise da influência das fibras de aço(Universidade Federal de Goiás, 2010-08-26) DANIN, Alice Ribeiro; ARAÚJO, Daniel de Lima; http://lattes.cnpq.br/8801080897723883Bond between steel bars and concrete allows the use of reinforced concrete as a construction material. If the bond is appropriate, the cracks will be as little as possible, so the reinforcing bar will be protected by the surrounded concrete. Therefore, the aim of this research was to analyse the influence of steel fiber on mechanical properties of concrete and on bond strength. To this end, forty eight pull-out tests had been performed. A single test‟ bar was cast into the centre of a specimen, which measured 300 mm × 200 mm × 150 mm. It had been used four bars diameters: 10 mm, 12,5 mm, 16 mm and 20 mm. The test bars were pulled out of the concrete block using a 300 kN capacity universal testing machine (UTM) operated in displacement control. The tests were performed varying the length of mounting bar tested (for five and ten times the diameter) and the presence of steel fibers. The fiber content, as in volume, ranged from 0%, 1% and 2%. It was used coarse aggregate with maximum size of 12,5 mm and concrete with target compressive strength of 60 MPa at 28 days. It was previously characterized by tests of compressive strength, modulus of elasticity, tensile strength and diametrical compression strength with displacement control. For the concrete without fibers, it was determinate the fracture energy, and for the ones with steel fiber reinforcement the toughness was determinate. There were used short steel hooked fibers, which were 35 mm long. The tests determined the bond stress in the bar in each of the specimens, which concludes that the addition of fiber in the proposed amount had just a little influence on the results of the pull-out tests for the 10 mm diameter specimens.Item Viga composta com viga e laje pré-moldadas ligadas mediante nichos :análise via modelagem computacional(Universidade Federal de Goiás, 2009-10-22) MELO, Matilde Batista; ARAÚJO, Daniel de Lima; http://lattes.cnpq.br/8801080897723883In structural system of composite beams with slab and beam, both precast, it is necessary that shear stress is transferred from the slab to the beam through the interface to assure the composite action between beam and slab. This study has the objective of assessing the behavior of composite beams with slab and beam precast connected by pockets. For this, it was developed a computational model based on the Finite Element Method using the commercial software DIANA® 9.3, which make possible the analysis of interaction between shear stresses transferred by interface to precast beam and shear stress on the precast beam due to vertical loading. In the analysis, the behavior of these beams was compared with the behavior of beams with continuous connection, usually employed. In addition, the type of beam-slab interface (with or without shear-key) was analyzed. It is tried from this analysis to confirm some models presented in the literature for design composite beams connected by pockets. Usually, the models used to design of reinforced concrete beams to shear are slightly modified to design the composite beams connected by pockets. The results show that, in fact, there is an increase on the shear stress of precast beam due to a discrete connection provided by pocketsItem Um modelo de gestão de resíduos sólidos: aplicação em indústria de artefatos e pré-moldados de concreto(Universidade Federal de Goiás, 2009-09-04) MELO, Tatiane Medeiros; TUBINO, Rejane Maria Candiota; http://lattes.cnpq.br/5775852172717383; ARAÚJO, Daniel de Lima; http://lattes.cnpq.br/8801080897723883The productive chain of the construction industry is responsible for many positive and negative impacts on the built environment. One of the negative impacts refers to the high amount of waste produced, which can be reduced through the industrialization of construction, that is, through the reduction of services at construction sites and transferring them to the factories. In this sense, the use of prefabricated structures may reduce the production of waste arising from the implementation phase of structures, such as molds and buttresses. However, if the production of the prefabricated elements in plants is not properly planned, the problems of waste production can be transferred from construction site for the industry environment. This fact was observed in some industries of artifacts and pre-molded concrete. The aim of this paper is to propose a methodology for solid waste management through the integration of the methodologies of environmental management system, cleaner production and suggestion already published of project management of construction waste envisaged by Resolution nº 307 Conama and applies this methodology in an industry artifacts and pre-cast concrete. For this, two processes of an industry of Goiânia were selected, which served as a pilot in the implementation of model solid waste management proposed. By implementing this model, it was possible to quantify the waste produced in the processes studied, as well as make significant improvements in its characterization, segregation, packaging, transportation and disposal through the implementation of opportunities for cleaner production highlighted. Moreover, mechanisms were created for the own employees were responsible for maintaining the proposed activities. As result of this study, a database about the chain of waste in the processes studied was produced, which can be used in future for the proposition of other opportunities for cleaner production in industry studied. Still, the methodology of waste management proposal can serve as a model for replication in other industries of artifacts and pre-cast concrete