Sistema inteligente baseado nas redes neurais artificiais para dosagem do concreto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desempenho operacional e energético, segundo a norma OECD – code 2 de dois tratores agrícolas 4x2 TDA com motores de 132 kw em pista concreto e solo agrícola

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação do comportamento reológico na retração plástica e na fissuração de argamassas de concreto auto-adensável

This paper investigated the influence of the amount of superplasticizer and mineral adding - silica fume and basaltic filer - in plastic shrinkage and cracking of self-compacting concrete (SCC) mortars. Initially analysis was performed of the rheological behavior of cement paste and mortars phases of the compositions of SCC. Then the deformations of mortars were measured by the effect of shrinkage and evaluation of cracking. On plastic shrinkage and cracking, the composition with silica fume showed superior results, independent of wind and superplasticizer content, relative to the composition with addition of basalt filler. However, the composition with silica fume showed superior results only in the tests with imposed ventilation at vertical plastic deformation. The rheological behavior affected directly the plastic shrinkage and cracking at early ages, fact confirmed by the analysis of capillary pressures of mortars tested.

Aderência aço-concreto: simulação numéricadosensaios de arranchamento pull-out e APULOT usando o programa ATENA

The bond between steel and concrete is essential for the existence of reinforced concrete structures, as both materials act together to absorb structural strain. The bond phenomenon is considered to be complex regarding many factors that affect it. Several types of bond tests have been proposed over years. One is the modified proposed of pull-out test, which was elaborated by Lorrain and Barbosa [1] called APULOT test (Appropriete pull-out-test). Based on experimental results obtained by Vale Silva[2] either by conventional pull-out tests, or by modified pull-out test, APULOT, seeks to know the numeric behavior of bond steel-concrete through a numerical simulation using a calculation code ATENA which is based on the Finite Element Method (FEM). The numerical simulation provided better evaluate the stress distribution and cracking that occurs during the test, thereby becoming a valuable tool to support the experimental project that aims to validation, validation partially or not recommend the modified bond test steel-concrete - APULOT test - as quality control test of structural concrete. The numerical results showed good representation compared to experimental results.

Análise da durabilidade do concreto de alto desempenho com adição de cinza de casca de arroz e borracha de pneu

Since the Seventies, there has been a growing degradation of concrete structures in Brazil. For that reason, much research has been made on the durability of those structures, aiming at contributing towards quality improvement and reduction of maintenance and repair costs. This study evaluates the behavior of the durability of high-performance concrete with additions, replacing part of the cement and aggregates with rice husk ash and tire rubber, respectively. Durability tests were carried out in which concrete was subjected to several degradation processes, such as the action of water, temperature, salts and acid solution. The results indicated that the addition of active silica or rice husk ash, both with tire rubber did not worsen the durability of concrete. In fact, rubber proved to be very effective in preventing the action of chemical agents, high temperatures and the penetration of water. Rice husk ash, despite the larger diameter of particles, had similar results to that of the active silica.

Estudo de adobes melhorados com cimento e adição de resíduos de concreto

Pós-graduação em Engenharia Civil - FEIS

Tubos de concreto com adição de resíduos de borracha de pneu

Pós-graduação em Engenharia Civil - FEIS

Estudo da viabilidade do emprego do pó de mármore para produção de concreto autoadensável e substituição parcial dos agregados por pérolas de poliestireno expandido (EPS)

Pós-graduação em Engenharia Civil - FEIS

Sistema de proteção superficial de estruturas de concreto de usinas hidrelétricas para controle da reação álcali-agregado

Pós-graduação em Engenharia Civil - FEIS

Determinação de parâmetros reológicos de argamassas e concreto através de técnicas alternativas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Processamento de frutos de abacaxizeiro cv smooth cayenne: perfil de açúcares e ácidos dos sucos e composição nutricional da farinha de cascas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise do processo de execução de edificações compostas por paredes de concreto executadas in loco

This work presents a fast, easy, standardized and planned method to build family homes in order to collaborate with the decline of housing deficit and, at the same time, meet families who wish to invest in building their own houses, once that our country is experiencing an economical prosperity . This method has been widely used nowadays because it is being deployed in large-scale and in a standardized pattern, reducing decreasing significantly the construction time. The concrete wall, shaped in loco depends on unique processes. For this reason, a well trained staff is required so the constructive process can be executed in a fast pace, showing better results than other construction methods. This project will address all the materials used to build the molded concrete walls in loco, their sequence assembly, application, types, characteristics and performances. At the end, a way used by building companies of locating the concrete will also be given. Although there is no specific Brazilian norm for this type of construction, a study on this topic will soon be released. Therefore, the studies for the execution of this project were based on Brazilian standards prevailing at the time, construction magazines and books that are based on building methods considered more common

Verificação de terceira ordem de estruturas de concreto armado de edíficios

The change in design of a building can occur during its construction process, especially when this change involves greater amount of profit for the building company, as it is the case of adding extra floors. However, there must be an analysis of the structure of the building in order to see if it is possible to increase the number of floors without the need of reinforcement, as this need would result in higher costs for the building company. This graduation report presents this analysis by using the methods of third order verification of reinforced concrete structures

Estudo da eficiência de reforços estruturais em vigas de concreto armado com o uso de chapas de aço coladas com resina epóxi: uma análise qualitativa

In civil engineering, a structure is the whole sustainment of a construction and, thus, it is important that it remains intact throughout its lifetime. An engineering construction must last for decades without losing its functionality. However its purpose may be altered and several times the original structure does not meet the new needs of use. Still, in new buildings, the functionality is altered due to possible flaws in execution and the structure, invariably does not reach the desired solicitation needs. In cases like this, the commonly adopted solutions are, basically, the demolishment followed by the reconstruction of the desired mold or the structural reinforcement. This second option, for long years, has not been put to practice due to certain factors such as the high costs for its implantation, use of inadequate reinforcement execution techniques, and the culture of people involved in the area regarding its use and, in this case, the option would always be the reconstruction. Thoughtout the years, some techniques were developed to allow the execution of structural reinforcements with low costs and in efficient ways. An interesting, fast, efficient and economical technique is the structural reinforcement through metal sheets put together with epoxy resin that can be applied in beams, slabs and pillars. In the present work the different behavior of beams reinforced with this technique. Steel is a very recommended material for these reinforcements due to its characteristics related to traction, compression and the effectiveness of the technique related to its cost. For the attachment the epoxy resin is recommended, since it allows the joining of two materials, in this case, steel and concrete. The efficiency of this union is so considerably high that it rarely produces any flaws in adherence and, normally, when it happens it is due to problems in the execution process, not in the union of materials

Comparação de custo e viabilidade técnica de obras com parede de concreto em relação a obras de alvenaria estrutural

Are being released in the construction market in Brazil ventures called Super 6. These businesses sell the promise of delivery of the apartment in six months after the launch of the venture. To meet this deadline are being deployed the constructive method of concrete walls using aluminum shapes. This system basically consists of pouring slabs and walls once, i.e. building up the wall shapes and slab joints. On the walls are used cloth, with reinforcements in vain and corners of walls and on these screens are tied the electrical boxes and conduits. For each tower is used the so-called system of half way, i.e. the system so it is sufficient to mount the Middle deck. Using a concrete which can be deformed in the next day you can lift one deck every two days with ready electric and hydraulicsystem, without having to tow the wall doing only minor fixes in the imperfections after concrete. With this system won an incredible speed in the construction of the structure reducing in almost one-third the length of the work. This work aims to compare in terms of cost-benefit of masonry structural systems and this new concrete wall system called Super 6. For this comparison will be used as parameter values used for the achievement of the Enterprise Portal of Roses of constructor Tenda which is one of the first to use concrete wall system. This project basically consists of seven towers of six floors each and will be budgeted the cost of this project if it were held in structural masonry. From these data it will be possible to make a comparison about the actual beneficial to adopt this system