222 resultados para Concreto de alto desempenho : Materiais : Construção civil


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The objective of this work was collect information of articles published previously and carry out a study about them, including contents and interesting stuff that bring growth regarding the construction residues utilization and demolition (RCD), that today provides many environmental impacts. The need of utilization of the RCD in Brazil and in the world earned bigger attention world speaking, therefore the industry of the civil construction is had as one of the biggest present residues output springs. For it present a point that can be applied the RCD, is discussed in that work the kinds and structures of floors, where are presented the layers and, finally, a short argument about the possible and economic feasabilities job of the residues recycled in some layers of the structure of floor

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Since the early twenty-first century, the construction sector has been the second largest on the rise in the Brazilian industrial sector, with a growth of 1.4% in 2012, and is likely to remain at this level for a long time. However, unlike decades ago, the industry has been seeking in its manufacturing process, sustainable materials, encompassing in their works the concept of sustainability. Thus, the timber sector seeks to satisfy a market increasingly demanding, innovating techniques and utilization being less aggressive to the environment. The purpose of this study was to produce and evaluate the mechanical strength of the composite cement with the addition of wood residues and slag low oven. Therefore, it was made 42 specimen cement-slag-wood, carried out in two steps. Since at the first, it was varied only the slag particle size, and at the second, through the best result of the previous step, it was varied the wood particles granulometry. The mechanical performance of the composite was evaluated by the results obtained in the compression test and the physical test for determining the density of the material. In the first step of the process can be concluded that the best result was achieved with the use of slag particles retained on the 60 mesh sieve. In the second phase of the study concluded that the best results were achieved with wood particles with the large particles, i.e. particles retained on the 10 mesh sieve. Both in the first and in the second step it can be seen that there has been the influence of the particle size of the waste materials. With the obtained results, could be evaluated that the use of waste for the production of cement-slag-wood composite showed lower performance when compared to the results obtained in studies without the use of waste. However, some applications are feasible to be performed with the use of composite wood-cement-slag

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This work presents the results obtained in analyzes of aggregates from construction and demolition waste produced by the plant of the City of Guaratinguetá. Using this data and comparing with the specifications of NBR 15115, it was found that the materials do not possess the requisite minimum characteristics to be utilized as a basis for low-pavement traffic. In order to identify the main reasons of the material does not fit in the standard, we used the data obtained in a study conducted by Professor. Dr. Luiz Eduardo de Oliveira at the plant of the company AB Environmental Solutions Ltd., located in Pindamonhangaba. With different characteristics, the aggregates from construction and demolition waste produced by this plant showed the possibility of using pavements. The use of these residues in paving reduces the impact on the environment caused by construction.

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Taking as starting the environmental, social and economic impact of construction and demolition waste in Brazilian cities were created legal mechanisms for management and administration, seeking to minimize the impacts to the maximum, since the irregular deposition can be characterized as environmental crime. CONAMA Resolution No. 307 of 2002 establishing the mandatory implementation of an Integrated Management System Construction Waste and Demolition, guiding the classification and designation of the waste generating agents, collection agents and transporters, and the areas of culling and disposal of waste. The technical partnership between the Ministry of Cities, the Environment Ministry and the Caixa Econômica Federal, coordinated by Pinto & Gonzales (2005) Management in the work and management of construction waste, proposed a guidance manual to guide the implementation of a System Integrated Management of Construction Waste in Municipalities. The municipality of Guanambi in the state of Bahia, in full economic rise, lacks a waste management of construction and demolition, since there has areas for the disposal of waste being proposed in this paper the diagnosis of waste generation in the municipality as part of the methodology proposed by the work of Pinto & Gonzales (2005).

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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

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A teoria em finanças tem evoluído cada vez mais aproximando a teoria financeira às práticas reais adotadas nas empresas e nos mercados financeiros. A partir de Modigliani e Miller, que contribuíram para o ramo das finanças com a teoria da Irrelevância Financeira, o caminho se abriu para uma série de debates a cerca da importância das variáveis financeiras na determinação do valor da empresa. Foram levantados questionamentos a respeito da perfeição dos mercados e apresentado argumentos como a assimetria de informações, os custos de agência, a restrição financeira e outras implicações à teoria do investimento. Atualmente o que se sabe é que o fator investimento está altamente ligado às finanças e, portanto, relaciona-se com os meios de financiamento presentes no mercado e com a organização interna e financeira das firmas, esse ramo de estudo recebe o nome de Finanças Corporativas. Diante da teoria financeira, o objetivo é analisar a indústria siderúrgica de duas economias atualmente em destaque, Brasil e China através da análise econômico-financeira de quatro empresas de capital aberto do setor: Gerdau, Usiminas, Baosteel e Masteel. Cabe destacar que a indústria siderúrgica é base para outras indústrias, como construção civil, automóveis, máquinas, entre outros e, por isso, é tida como sinalizadora do desenvolvimento econômico de um país, assim também, o Brasil e a China são caracterizados como grandes potenciais emergentes e fontes de atração de investimentos internacionais

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The aim of the present study was to investigate the corrosion resistance in chloride medium of two cylindrical steel samples from civil construction (CA-50 and CA-60). For this purpose, electrochemical measurements were performed in NaCl solution, 4.0 g/L, naturally aerated. According to electrochemical responses, it was observed an active dissolution process at open circuit potential for both steels. In this comparative study, the differences between CA-50 and CA60 were not significant, since the values of polarization resistance estimated by EIS were the same order of magnitude for both types of steel (oscillating between 200 and 500 Ohm). For all evaluated thicknesses of concrete reinforcement, these values ranged between 2 and 9 kOhm, and the lower value was associated with lower thickness, particularly at 7, 21 and 35 days. When these results were compared with those determined for the CA-60, it was found that the layer of concrete reinforcement provide a protection against corrosion in chloride medium at least ten times larger

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Pós-graduação em Engenharia Civil - FEIS

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Pós-graduação em Engenharia Civil - FEIS

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Due to the huge impact negative on the environmental caused by the civil construction, the university plays a majorital role in the proposal of studies and projects that aim the sustainable building. Nowadays, it has been noted the great demand for projects which contain a systemic focus in the tripod of the sustainable development, that is to say, more and more the consumers are demanding that the final result of a project contemplate the social, economic and environmental areas. According to the National Industry Confederation (CNI) and the Brazilian Chamber of the Industry and the Construction (CBIS), the goal for 2020 is that the constructions have an environmental performance 20% higher in comparison to the actual one, starting with an index defined by many indicators, such as: water consumption, energy, residues generation and social-environmental performance of the bought products. In this case, the theme of the project comes around the adequation of scholar institutions to the sustainable construction through simple changes of tecnologies and habits aiming the growth of the environmental eficiency of the enterprise and, consequently, the improve of sustainable practices inside the institution. Once the change is proposed, it will be furnished datas liable of reproduction for the adequation of others scholar institutions, according to it's necessity or interest. After the realization of the studies, it was possible to notice that the environmental performance of a scholar institution can be improved through the implantation of tecnologies of fast return in the investment, such as: flow reducers, rain water reuse system, green roof, retrofit of lamps and execution of a photovoltaic system. Besides the fast return of investment, the monthly economy of the applied tecnologies combined can reach 75% when compared to the actual spending with water and electric energy

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Two of the major problems caused by construction activity are the production of construction and demolition waste (CDW) and the exploitation of mineral resources, causing big impacts on the environment. Therefore, the recycling has been shown as an alternative to mitigate the harmful effects of waste on the urban environment and prevent the exploitation of new raw materials. This course work aims to study the behavior of recycled aggregates from Vale do Paraíba in concrete and mortar. Initially, it presents the definitions of recycled aggregates according to CONAMA Resolution No. 307/2002, the aggregate settings for concrete and mortar (such as the grain size, its origin and density, and the characterization parameters according to ABNT), and the definition of ACI method of concrete mix design. Afterwards, it presents the characterization of materials separated by assays. After that, it shows the theoretical concrete proportioning applying the ACI method and experimental concrete proportioning. Then, the analysis of results is performed to finally conclude that the materials provided can't be used to replace natural aggregates because they cannot have the same performance. With the studies, it could be observed that the recycled aggregate presents a great complexity and diversity in origin, therefore the form how the material should be handled requires great care

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This work talks about the importance of the steel adhesion to concrete, reinforced concrete structures, their testing and forms of measurement used and how the results are used in the structural design, which uses as a reference the NBR 6118 and NBR 7480. It also deals with the importance of a reliable assessment, discussing failures that the test used, NBR 7477, features in specific circumstances, as discussed under the EC-094. It also presents an initial proposal for simplified pullout test, which aims to analyze the grip on steel bars with diameter less than 10 mm, which results when used standardized testing by ABNT NBT 7477, has shown excessive variability, the main criticism of the trial today used without distinction to be established thick or thin bars. The proposal also presented methodology is in the consolidation phase, given the time and the volume of necessary tests. For this reason it is not possible to make a comparison between the values obtained and the results of the test used on the basis of the standard in force, this can only be done once the front with a continuation of this work

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As áreas de empréstimo em hidrelétricas são as áreas remanescentes da construção da fundação da barragem e podem ser consideradas áreas degradadas, pois delas foram retirados os horizontes superficiais do solo. Este trabalho teve como objetivo estudar a recuperação de um Latossolo Vermelho distrófico, degradado por construção civil (Usina Hidrelétrica de Ilha Solteira-SP), por meio de adubação verde e aplicação de calagem e gessagem. Os tratamentos constituíram-se de: testemunha (solo mobilizado e vegetação espontânea); mucuna-preta e guandu até 1994. Depois foram substituídos por feijão-de-porco; calcário + mucuna-preta; calcário + guandu até 1994. Nova substituição foi feita por feijão-de-porco; calcário + gesso + mucuna-preta e calcário + gesso + guandu até 1994. Outra substituição foi feita por feijão-de-porco. Esses tratamentos foram estabelecidos em blocos casualizados com quatro repetições: após quatro anos com os adubos verdes, um ano com milho, um ano com aveia-preta e dois anos com braquiária. Foram avaliados: pH, teores de Ca2+, Mg2+, P, K, capacidade de troca catiônica, saturação por bases e teor de matéria orgânica. Os tratamentos adotados estão recuperando os atributos químicos do solo degradado, e a mucuna-preta apresentou os melhores resultados, quando comparada ao guandu e feijão-de-porco. Os efeitos da recuperação dos atributos químicos do solo alcançaram a profundidade de 0,0-0,2 m. As técnicas adotadas para recuperação desses atributos químicos (adubação verde, calagem e gessagem) no primeiro ano atingiram a profundidade do solo de 0,0-0,1 m e, somente após cinco anos, de 0,0-0,2 m.

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Hymenolobium petraeum Ducke é uma espécie arbórea pertencente à família Leguminosae conhecida popularmente por angelim-pedra. Apresenta alto valor comercial, com madeira muito utilizada na construção civil e marcenaria. Este trabalho teve por objetivo descrever morfologicamente o fruto, a semente e as plântulas, assim como, determinar as temperaturas cardeais para a germinação de sementes de angelim-pedra. Foram determinados o comprimento, a largura e a massa fresca de frutos e sementes. Para os testes de germinação foram utilizadas três repetições de 50 sementes, colocadas em placas de Petri e mantidas em germinadores nas temperaturas de 15, 20, 25, 30, 35 e 40°C e fotoperíodo de 12 horas. Os frutos são legumes-samaróides, indeiscentes, oblongos e unicarpelares. As sementes são de coloração castanho-escura, oblongas, estenospérmicas, exalbuminosas e com plúmula inconspícua. A raiz primária é branca e pubescente na região próxima ao colo; a parte aérea das plântulas possui pilosidade branca, protófilos compostos imparipinados e com inserção oposta, epicótilo verde, ereto, cilíndrico e piloso e os metáfilos imparipinados e com inserção alterna-espiralada. A germinação é semi-hipógea criptocotiledonar. Para de sementes de angelim-pedra as temperaturas máximas de germinação estão acima de 35°C e a mínima abaixo de 15°C, enquanto a faixa de temperatura ótima para germinação está entre 25 e 35°C.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)