60 resultados para Materiais de construção


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The production of the red pottery brick, made traditionally with clay, is a technique that is already stabled. However, in spite of the little complexity that involves the conventional process of these bricks production, it are exposed to many problems that begin in the fase of exploration of the mines, the problems get worse because of the lack of the clay's characterization, and they continue through the steps of the dough preparation, conformation of the products, the drying and the burning process. The wastefulness is shown and so is the low quality of the material produced. Among other factors, the high use of energy in the burning makes the cost of this material inaccessible to the low income consumer. Besides this, the destruction of the environment around the mines and the use of native vegetation to produce wood - the most used fuel in the pottery industry - make serious environmental damage. The production technique of a new type of simple brick (adobe), that has low cost and no environmental damage, can be the viable altemative to lower the cost of this part of the civil construction, and, consequently, in the building of cheaper houses. In this paper, the results of the mechanical resistance of the adobe brick are shown, using in its composition, clay, natural vegetable fibers, cement and plaster in a process that is completely handcrafted and manual. It is intented to make clear that are possible alternatives to be put in practice, with the simple process, using "raw earth" that has been used in the construction of houses in thousands of years, trying to solve these severe problems. Analysis and tests were performed to find results that could prove the possibility of the utilization of this kind of material. Other studies are in progress, and the new researches are necessary to enrich this work, but it stays the certainty that there is potential to produce bricks from adobe, as an alternative that has low cost to civil construction

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A housing unit was built to study the thermal performance, and of material using a composite made of gypsum and EPS ground. We used two techniques of construction, using blocks, and filling on the spot. Two compositions of the composite were studied. The blocks were fixed using conventional mortar. In the technical of filling on the spot were used PET bottles up inside the walls to provide mechanical and thermal resistance. Compression tests were realized according to the ABNT standard of sealing bricks. It is going to be shown an analysis of the thermal comfort through the use of thermocouples placed on the walls of the building, internally and externally. The manufacturing viability of houses, using recyclable materials, through the use of composite materials proposed will be demonstrated. The constructive aspects showing the advantages and disadvantages of the technique used also will be broached. The block used presents structural functions and thermal insulating, is low cost and represents an alternative to the use of EPS and PET bottles which are materials that end up occupying much space in the landfills, giving than an ecologically correct use. The results of thermal analysis shows the thermal comfort provided by the composite by the obtainment of a difference between the internal and external surfaces of the walls more exposed to the sun around 7º C. The average temperature of the air inside the building, around 28.0 º C was below the zone of thermal comfort recommended for countries with hot weather

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The static and cyclic assays are common to test materials in structures.. For cycling assays to assess the fatigue behavior of the material and thereby obtain the S-N curves and these are used to construct the diagrams of living constant. However, these diagrams, when constructed with small amounts of S-N curves underestimate or overestimate the actual behavior of the composite, there is increasing need for more testing to obtain more accurate results. Therewith, , a way of reducing costs is the statistical analysis of the fatigue behavior. The aim of this research was evaluate the probabilistic fatigue behavior of composite materials. The research was conducted in three parts. The first part consists of associating the equation of probability Weilbull equations commonly used in modeling of composite materials S-N curve, namely the exponential equation and power law and their generalizations. The second part was used the results obtained by the equation which best represents the S-N curves of probability and trained a network to the modular 5% failure. In the third part, we carried out a comparative study of the results obtained using the nonlinear model by parts (PNL) with the results of a modular network architecture (MN) in the analysis of fatigue behavior. For this we used a database of ten materials obtained from the literature to assess the ability of generalization of the modular network as well as its robustness. From the results it was found that the power law of probability generalized probabilistic behavior better represents the fatigue and composites that although the generalization ability of the MN that was not robust training with 5% failure rate, but for values mean the MN showed more accurate results than the PNL model

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We present two models of blocks made of composite material obtained from the use of cement, plaster, EPS crushed, shredded tire, mud, sand and water, for the construction of popular housing. Were made metal molds for the manufacture of blocks to be used in the construction of a residence for low-income families. Performed tests of compressive strength of the composite for various formulations that met the specific standard for blocks used in construction. To study the thermal conductivity of the composite for further study of thermal comfort generated in a residence built with the proposed composite. We also determined the mass-specific and water absorption for each formulation studied. Using a home already built with another composite material, made up the closing of a window with the building blocks and found the thermal insulation, measuring external and internal temperatures of the blocks. The blocks had made good thermal insulation of the environment, resulting in differences of up to 12.6°C between the outer and inner faces. It will be shown the feasibility of using composite for the end proposed and chosen the most appropriate wording

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The so-called "residential tourism" came to intensify the previous occupation of the coastal zones, characterized by traditional beach houses, and brought significant consequences for their spatial configuration, and especially for its scenic value of the landscape. Although there is the intention to regulate the activities of enterprising groups by some legal instruments to control the use and occupation of land, and to contain some negative effects, the actions of government are still inefficient in trying to follow the implications on the landscape from the accelerated growth of the real estate and touristic sectors. Supported in the speech of economic development and income generation, public managers prioritize areas to attract tourists to the detriment of preserving important physical attributes of the natural environment that contribute significantly to the quality of life. The result can be noticed in the use of natural elements as one of the major components in the land valorization, and in the immediate attraction of investors and enterprising. Therefore, the objective of this work is to contribute to the debate on the landscape preservation a little detailed thematic in view of their relevance in the current context - by indicating subsidies to the creation of a methodology for the evaluation and protection of coastal zones that may assist the government in creating new instruments, and better prepare it in control of the occupation of these areas. For such, was followed two ways to analysis: the indirect method and the direct method. The first is grounded in the evaluation of landscape attributes, which is based on the work of Raquel Tardin (2008) and Eduardo Cuesta, Encarnación Algarra and Isabel Pastor (2001). The second, based on the research of Leticia and Carlos Hardt (2010) and on the concepts of phenomenology - expressed by Antonio Christofoletti (1985) and Yi-Fu Tuan (1983) - considers the population perspective on the quality of the natural scenery. Developed through cartographic materials, photographic collections and quantitative tables, this dissertation utilized as a case study the beaches of Barra de Tabatinga and Camurupim, located in the city of Nísia Floresta/RN. Despite already being sighted spaces of advanced stage of landscape degradation in these locations, areas of remarkable scenic value can still be found, what reinforce the urgency in adopting preservationists actions. The absence of laws focused on the management and protection of the landscape singularities associated with the inefficiency of the government to invigilate the land occupation in coastal zones, encourage the excessive action of the real estate-tourism, and consequently make the government the main responsible for the environmental and landscape impacts in these areas - by its omission or by their connivance. Therefore, the legislation permeates this entire process and constitutes itself as the most effective way to guarantee the right to the landscape to present and future generations. Are also pointed some important considerations to build a methodology, especially concerning possibilities of improvements and adaptations of its applicability in each case

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This study has the purpose of investigating the term reader-creator , on the textual aspects of the dramatical works A Morte nos Olhos , A Memória Ferida and Na Outra Margem (2010) by Antonia Pereira Bezerra. In this sense, we propose an analysis of these works based on author‟s life experience as creative matter for a autofictional narrative, highlighting the relations between the autobiographical elements (LEJEUNE, 2008; DOSSE, 2009) and fictional elements in the construction of dramatic narratives. The theoretical analysis pervades the studies fields of Reception Aesthetics (ISER, 1996), memory (RICOUER, 2007) and narrative (RICOEUR, 2010), evidencing the relation between the author and the pursuit of her memories and life experiences, the matter to elaboration of writing. Then we intend thinking a reader-creator of herself, that at the same time she seeks in her memories the biographic aspects to her narrative, she converts this reality with the insertion of fictional elements from the imagination (SARTRE, 2008)

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The Industry of the Civil Construction has been one of the sectors that most contribute to the pollution of the environment, due to the great amount of residues generated by the construction, demolition and the extraction of raw material. As a way of minimizing the environmental impacts generated by this industry, some governmental organizations have elaborated laws and measures about the disposal of residues from the building construction (CONAMA - resolution 307). This work has as objective the reutilization of residues compound of sand, concrete, cement, red bricks and blocks of cement and mortar for the production of red ceramic, with the objective of minimizing costs and environmental impacts. The investigated samples contained 0% to 50% of residues in weight, and they were sintered at temperatures of 950°C, 1000°C, 1050°C, 1100°C and 1150°C. After the sinterization, the samples were submitted to tests of absorption of water, linear retraction, resistance to bending, apparent porosity, specific density, XRD and SEM. Satisfactory results were obtained in all studied compositions, with the possible incorporation of up to 50% of residues in ceramic mass without great losses in the mechanical strength, giving better results to the incorporation of 30% of residues in the fabrication of ceramic parts, such as roofing tiles, bricks masonry and pierced bricks

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Current environmental concerns include the excessive consumption and inefficient use of non-renewable natural resources. The construction industry is considered one of the largest consumers of natural raw materials, significantly contributing to the environmental degradation of the planet. The use of calcareous quarry (RPPC) and porcelain tile polishing residues (RPP) as partial replacements of the cement in mortars is an interesting alternative to minimize the exploration of considerably large amounts of natural resources. The present study aimed at investigating the properties of fresh and hardened mortars produced using residues to replace cement. The residues used were fully characterized to determine their specific mass, unitary mass, particle size distribution and morphology, and composition. The performance of the mortars was compared to that of reference compositions, prepared without residues. A total of 18 compositions were prepared, 16 using residues and 2 reference ones. The mortars were prepared using Portland CP II F 32 cement, CH I hydrated lime, river sand and tap water. The compositions of the mortars were 1:1:6 and 1:0.5:4.5 (vol%), and water to cement ratios of 1.87 and 1.45 were used, respectively. The mortars in the fresh state were evaluated by consistency index, water retention, density of mass and incorporated air content tests. In their hardened state, the mortars were evaluated by apparent mass density, modulus of elasticity, flexural tensile strength, compressive strength and water absorption by capillarity. The mortars were also analyzed by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and fluorescence. Finally, they were classified according to NBR 13281 standards. The mortars prepared using residues partially replacing the cement exhibited lower modulus of elasticity compared to the reference compositions, thus improving the performance in their intended use. On the downside, the water absorption by capillarity was affected by the presence of residues and both the tensile and compressive strength were reduced. However, from the overall standpoint, the replacement of cement by calcareous quarry or porcelain tile polishing residues did not result in significant changes in the properties of the mortars. Therefore, compositions containing these residues can be used in the construction industry

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The system built to characterize electrodes and, consequently, deposited fine films are constituted by a hollow cathode that works to discharges and low pressures (approximately 10-3 to 5 mbar), a source DC (0 to 1200 V), a cylindrical camera of closed borossilicato for flanges of stainless steel with an association of vacuum bombs mechanical and spread. In the upper flange it is connected the system of hollow cathode, which possesses an entrance of gas and two entrances for its refrigeration, the same is electrically isolated of the rest of the equipment and it is polarized negatively. In front of the system of hollow cathode there is a movable sample in stainless steel with possibility of moving in the horizontal and vertical. In the vertical, the sample can vary its distance between 0 and 70 mm and, in the horizontal, can leave completely from the front of the hollow cathode. The sample and also the cathode hollow are equipped with cromel-alumel termopares with simultaneous reading of the temperatures during the time of treatment. In this work copper electrodes, bronze, titanium, iron, stainless steel, powder of titanium, powder of titanium and silício, glass and ceramic were used. The electrodes were investigated relating their geometry change and behavior of the plasma of the cavity of hollow cathode and channel of the gas. As the cavity of hollow cathode, the analyzed aspects were the diameter and depth. With the channel of the gas, we verified the diameter. In the two situations, we investigated parameters as flow of the gas, pressure, current and applied tension in the electrode, temperature, loss of mass of the electrode with relationship at the time of use. The flow of gas investigated in the electrodes it was fastened in a work strip from 15 to 6 sccm, the constant pressure of work was among 2.7 to 8 x 10-2 mbar. The applied current was among a strip of work from 0,8 to 0,4 A, and their respective tensions were in a strip from 400 to 220 V. Fixing the value of the current, it was possible to lift the curve of the behavior of the tension with the time of use. That curves esteem in that time of use of the electrode to its efficiency is maximum. The temperatures of the electrodes were in the dependence of that curves showing a maximum temperature when the tension was maximum, yet the measured temperatures in the samples showed to be sensitive the variation of the temperature in the electrodes. An accompaniment of the loss of mass of the electrode relating to its time of use showed that the electrodes that appeared the spherical cavities lost more mass in comparison with the electrodes in that didn't appear. That phenomenon is only seen for pressures of 10-2 mbar, in these conditions a plasma column is formed inside of the channel of the gas and in certain points it is concentrated in form of spheres. Those spherical cavities develop inside of the channel of the gas spreading during the whole extension of the channel of the gas. The used electrodes were cut after they could not be more used, however among those electrodes, films that were deposited in alternate times and the electrodes that were used to deposit films in same times, those films were deposited in the glass substrata, alumina, stainless steel 420, stainless steel 316, silício and steel M2. As the eletros used to deposit films in alternate time as the ones that they were used to deposit in same times, the behavior of the thickness of the film obeyed the curve of the tension with relationship the time of use of the electrode, that is, when the tension was maximum, the thickness of the film was also maximum and when the tension was minimum, the thickness was minimum and in the case where the value of the tension was constant, the thickness of the film tends to be constant. The fine films that were produced they had applications with nano stick, bio-compatibility, cellular growth, inhibition of bacterias, cut tool, metallic leagues, brasagem, pineapple fiber and ornamental. In those films it was investigated the thickness, the adherence and the uniformity characterized by sweeping electronic microscopy. Another technique developed to assist the production and characterization of the films produced in that work was the caloteste. It uses a sphere and abrasive to mark the sample with a cap impression, with that cap form it is possible to calculate the thickness of the film. Through the time of life of the cathode, it was possible to evaluate the rate of waste of its material for the different work conditions. Values of waste rate up to 3,2 x 10-6 g/s were verified. For a distance of the substratum of 11 mm, the deposited film was limited to a circular area of 22 mm diameter mm for high pressures and a circular area of 75 mm for pressure strip. The obtained films presented thickness around 2,1 µm, showing that the discharge of arch of hollow cathode in argon obeys a curve characteristic of the tension with the time of life of the eletrodo. The deposition rate obtained in this system it is of approximately 0,18 µm/min

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Pastas a base de cimento Portland são utilizadas na cimentação de poços de petróleo. Elas consistem de uma mistura de partículas sólidas de cimento dispersas em água e aditivos. Atualmente, diversos materiais alternativos são utilizados como aditivos, objetivando a modificação e a melhoria das propriedades das pastas de cimento, especialmente no aumento da fluidez. Novos aditivos plastificantes são capazes de suportar as diversas condições de poços, promovendo propriedades no estado fluido compatíveis às condições exigidas para cimentação.Dispersantes são os componentes da pasta que garantem fluidez, além de proporcionar controle na água perdida por filtração na formação porosa, garantindo o sucesso da operação de bombeio. Em deter minados campos, além do efeito da profundidade, as condições geológicas das formações promovemvariações do gradiente de pressão e temperatura ao longo da profundidade vertical do poço. Recentemente, diversos aditivos químicos da indústria da construção civil tem sido estudados em condições de cimentação de poços de petróleo. Vários produtos testados tem apresentado desempenho superior aos produtos normalmente empregados pela indústria de petróleo com boa relação custo/benefício em função do volume de mercado da construção civil. Resultados promissores na seleção de aditivos com função dispersante da construção civil para operações de cimentação de poços de petróleo onshore foram obtidos para temperaturas até 80°C. O potencial de uso desses aditivos permite estabelecer novas soluções para problemas encontrados na cimentação de poços de petróleo HPHT, poços sujeitos à injeção de vapor, poços depletados e poços produtores de gás. Na construção civil, os superplastificantes permitem reduzir o fator água/cimento das argamassas proporcionando melhoria de propriedades como resistência mecânica e fluidez. Assim, o objetivo deste trabalho foi o estudo e a caracterização reológica de pastas constituídas de cimento Portland, água e aditivos do tipo plastificante, com função dispersante a base de naftaleno condensado e policarboxilato, na faixa de temperaturas de 58°C e 70ºC. As condições utilizadas para a avaliação dos aditivos alternativos foram baseadas em uma cimentação primária para um poço hipotético de 2200 m de profundidade e gradientes geotérmicos de 1,7°F/100 pés e 2,1°F/100 pés. Os resultados demonstraram a grande eficiência e o poder dispersivo do policarboxilato para as temperaturas estudadas. O aditivo promoveu alta fluidez, sem efeitos de sedimentação da pasta. O dispersante à base de naftaleno reduziutant o a viscosidade plástica como o limite de escoamento acimada concentração a partir de 0,13%. O modelo de Bingham descreveu bem o comportamento reológico das pastas com policarboxilato para todas as concentrações

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The technique of surface coating using magnetron sputtering is one of the most widely used in the surface engineering, for its versatility in obtaining different films as well as in the micro / nanometric thickness control. Among the various process parameters, those related to the active species of the plasma are of the most fundamental importance in the mechanism and kinetics of deposition. In order to identify the active species of the plasma, parameters such as gas flow, pressure and density of electric power were varied during titanium coating on glass substrate. By flowing argon gas of 10, 20, 30, 40 and 50 sccm (cubic centimeters per minute) for each gas flow a sequential scan of the electric current of 0.10, 0.20, 0.30, 0.40 , 0.50 A. The maximum value of 0.50 A was chosen based both on literature data and on limitations of the equipment. The monitoring of plasma species present during the deposition was carried out in situ by the technique of optical emission spectroscopy (OES) through the spectrometer Ocean Optics USB2000 Series. For this purpose, an apparatus was developed to adapt the OES inside the plasma reactor to stay positioned closest to the target. The radiations emitted by the species were detected by an optical fiber placed behind the glass substrate and their intensities as a function of wavelength were, displayed on a monitor screen. The acquisition time for each condition of the plain parameters was related to the minima of spectral lines intensities due to the film formed on the substrate. The intensities of different emission lines of argon and titanium were then analyzed as a function of time, to determine the active species and estimate the thickness of the deposited films. After the deposition, the coated glasses thin films were characterized by optical transmittance through an infrared laser. It was found that the thickness and deposition rate determined by in situ analysis were consistent with the results obtained by laser transmittance

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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The companies are part of an important segment of the society, besides, it exercises a significant contribution, being also responsible for helping in the improvement of the quality of life of the population. Like this being, to present research looked for to investigate the perception that the entrepreneurs of the building site of Aracaju/SE have concerning the theme Business Social Responsibility (RSE). besides the perceptions, it was part also of the research, to know the entrepreneur's of the building site social construction and the possible practices of Social Responsibility. The research grew in two different moments. The first looked for the theoretical embasamento, trying to study the economical sociology, understanding the effects provoked by the economy, understanding to you reason them that you/they took to the appearance of the perceptions that you/they permeate the historicity among the market, the nascedouro of the associations as company and his/her dynamics in the society. It was also researched, the concept of social responsibility in national and local extent, as well as, the contextualização of the state of Sergipe, detaching the municipal district of Aracaju, and describing how it happened his/her development starting from what is considered urbanization. In the second moment, the accomplishment of interviews in five companies, allowed to notice the entrepreneurs' perception concerning business social responsibility, as well as, actions of different characteristics in four of the samples. In these actions, they are patronage in cultural events, donations of projects for charity institutions, the concern with the preservation of the environment in the use of work materials ecologically correct, preventive health and employees' training. Concluding the research, I introduce the conclusions which it allowed to arrive me, and I point some suggestions for future researches that enlarge the reflection on this theme

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Ce travail que nous venons de présenter apport une systématisation sur la viabilité de la praxis de l´éducateur français Célestin Freinet (1896-1996). Il s´agit d´une étude qualificative, recherche-action, développée dans une école coopérative l´ École Freinet à Natal/RN Brésil, auprès des élèves du 5ème et 8ème séries de l´Enseignement Fondamental. Le problème central que nous a amené à cette recherche, a été le fait de vérifier les progressions dans la production scientifique et dans les pratiques des enseignants qui ont à la charge l´Éducation Infantine et les premières séries de l´Enseignement Fondamental. Tout cela en tenant compte en concevoir l´élève en tant que sujet actif de son apprentissage et coresponsable à l´organisation du travail scolaire. Toutefois, qaund-il s´agit des quatre dernières séries de l´Enseignement Fondamental (5ème au 8ème séries), les propositions progressistes sont prises comme quelque chose pratiquement impossible d´en mettre en marche. Pour attenuer la lacune théorique sur le sujet, nous avons offert un texte significatif pour les enseignants d´une façon générale, les chercheurs de l´académie et pour l´écolechamp de la recherché. Tout cela par le fait de ne pas donner de priorité à une technique ou à un principe, en particulier. Cette pédagogie est discutée autant que possible dans son contexte global et aussi sur le comment s´est manifestée dans sa práxis . Nous avons mis en relief les aspects importants pour le fonctionnement de la salle de classe, aussi que les estratégies utilisées pour la construction, communication et documentation des connaissances L´intervention nous a permis de construire l´objet par la réflexion en action, à partir des données obtenues pendant les observations, les entretiens, les enterviews, les moments d´études et de la quête des textes écrits. L´analyse a été faite à la lumière de la methodologie comprehensive (Kaufmann, 1996), entrelacée au materiau empirique et à la théorie. Cette forme d´analyse nous a permis d´obtenir la logique dans l´ensemble comme nous crayons que doit caracteriser la recherche aux Sciences Humaines et Sociales. Les considérations finales mettent l´accent d´un côté sur l´efficacité de la pédagogie Freinet, pour orienter le processus de l´enseignement apprentissage, en tous les dégres de l´enseignement et de l´autre côté nous montre la nécessité urgente de l´équipe de l´école champ de la recherche, de qualifier sa pratique à partir des références théoriques-pratiques de la pédagogie Freinet