Estudo sobre as potencialidades de compósitos à base de gesso e fibras de coco seco para aplicação na construção civil

The use of gypsum, one of the oldest building materials for the construction industry in the country has been experiencing a significant and steady growth, due to its low cost and some of its properties that confer comparative advantage over other binder materials. Its use comprises various applications including the coating of walls and the production of internal seals and linings. Moreover, the fibers are being increasingly incorporated into arrays fragile in an attempt to improve the properties of the composite by reducing the number of cracks, the opening of the same and its propagation velocity. Other properties, depending on the function of the component material or construction, among these thermal and acoustic performances, are of great importance in the context of buildings and could be improved, that is, having better performance with this embodiment. Conduct a comparative study of physico-mechanical, thermal and acoustic composite gypsum incorporating dry coconut fiber, in the form of blanket, constituted the main objective of this work. Improving the thermal and acoustic performances of precast gypsum, used for lining and internal vertical fences of buildings, was the purpose of development of these composites. To evaluate the effect of fiber content on the properties of the composites were used to manufacture the composite layer with different thicknesses. The composites were fabricated in the form of plates with dimensions of 500x500x24mm. To facilitate the comparative study of the properties were also made with material gypsum boards only. We then determined the physico-mechanical, thermal and acoustical plaster and composites. The results indicated that the composites were significant gains in relation to thermal performance and also acoustic, in certain frequency range, increasing the thickness of the blanket. Concerning other physical-mechanical properties, the results showed that although the compressive strength was lower than for the composite did not occur after a fracture catastrophic failure. The same trend was observed with regard to resistance to bending, since the composites have not suffered sudden rupture and still continued after the load supporting point of maximum load

Alternativas de ultimação de resíduo plástico termofixo

In the present work it was developed originals alternatives of enveronmentally safe and economically viable destination of thermoset plastic residue from a button factory, which at presnte stores such residue tempor and in a way that is inconvenient to the atmosphere, a waiting safe solutions. As the residue is not recycleab and its burning leberates strongly aggressive gases, safe alternatives were researched. Inicially, ghe residue in incineration was performed in cement ovens with precise control ofe emission of gases, but it was proved inviable due to its low calorific power, as well as the liberation of free lead in the ashes. An original and feasible option was the residue confinemente in soil-ciment blocks, lohich resulted in blocks highly resistant to simple compression with structural block, and also a significant increase in thermal resistence. Was got up other options of original and important composites as: making of blocks for pré-moulded flagstone, internal coating of walls with plaster being obtained good texture results, replenish of ceramic blocks and blocks with cement, also implying in increase of thermal resistance. Besides these original and scientific contributions, the it was technologically contribution of defreadation with suggestions of the material using torch of thermal plasm; for this was projected, built, characterized and tested a torch to it shapes it being obtained exciting results for the development of this technology come back for ending destruction from all the types of inconvenient garbage to the atmosphere

Comportamento de adesão da madeira de um híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis proveniente de três condições de manejo

This study aimed to evaluate the adhesion ability of eucalyptus lumber from three tillage systems, using adhesives: resorcinol formaldehyde and two adhesives in water emulsion based on vinyl poly-acetate. The management systems were characterized by three strata, the stratum one (E1) characterized by wood from coppice and 70 months of age, the stratum two (E2) characterized by wood and retirement age of 166 months and stratum three (E3), also characterized by retirement at 70 months of age. The wood was derived from a random mixture of the first two sawn logs, each three feet from the base, which comprised three treatments on the adhesive used. We evaluated the shear strength by compression tests and the percentage of wood failure in the glue line. Based on the results obtained, it can be said that the adhesion had satisfactory performance with all the resins used, and the average values of shear strength of the glue line were shown to be equivalent to the shear strength of solid wood only for the samples which adhered with 'Wonderbond' adhesive and also provide higher values for wood failure (97.64%). The highest density present in the wood of the second stratum (E2) influenced only sticking with the resorcinol formaldehyde resin. For polyvinyl acetate (Cascorez 2590), shear values decreased in the third management condition (E3).

CAD e engenharia reversa como ferramentas de auxílio na fabricação de cartuchos para próteses ortopédicas

The manufacturing of above and below-knee prosthesis starts by taking surfac measurements of the patient s residual limb. This demands the making of a cartridg with appropriate fitting and customized to the profile of each patient. The traditiona process in public hospitals in Brazil begins with the completion of a record file (according to law nº388, of July 28, 1999 by the ministry of the health) for obtaining o the prosthesis, where it is identified the amputation level, equipment type, fitting type material, measures etc. Nowadays, that work is covered by the Brazilian Nationa Health Service (SUS) and is accomplished in a manual way being used commo measuring tapes characterizing a quite rudimentary, handmade work and without an accuracy.In this dissertation it is presented the development of a computer integrate tool that it include CAD theory, for visualization of both above and below-knee prosthesis in 3D (i.e. OrtoCAD), as well as, the design and the construction a low cos electro-mechanic 3D scanner (EMS). This apparatus is capable to automatically obtain geometric information of the stump or of the healthy leg while ensuring smalle uncertainty degree for all measurements. The methodology is based on reverse engineering concepts so that the EMS output is fed into the above mentioned academi CAD software in charge of the 3D computer graphics reconstruction of the residualimb s negative plaster cast or even the healthy leg s mirror image. The obtained results demonstrate that the proposed model is valid, because it allows the structura analysis to be performed based on the requested loads, boundary conditions, material chosen and wall thickness. Furthermore it allows the manufacturing of a prosthesis cartridge meeting high accuracy engineering patterns with consequent improvement in the quality of the overall production process

Estudo da Potencialidade da produção de tijolos de adobe misturado com outros materiais: uma alternativa de baixo custo para a construção civil

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

Projeto, construção e análise de desempenho de um forno solar alternativo tipo caixa a baixo custo

An alternative box-type solar oven constructed from the scrap iron of a gas conventional cook is presented, which functions principles are the effect greenhouse and the concentration. The oven of the conventional cook is the baking enclosure where the absorber (pot) of the solar oven is located, being re-covered for a glass blade for the generation of the greenhouse effect isolated lateral and having deep its and for a composite the plaster base and EPS. Segments of plain mirrors had been placed in the laterals of the oven for the concentration of the radiation and a reflecting parabola was introduced in the baking enclosure for the exploitation of the incident reflected radiation in the interior of the oven. The oven is mobile to allow one better aiming of exactly in relation to the apparent movement of the sun. The thermal economic and of materials viabilities of the stove in study will be demonstrate The average internal temperature of the absorber was around 150°C and the internal temperature around 120°C. Will demonstrate that its low cost and good thermal performance represents basic characteristics for the viability of large use of such archetype, mainly for cooking the decreases and averages temperatures. One will reveal that the archetype in study is competitive with the box-type solar cooker conceived in the whole world

Construção e análise de desempenho de um forno/fogão solar tipo caixa construído a partir de uma sucata de pneu

An alternative box-type solar cooker built starting from the scrap of a tire and a scrap of old office chair is presented, which principles functions are the effect greenhouse and the concentration. The tire served as structure for making of is the baking enclosure where the absorber (roasting pan 20x30cm) of the solar is located, being re-covered for a glass blade for the generation of the greenhouse effect isolated lateral and having deep its and for a composite the plaster base and EPS. Segments of plain mirrors had been placed in the laterals of the oven/cook for the concentration of the radiation and a reflecting parable was introduced in the baking enclosure for the exploitation of the incident reflected radiation inside of the oven/cook. The oven/cook is mobile to allow one better aiming of exactly in relation to the apparent movement of the sun. The thermal economic and of materials viabilities of the stove/cook in study will be demonstrate. The average internal temperature of the absorber was around 152,3°C and the internal temperature around 110°C. Will demonstrate that toits low cost and good thermal performance, represents basic characteristics for the viability of large use of such archetype, mainly for cooking the decreases and averages temperatures. One will reveal that the archetype in study is competitive with the box-type solar cooker conceived in the whole world

Estudo térmico e de materiais na construção de casas populares com blocos confeccionados a partir de um composto a base de cimento, gesso, eps e raspa de pneu

We built an experimental house on an UFRN´s land using blocks made by a composite consisting of cement, plaster, EPS, crushed rubber and sand. Several blocks were made from various compositions and we made preliminary tests of mechanical and thermal resistance, choosing the most appropriate proportion. PET bottles were used inside the block to provide thermal resistance. In this work, a second function was given to the bottles: to serve as a docking between the blocks, because the ends of the cylinders came out of each block on top as well as at the bottom, with the bottom cut, allowing to fit of the extremities of the upper cylinder of a block in the lower holes of the other one, which were formed by the cutting already mentioned. Minimum compression tests were performed according to ABNT standards for walls closing blocks (fence). With that house built, we did studies of thermal performance in order to ascertain conditions of comfort, checking external and internal temperatures in the walls and in the ambient, among other variables, such as wind speed and relative humidity. The resulting blocks provided adequate thermal insulation to the environment, where the walls presented differences up to 11.7 ºC between the outer and inner faces, getting the maximum temperature inside the house around 31 °C, within the so-called thermal comfort zone for warm climates. At the end of the experiments it was evident the effectiveness of that construction in order to provide thermal comfort in the internal environment of the house, as well as we could confirm the viability of building houses from recyclable materials, reducing the constructive costs, becoming a suitable alternative for low- incoming families. Moreover, besides the low cost, the proposal represents an alternative use of various recyclable materials, therefore considered an ecological solution

Nota sobre a biologia de "Microdon tigrinus" (Diptera: Syrphidae), parasito social de "Acromyrmex coronatus" (Hymenoptera: Formicidae)

The fly of the syrphid Microdon tigrinus is a specific social parasite of leaf-cutting ant, Acromyrmex coronatus. Six colonies of Acromyrmex coronatus were collected in plastic containers, which there was a layer of 1 cm of plaster, with the purpose of maintaining the humidity of fungus culture. Larvae of social parasite were separate for the establishment of instars number, through morphometric study. The data were measured of 165 larvae, using spiracle (length (Ls), width (Ws) and distance between spiracle (Ds)). After that, the morphometric data obtained for the larvae were submitted to cluster analysis by Wong's hybrid method, which produces the adequate number of groups through pseudo F-statistics and pseudo t-squared statistics. The three morphometric variables studied permitted grouping of larvae into the following three distinct groups: cluster 1 [long dash] consisting of 55 larvae (Ls=0.177[plus or minus]0.026, Ws=0.163[plus or minus]0.030, Ds=0.052[plus or minus]0.008 mm); cluster 2 - consisting of 20 larvae (Ls=0.631[plus or minus]0.065, Ws=0.630[plus or minus]0.049, Ds=0.065[plus or minus]0.018 mm); cluster 3 - consisting of 90 larvae (Ls=1.294[plus or minus]0.062, Ws=1.308[plus or minus]0.069, Ds=0.140[plus or minus]0.018 mm). of the all couples, only 1 obtained success in the mating, and the female, after 24 hours, began the oviposition. The female layed 76 eggs in a period of 6 days, after that, her death. The larvae emerged in the seventh day (incubation period [plus or minus] 7 days). From 76 eggs, 54 were viable, with a viability of 71.05%. This study contributes to the knowledge of Microdon tigrinus biology of, a social parasite poorly studied in Brazil.

Análise de desempenho de um fogão solar com parabola fabricada em material compósito

It is presented a solar cooker made with a parabolic reflector composed by a composite material. For this purpose, it was utilized a cast concrete with a parabolic profile obtained by means of modeling. It will be demonstrated the manufacturing process and settings, as well as tests results, in order to determine the contact temperature and cooking time of some foods. This solar cooker presents the following main characteristics: the concentration method, low cost and easy manufacturing process. It was performed by employing recycled materials such as cement, plaster, crushed polystyrene and wheels. The captation area measures 1 square meter and its parabole was covered with a mirrors measuring 25 cm2. A temperature higher than 650°C was obtained. Furthermore, it has been demonstrated that the cooking viability for several type of foods such as beans, potatoes, rice, yams and pasta can be used in two meals for a family of four. In addition, the advantages of this cooker were analysed in comparison with others described in literature as well as those operating on gas. Especially in Northeast of Brazil, where there is a potential for solar energy, this prototype is an important tool, because it avoids not only desertification, but also pollutants from burning firewoods which cause ecological imbalance

Compósito para fabricação de blocos para construção de casas: estudos térmico e de materiais

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

Análise térmica e mecânica de um compósito de matriz cerâmica com carga de EPS e raspa de pneu para construção de casas populares

Space Science was built using a composite made of plaster, EPS, shredded tires, cement and water. Studies were conducted to thermal and mechanical resistance. Inside the mold EPS plates were placed in order to obtain a higher thermal resistance on the wall constructed, as well as to give it an end environmentally friendly in view of both the tire and the EPS occupy a large space in landfills and year need to be degraded when released into the environment. Compression tests were performed according to ABNT blocks to seal, measurements of the temperature variation in the external and internal walls using a laser thermometer and check the temperature of the indoor environment using a thermocouple attached to a digital thermometer. The experiments demonstrated the heat provided by the composite values from the temperature difference between the internal and external surfaces on the walls, reaching levels of 12.4 ° C and room temperature in the interior space of the Science of 33.3 ° C, remaining within the zone thermal comfort for hot climate countries. It was also demonstrated the proper mechanical strength of such a composite for sealing walls. The proposed use of the composite can contribute to reducing the extreme housing shortage in our country, producing popular homes at low cost and with little time to work

Viabilidade de utilização de um compósito de matriz cerâmica com cargas recicláveis na fabricação de equipamentos solares

Composite materials can be defined as materials formed from two or more constituents with different compositions, structures and properties, which are separated by an interface. The main objective in producing composites is to combine different materials to produce a single device with superior properties to the component unit. The present study used a composite consisting of plaster, cement, EPS, tire, PET and water to build prototype solar attempt to reduce the manufacturing cost of such equipment. It was built two box type solar cookers, a cooler to be cooled by solar energy, a solar dryer and a solar cooker concentration. For these prototypes were discussed the processes of construction and assembly, determination of thermal and mechanical properties, and raising the performance of such solar systems. Were also determined the proportions of the constituents of the composite materials according to specific performance of each prototype designed. This compound proved to be feasible for the manufacture of such equipment, low cost and easy manufacturing and assembly processes

Estudo de um isolante térmico para tubos fabricado em material compósito

It presents a new type of insulation for ductwork hot water, which can be used in solar systems for heating water, which consists of a composite of different compositions based on plaster, cement and EPS ground, palm and water. This composite has as its main features easy assembly and manufacturing processes and low cost. Comparative results will be presented on the tests of materials and thermal tubes proposed. Four formulations were used to manufacture tubes with three diameters 70, 65 and 42mm. It was also tested conventionally used for elastomeric foam insulation to 110 ° C, for a comparative analysis with the composite pipe insulator proposed. It will demonstrate that the cost of manufacturing of such tubes is competitive with alternative elastomeric foam tested, but results of the composite tube to the temperature range studied, are lower. Another drawback of the composite insulator tube is its large mass. It would be important to test such a composite for greater levels of temperature to a diagnostic technique competitive with conventionally used insulators. A positive factor of using the proposed composite-tube would be the recycling of EPS so damaging to the environment, representing an environmentally friendly application of science

Otimização do tempo e temperatura no processamento da gipsita oriunda dos cristalizadores da produção de sal para obter gesso de uso na construção civil

During the process of the salt production, the first the salt crystals formed are disposed of as industrial waste. This waste is formed basically by gypsum, composed of calcium sulfate dihydrate (CaSO4.2H2O), known as carago cru or malacacheta . After be submitted the process of calcination to produce gypsum (CaSO4.0,5H2O), can be made possible its application in cement industry. This work aims to optimize the time and temperature for the process of calcination of the gypsum (carago) for get beta plaster according to the specifications of the norms of civil construction. The experiments involved the chemical and mineralogical characterization of the gypsum (carago) from the crystallizers, and of the plaster that is produced in the salt industry located in Mossoró, through the following techniques: x-ray diffraction (XRD), x-ray fluorescence (FRX), thermogravimetric analysis (TG/DTG) and scanning electron microscopy (SEM) with EDS. For optimization of time and temperature of the process of calcination was used the planning three factorial with levels with response surfaces of compressive mechanical tests and setting time, according norms NBR-13207: Plasters for civil construction and x-ray diffraction of plasters (carago) beta obtained in calcination. The STATISTICA software 7.0 was used for the calculations to relate the experimental data for a statistical model. The process for optimization of calcination of gypsum (carago) occurred in the temperature range from 120° C to 160° C and the time in the range of 90 to 210 minutes in the oven at atmospheric pressure, it was found that with the increase of values of temperature of 160° C and time calcination of 210 minutes to get the results of tests of resistance to compression with values above 10 MPa which conform to the standard required (> 8.40) and that the X-ray diffractograms the predominance of the phase of hemidrato beta, getting a beta plaster of good quality and which is in accordance with the norms in force, giving a by-product of the salt industry employability in civil construction