1000 resultados para CNPQ::ENGENHARIAS::ENGENHARIA CIVIL::CONSTRUCAO CIVIL
Resumo:
With a view to revitalizing public environments through criteria that include economy, tourism, aesthetics and respect for the environment, this paper proposes a model of kiosk manufactured with composite material blocks, to be employed as a public instrument. . The model consists of a structure composed of planned blocks and manufactured in cement-based composite, gypsum, ground and water, having the styrofoam inside filled with pet bottles of 500 ml dose. The social and environmental issue is the critical point of the work when it can, through the reuse of environmentally harmful materials such as polyethylene terephthalate PET, using such modules for the construction of various areas of Commerce, promoting the protection of the environment combined with the improvement of the quality of life of the population. The tourism factor, which is significant in the economy of the North, is also considered as the modulated kiosk has a visual aspect innovative and differentiated. The environmental issue is addressed by encouraging the reuse of PET material and EPS (polystyrene)
Resumo:
In recent decades, ceramic products have become indispensable to the technological development of humanity, occupying important positions in scientific production and consequently in industrial production. One area of the economy that continues to absorb large amounts of the products of this sector is Construction. Among the branches of the ceramic industry, there are the red ceramic industry which is traditionally the basis of that economic sector. Among the reasons for which the red ceramic industry became popular in the country, and specifically in Rio Grande do Norte, is the abundance of this raw material, easily found throughout the national territory. However, it appears that the red ceramic industry has deficiencies in technology and skilled labor, resulting in the production of ceramic goods with low added value. Among the factors that determine the quality of the ceramic products red has the proper formulation of the ceramic mass, the conformation and the firing temperature. Thus, the overall goal of this work is to study the mineralogical and technological properties, two clays from the region of the Wasteland Potiguar industrial ceramist. Therefore, the raw materials were characterized by analysis of Xray diffraction (XRD) analysis, X-ray fluorescence (XRF), particle size analysis (FA), scanning electron microscopy (SEM), optical microscopy (OM ), plasticity index (PI), thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). The technological properties of the material were analyzed by water absorption tests (AA%) porosity (% PA), the linear shrinkage (RT%), apparent density (MEA), loss on ignition (PF%) and flexural strength three points (TRF)
Resumo:
Concern for the environment and the exploitation of natural resources has motivated the development of research in lignocellulosic materials, mainly from plant fibers. The major attraction of these materials include the fact that the fibers are biodegradable, they are a renewable natural resource, low cost and they usually produce less wear on equipment manufacturing when compared with synthetic fibers. Its applications are focused on the areas of technology, including automotive, aerospace, marine, civil, among others, due to the advantageous use in economic and ecological terms. Therefore, this study aims to characterize and analyze the properties of plant fiber macambira (bromelia laciniosa), which were obtained in the municipality of Ielmo Marino, in the state of Rio Grande do Norte, located in the region of the Wasteland Potiguar. The characterization of the fiber is given by SEM analysis, tensile test, TG, FTIR, chemical analysis, in addition to obtaining his title and density. The results showed that the extraction of the fibers, only 0.5% of the material is converted into fibers. The results for title and density were satisfactory when compared with other fibers of the same nature. Its structure is composed of microfibrils and its surface is roughened. The cross section has a non-uniform geometry, therefore, it is understood that its diameter is variable along the entire fiber. Values for tensile strength were lower than those of sisal fibers and curauá. The degradation temperature remained equivalent to the degradation temperatures of other vegetable fibers. In FTIR analysis showed that the heat treatment may be an alternative to making the fiber hydrophobic, since, at high temperature can remove the hemicellulose layer, responsible for moisture absorption. Its chemical constitution is endowed with elements of polar nature, so their moisture is around 8.5% which is equivalent to the percentage of moisture content of hydrophilic fibers. It can be concluded that the fiber macambira stands as an alternative materials from renewable sources and depending on the actual application and purpose, it may achieve satisfactory results
Resumo:
The sludge generated in stabilization ponds can be designed for various purposes, among them we mention agricultural use, recovery of degraded areas and civil construction. The choice of these alternatives should be made based on qualitative and quantitative characteristics of the sludge. In this context, this study characterized the digested sludge from an anaerobic lagoon in Cidade do Natal/RN, which deals exclusively with residues of depleted septic tanks and pits. The sludge showed levels of macro and micronutrients that confirm its potential for agriculture, with 139.49 g.kg -1 organic matter, 15.40 g.kg-1 nitrogen and metal concentrations below those required by Resolution No. 375/06 of CONAMA, besides the absence of fecal coliform and less than 0.15 viable helminthes eggs/g, on average. The particle size distribution showed that most of the particles have a diameter similar to the sand, allowing the replacement of this input, for example. Analysis of the leachate and of the sludge solubilized classified as non-inert and non-hazardous according to NBR 10.004/04. The volume produced in three years of operation by the pond was 1903.50m³, equivalent to approximately 400 kg of dry sludge. Overall, the concentrations of the parameters were similar to literature, although none of them addresses sludge anaerobic pond treating sewer from septic tanks and pits.The sludgepresents technical feasibility to various types of use, however the cost of dewatering and especially with transport can derail it. It needs to be made a more thorough study of the costs to prove its economic viability
Resumo:
In Natal/RN, 68% of the population uses some kind of individual system for their domestic sewers treatment, being that the most used it is septic tank, followed by sumidouro. Every treatment system of sewers, usually used, generates a by-product denominated sludge. That residue presents some components, in its constitution, undesirable under the environmental and sanitary point of view. In such case, to assure that the system treatment has satisfactory results, it is necessary to do the adjusted disposition of the sludge sewage. Several countries are looking for technical alternatives for the use and disposition of residues. Under technical and environmental conditions appropriate, these materials can be used, decreasing the consumption of the natural resources and the treatment need, storage or elimination of the wastes, what decrease the risks created. Some of the alternatives of recycling of the sludge sewage are: the application in the agriculture, in the production of energy and as raw material in the civil construction. This study evaluated asphalt mixtures behavior that partially substituted conventional aggregates by septic tank sludge. The septic tank sludge gave origin to two raw materials called raw sludge and sludge ash. The raw sludge was put as a small aggregate and the sludge ash as filler. In the first experiment it was made a comparison between the mixture with conventional aggregates and the mixtures that replaced sand by raw sludge in the proportions from 5% to 40%. In the second experiment, it was made comparison between mixtures with 1%, 2% and 3% of sludge ash and cement. The stages developed along the study were: physical characterization of the conventional materials; physical, chemistry, thermal, mineralogical characterizations and analysis of environmental risk of the raw sludge; physical characterization and analysis of environmental risk of the sludge ash; analysis of the mixtures performance through its volumetric and mechanical characteristics; forecast of the mixtures susceptibility in the moisture presence. For the grain size composition used and with the percentage asphalt adopted, the mixtures with up to 7,5% of raw sludge in his composition attend to the National Department of Transports Infrastructure (DNIT) specifications. However, in agreement with the mixtures susceptibility in the moisture presence, the mixtures with addition of raw sludge don't present satisfactory acting. In such case, they could be used in arid and semi-arid areas. The raw sludge application in mixtures increased their voids volume and their stability. However, it damaged mixtures adhesiveness. Mixtures with sludge ash and with cement presented similar behavior. However, mixtures with sludge ash presented a better performance than mixtures with cement as for their stability and their tensile strength ratio. The mixture with 1% of sludge ash is better. The wastes studied don't represent environmental risk
Resumo:
This work aims to demonstrate the feasibility of a ceramic composite containing fiber in the rubber manufacturing interlocking blocks. Gravel, sand, cement, rubber and fiber: the processes of manufacture and assembly of blocks produced and the various formulations studied with different proportions between the constituent elements were addressed. Mechanical properties were determined for the different formulations, compressive strength, diametral compressive strength, water absorption and apparent density, obeying the rules related to each property. It was concluded that the addition of rubber fiber gave the concrete studied resistance lower than conventional concrete which can be verified on the microstructural analysis obtained by SEM, which revealed the presence of pores and the low adhesion between the fiber and the matrix compression (tire fiber / cement paste). The composite of more viable tire BCPB1 (1/2) fiber can be used in places requests as light squares, pavements, roads and other cycle as well as in the manufacture of the curb and gutter, by having compressive strength in about 20 MPa
Resumo:
Inúmeras estruturas de concreto no Brasil e no mundo estão atingindo o limite de sua vida útil projetada, completando um ciclo de cinco ou mais décadas de uso e operação. Além das estruturas mais antigas, existem ainda estruturas com reduzido tempo de serviço, e qualidade discutível, que já apresentam patologias em estado tão avançado que chegam a comprometer o seu desempenho. Vindo ao encontro dessas necessidades e no sentido de contribuir para o avanço científico e tecnológico do setor, este trabalho apresenta um método para dosagem, preparo e aplicação de argamassas de alto desempenho para recuperação de estruturas deterioradas, além de sugerir procedimentos para a realização desses reparos, fomentando a cultura das manutenções preventivas e desmistificando a complexidade atribuída a tais operações. Para tanto, foram realizados ensaios mecânicos, microestruturais e relacionados à durabilidade em corpos-de-prova moldados com sílica ativa e látex de estireno-butadieno. Os resultados indicaram que a adoção desses ingredientes, na composição da argamassa de reparo, provocou uma redução significativa da permeabilidade total e descontinuidade de poros, assim como promoveu uma melhor integridade dos constituintes da argamassa, traduzindo-se em uma ampliação, expressiva, das suas capacidades mecânicas. Quando comparada aos produtos industrializados da construção civil, com padrões similares, proporcionou uma economia da ordem de 85%, que permitiria recuperar, com os mesmos custos, quase cinco vezes mais estruturas comprometidas. Este estudo, de viés altamente tecnológico, vem oferecer à construção civil uma argamassa polimérica de alto desempenho, com função reparadora e custo mais acessível, que pode ser adotada em canteiros de obras, implementando ações de natureza sustentável e ainda atendendo às atuais exigências elencadas pela literatura, relacionadas à desempenho, vida útil e durabilidade das estruturas reparadas.
Resumo:
Considered as one of the oldest activities done by men, the civil construction represents one of the most important sectors for the economic growth of a country, in spite of the low results of growth in the past few years and also in the current year. To make this industry grow, even with an unfavourable economic scenario, it is necessary to implement an effective planning in its activities. This is one of the most important concepts brought by the Lean Construction philosophy, which had its origin through the adaptation of the concepts established by the Toyota Production System (TPS) or Lean Production. By having as a scenario the city of Natal\RN, the main goal of this dissertation consists in investigating how the 11 principles of the lean construction influenced the schedule of a construction field that started to implement its lean concepts. As a methodology, it was used the case study of a big enterprise located in Natal (RN). During the execution of the method, documents related to the short-term, midterm and long-term planning were analysed , aiming to describe its planning process; it was also described the factors that caused the delays at the enterprises’ field ;in addition, a comparison was made between the results obtained at the case study and the ones presented at the literature; in the end, the actions were listed by the company, which had the purpose to solve the main causes of delays, verifying if they were linked to the lean construction principles. This research finds its reason of existence in the relevance of its theme at the nowadays reality of the construction industry, since the principles of the lean construction uphold the reduction of processes that are useless, diminishing wastes as well as costs in construction. The relevance is perceived for the academy, in terms of the possibility to discuss if the concepts established by the lean production are being adapted to the civil construction sector and how this adaptation is influencing at the buildings planning project. Economic importance, because with the reduction of the wastes and costs, the companies may reduce the building´s value into a more accessible value, even with the sector´s lower growth. And social significance, because lean construction gives a better participation of the labour at the planning activity. Among the main results, the high frequency of planning errors stands out, mainly the programming deviations and not the task programming, as well as the execution errors, low productivity and activities executed by the workers. Amongst the 11 principles of lean construction, only five were related with the 12 actions analysed by the author. From the 12 actions, four were completely cohesive to one or more from these five principles. Some improvement proposals were also highlighted and established by the research.
Resumo:
The final quality of the works accomplished by the building construction industry depends directly on the quality of the materials supplied and used during all their phases of execution. The federal government participation and several state programs have established conditions to stimulate and require the increment of the quality level in the building construction industry´s product chain. These programs aim at the product conformity to the technical standards. Within this context, the evaluation program of the ceramic product conformity in Rio Grande do Norte state is assessing the conformity degree to Brazilian Technical Standards of ceramic bricks and tiles made in the ceramic production area in the state. In this work, is determine the degree of conformity of the sealing ceramic bricks made by some companies in different areas of the state, such as Assú, São Gonçalo do Amarante, Apodi, Parelhas, São José do Mipibu e Macaíba. Using the technical standards as a point of reference, we attempted to reproduce in the laboratory the experimental procedures to the analysis execution, according to the specifications. It was possible to determine that none of the evaluated samples are in strict conformity with the current technical standards, what reflects the real situation of the products available on the market.
Resumo:
Given the growth demand for air transport allied to the need of adequacy of the infrastructure of the airports the need arises for the elaboration and Project Deployment enhancements to to the administrative management with efficiency and effectiveness of processes. The present dissertation aims to develop an organizational and operational proposal to management improvement projects an airport midsize business. The state of art literature contemplated the following topics: project management, project office; improvement approaches; improvement projects and technical and support improvement projects and project management tools. The research method is characterized as a case study of a qualitative nature. The validation of the proposal was carried out through a focus group with the participation twelve representatives of the administrative areas of an airport-sized Brazilian midfielder with the objective of validate the proposed organizational structure and operational procedures and to identify the barriers to implementation of the proposal. The result of the work presents an proposed considering the integration of the project office with the organizational structure of the administration, the conception of the project office, operating procedures and the directives for implementation
Resumo:
The present dissertation aims to analyze the evaluation process of environmental performance inside an organization from the building construction section of civil construction based on the NBR ISO 14031 guidelines, which provide orientation regarding the implementation of this project towards the internal organizational management. The theoretical research has addressed concepts and historical development of environmental management inside organizations, from the emergence of the first models to the strengthening of environmental management through the standardization of the Environmental Management System caused by the publication of ISO 14001. It has also addressed the evaluation of environmental performance, the NBR ISO 14031 (concepts, types of indicators of evaluation of environmental performance, the elaboration process of such indicators, as well as its use and evaluation by the high administration). The research has an applied character, with exploratory and descriptive goals, and a qualitative approach based on case study. The data collection will be made through questionnaires, interviews, and documental analysis. Through the present research project, one expects to learn the elements taken into consideration by the organization for the elaboration and selection of indicators; to identify which interested parties contribute in the aforementioned process; to discover which sources are taken into consideration by the organization while establishing its environmental performance goals; to learn how the different kinds of environmental indicators are handled by organizations on daily basis, considering the existence of interferences on the decision making process, whether or not the interested parties are integrated, and if there is an periodical evaluation of environmental performance and how it is handled. One also expects to identify the opportunities for improvement regarding the organization that is object of study.
Resumo:
O NAVSTAR/GPS (NAVigation System with Timing And Ranging/Global Po- sitioning System), mais conhecido por GPS, _e um sistema de navegacão baseado em sat_elites desenvolvido pelo departamento de defesa norte-americano em meados de 1970. Criado inicialmente para fins militares, o GPS foi adaptado para o uso civil. Para fazer a localização, o receptor precisa fazer a aquisição de sinais dos satélites visíveis. Essa etapa é de extrema importância, pois é responsável pela detecção dos satélites visíveis, calculando suas respectivas frequências e fases iniciais. Esse processo pode demandar bastante tempo de processamento e precisa ser implementado de forma eficiente. Várias técnicas são utilizadas atualmente, mas a maioria delas colocam em conflito questões de projeto tais como, complexidade computacional, tempo de aquisição e recursos computacionais. Objetivando equilibrar essas questões, foi desenvolvido um método que reduz a complexidade do processo de aquisição utilizando algumas estratégias, a saber, redução do efeito doppler, amostras e tamanho do sinal utilizados, além do paralelismo. Essa estratégia é dividida em dois passos, um grosseiro em todo o espaço de busca e um fino apenas na região identificada previamente pela primeira etapa. Devido a busca grosseira, o limiar do algoritmo convencional não era mais aceitável. Nesse sentido, um novo limiar foi estabelecido baseado na variância dos picos de correlação. Inicialmente, é feita uma busca com pouca precisão comparando a variância dos cinco maiores picos de correlação encontrados. Caso a variância ultrapasse um certo limiar, a região de maior pico torna-se candidata à detecção. Por fim, essa região passa por um refinamento para se ter a certeza de detecção. Os resultados mostram que houve uma redução significativa na complexidade e no tempo de execução, sem que tenha sido necessário utilizar algoritmos muito complexos.
Resumo:
Although efficient from a technical point of view, mortar layers that make up the traditional masonry coating (slurry mortar, plaster and plaster) have to be in contradiction with the new construction technologies and more efficient methods of consumption and work rationalization. From an environmental point of view, the recovery of waste into new composites for the building has been a growing strand of studies in the scientific community, may prove to be a cost-effective solution in some cases. Thus, this research proposes the development of a mortar Decorative Coating Monolayer (RDM), for use in facades, produced on site, incorporating tempered glass waste (RVT) in the cement matrix, as a partial substitute for aggregate. Therefore, we adopted the binder respect / aggregate of 1: 6 (by volume), consistency index 250mm ± 20, sand substitution levels of glass waste 20%, 50% and 80% and relative water / cement varied in many traits. Two additives were used, a polymer, styrene-butadiene-based, and other chemical, besides mineral and silica fume inorganic pigment in colors red, yellow and blue. Mechanical tests were carried out on fresh pasta and hardened, as well as for the applied coating on masonry, so as to demonstrate the feasibility of the material. In addition, it verified the adequacy of the RDM built environment by means of thermal tests. The results demonstrated the feasibility of the proposed RDM with significantly higher values when compared to norms, especially the dash-added replacement content of 20% and addition of pigment in red. Therefore, the study shows the scientific community as an incentive to the use of technological innovations in construction, increasing the range of alternatives available for housing production, with the proposition of a material that achieves the desired functionality and obtain environmental gain, and may be adopted on construction sites as an alternative industrialized mortars.
Medidas de concentração de radônio proveniente de argamassas de cimento portland, gesso e fosfogesso
Resumo:
Portland cement being very common construction material has in its composition the natural gypsum. To decrease the costs of manufacturing, the cement industry is substituting the gypsum in its composition by small quantities of phosphogypsum, which is the residue generated by the production of fertilizers and consists essentially of calcium dihydrate and some impurities, such as fluoride, metals in general, and radionuclides. Currently, tons of phosphogypsum are stored in the open air near the fertilizer industries, causing contamination of the environment. The 226 Ra present in these materials, when undergoes radioactive decay, produces the 222Rn gas. This radioactive gas, when inhaled together with its decay products deposited in the lungs, produces the exposure to radiation and can be a potential cause of lung cancer. Thus, the objective of this study was to measure the concentration levels of 222Rn from cylindrical samples of Portland cement, gypsum and phosphogypsum mortar from the state of Paraná, as well as characterizer the material and estimate the radon concentration in an environment of hypothetical dwelling with walls covered by such materials. Experimental setup of 222Rn activity measurements was based on AlphaGUARD detector (Saphymo GmbH). The qualitative and quantitative analysis was performed by gamma spectrometry and EDXRF with Au and Ag targets tubes (AMPTEK), and Mo target (ARTAX) and mechanical testing with x- ray equipment (Gilardoni) and the mechanical press (EMIC). Obtained average values of radon activity from studied materials in the air of containers were of 854 ± 23 Bq/m3, 60,0 ± 7,2 Bq/m3 e 52,9 ± 5,4 Bq/m3 for Portland cement, gypsum and phosphogypsum mortar, respectively. These results extrapolated into the volume of hypothetical dwelling of 36 m3 with the walls covered by such materials were of 3366 ± 91 Bq/m3, 237 ± 28 Bq/m3 e 208 ± 21 Bq/m3for Portland cement, gypsum and phosphogypsum mortar, respectively. Considering the limit of 300 Bq/m3 established by the ICRP, it could be concluded that the use of Portland cement plaster in dwellings is not secure and requires some specific mitigation procedure. Using the results of gamma spectrometry there were calculated the values of radium equivalent activity concentrations (Raeq) for Portland cement, gypsum and phosphogypsum mortar, which were obtained equal to 78,2 ± 0,9 Bq/kg; 58,2 ± 0,9 Bq/kg e 68,2 ± 0,9 Bq/kg, respectively. All values of radium equivalent activity concentrations for studied samples are below the maximum level of 370 Bq/kg. The qualitative and quantitative analysis of EDXRF spectra obtained with studied mortar samples allowed to evaluate quantitate and the elements that constitute the material such as Ca, S, Fe, and others.
Resumo:
Lightweight concrete has been the subject of several studies towards the development of new building materials. Emphasis has been given on the particle size effect and nature of aggregates used as raw materials. The present study includes an analysis of the materials that make this kind of concrete, analyzes of mechanical properties such as compressive and tensile strength, in addition to assessments of the interface concrete aggregate/matrix interface, porosity and absorption profile of chloride ions in lightweight concrete based on expanded clay. The experiments were carried out by molding cylindrical samples 100 mm in diameter and 200 mm in height. The dosage experiments were performed without additives or with the addition of minerals: (T1) 1: 2.01: 1.10: 0.78 (T2) 1: 2.00: 1.32 : 0.62 - (T3) 1 :1.93 :1.54: 0.47 (cement : sand : expanded clay 0500 : expanded clay 1506).The water to cement ratio was set to 0.43. Expanded clay minerals with different average particle sizes were used, i.e., 9.5 mm/0500 and 19 mm/1506. The larger aggregate was coated by a glassy layer, yielding lower water absorption characteristics to the concrete. The results showed that the use of light expanded clay aggregates is a technically interesting solution to the production of lightweight concrete for construction applications