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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Incorpora??o do res?duo oriundo do beneficiamento de caulim em concreto asf?ltico / Incorporation of the residue originating from the improvement of kaolin in asphalt concrete

Costa, Cibele Gouveia 10 November 2006 (has links)
Made available in DSpace on 2014-12-17T15:03:18Z (GMT). No. of bitstreams: 1 CibeleGC.pdf: 1402838 bytes, checksum: db637069ba867fa96c00ae8cf6ff383c (MD5) Previous issue date: 2006-11-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The municipal district of Equador-RN is located in an area of great amounts of ores, being your main economical activity the extraction and the kaolin improvement. The main originating from environmental problem that activity is the amount of generated residue, about 70% of the extracted kaolin. The residues are simply piled up in lands of the improvement companies, occupying like this a large area and causing impact in the existent flora. When dry, the residues transform powdered and for the action of the wind, they disperse, polluting the air. Being like this, the present work has as objective evaluates the incorporation of the great residue, originating from of the kaolin improvement, in partial substitution of all the employed aggregates in a conventional mixture of asphalt concrete, which was used in the paving of BR101/RN061 - passage between Ponta Negra and Ares. That evaluation was accomplished in three stages. The first refers to the evaluation of the physical, thermal and mineralogical characteristics of the residue with the intention of to classify it and to define your application as aggregate (small and great). The second refers to the physical characterization of the aggregates and of the asphalt material used in the conventional mixture. And the third, to the evaluation of the mixtures containing residue, which were elaborated starting from the conventional mixture with the gradual incorporation of the residue, from 5 to 40%, in substitution to the part of the conventional aggregates, in way to obtain similar particle size curves the one of the conventional mixture. That evaluation was accomplished through the comparison between the volumetric composition, the mechanical behavior and the susceptibility to the humidity of the mixtures containing residue with the one of the conventional mixture, and with the one of the DNIT specifications. The results show that the great residue originating from of the kaolin improvement has grains of the most varied size, being like this, it can substitute part of all the conventional aggregates and of the filler in an asphalt mixture. Besides, your mineralogical composition presented the same present minerals in the composition of conventional aggregates used in paving. The results evaluation of the volumetric composition of the mixtures containing residue indicates that it can use up to 30% of residue in substitution to the conventional aggregates. The evaluation of the mechanical behavior of those mixtures indicates that the residue increment in the studied mixtures caused an increase of the stability and a reduction of the resistance to the traction. The values obtained in the resistance to the traction meet below the minimum value specified by DNIT, but close to the value obtained in the conventional mixture. When taking in consideration the susceptibility of the same ones to the humidity, the results indicate that she can use up to 25% of residue / O munic?pio de Equador-RN est? localizado numa regi?o de grandes quantidades de min?rios, sendo sua principal atividade econ?mica a extra??o e o beneficiamento de caulim. O principal problema ambiental proveniente dessa atividade ? a quantidade de res?duo gerado, cerca de 70% do caulim extra?do. Os res?duos s?o simplesmente amontoados em terrenos das empresas de beneficiamento, ocupando assim uma grande ?rea e causando impacto na flora existente. Quando secos, os res?duos transformam-se em p? e pela a??o do vento, se espalham, poluindo o ar. Sendo assim, o presente trabalho tem como objetivo avaliar a incorpora??o do res?duo grosso, oriundo do beneficiamento de caulim, em substitui??o parcial de todos os agregados empregados em uma mistura convencional de concreto asf?ltico, a qual foi utilizada na pavimenta??o da BR101/RN061 trecho entre Ponta Negra e Ares. Essa avalia??o foi realizada em tr?s etapas. A primeira refere-se ? avalia??o das caracter?sticas f?sicas, t?rmicas e mineral?gicas do res?duo com o intuito de classific?-lo e definir sua aplica??o como agregado (mi?do e gra?do). A segunda refere-se ? caracteriza??o f?sica dos agregados e do material asf?ltico utilizados na mistura convencional. E a terceira ? avalia??o das misturas contendo res?duo, as quais foram elaboradas a partir da mistura convencional com a incorpora??o gradativa do res?duo, de 5 a 40%, em substitui??o ? parte dos agregados convencionais, de forma a obter curvas granulom?tricas similares a da mistura convencional. Essa avalia??o foi realizada atrav?s da compara??o entre a composi??o volum?trica, o comportamento mec?nico e a suscetibilidade ? umidade das misturas contendo res?duo com os da mistura convencional, e com os das especifica??es exigidas pelo DNIT. Os resultados mostram que o res?duo grosso oriundo do beneficiamento de caulim possui gr?os dos mais variados di?metros, sendo assim, pode substituir parte de todos os agregados convencionais e do filler em uma mistura asf?ltica. Al?m disso, a sua composi??o mineral?gica apresentou os mesmos minerais presentes na composi??o de agregados convencionais utilizados em pavimenta??o. Os resultados da avalia??o da composi??o volum?trica das misturas contendo res?duo indicam que se pode empregar at? 30% de res?duo em substitui??o aos agregados convencionais. A avalia??o do comportamento mec?nico dessas misturas indicam que o incremento de res?duo nas misturas estudadas ocasionou um aumento da estabilidade e uma redu??o da resist?ncia ? tra??o. Os valores obtidos na resist?ncia ? tra??o se encontram abaixo do valor m?nimo especificado pelo DNIT, mas pr?ximos ao valor obtido na mistura convencional. Ao levar em considera??o a suscetibilidade das mesmas ? umidade, os resultados indicam que se pode empregar at? 25% de res?duo
2

Estudo de viabilidade t?cnica do uso de res?duos oriundos do beneficiamento de scheelita na composi??o de concretos asf?lticos / Technical feasibility study of using waste from scheelite processing in composition of asphaltic

Costa Filho, Francisco das Chagas da 03 February 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T23:06:42Z No. of bitstreams: 1 FranciscoDasChagasDaCostaFilho_DISSERT.pdf: 6168357 bytes, checksum: c578fb868ea385c90fbc6817fbe806b9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-24T21:28:11Z (GMT) No. of bitstreams: 1 FranciscoDasChagasDaCostaFilho_DISSERT.pdf: 6168357 bytes, checksum: c578fb868ea385c90fbc6817fbe806b9 (MD5) / Made available in DSpace on 2017-03-24T21:28:11Z (GMT). No. of bitstreams: 1 FranciscoDasChagasDaCostaFilho_DISSERT.pdf: 6168357 bytes, checksum: c578fb868ea385c90fbc6817fbe806b9 (MD5) Previous issue date: 2017-02-03 / A produ??o mineral brasileira ? uma atividade de suma import?ncia para a economia do pa?s, visto que al?m de contribuir para o produto interno bruto - PIB, ? respons?vel pela gera??o de muitos empregos diretos e indiretos. Neste cen?rio, a minera??o Tomaz Salustino S/A (Mina Breju?) ? uma grande representante nordestina deste setor. Dados de 2012 demonstram que a produ??o da Mina Breju? era em torno de 20 toneladas mensais (MACHADO 2012), representando mais de 300 empregos gerados, al?m do desenvolvimento do munic?pio de Currais Novos, onde a empresa est? situada. Entretanto, devido ao beneficiamento do min?rio (scheelita), desde 1943, foram geradas toneladas de res?duos, e, atualmente, estima-se que no entorno da minera??o existe cerca de 7 milh?es de toneladas (4,5 milh?es de fra??o grossa e 2,5 milh?es de fra??o fina), dispostos em pilhas e bacias de res?duos, gerando diversos impactos ambientais, como a modifica??o da paisagem local. Em vista deste grande estoque de res?duo, aliado a necessidade de extra??o de mat?ria prima natural para compor as camadas usuais de um pavimento, o presente estudo avaliou a viabilidade t?cnica dos res?duos provenientes da Mina Breju? na composi??o de concretos asf?lticos, em substitui??o ao agregado mi?do natural, pela fra??o grossa do res?duo, e, do f?ler convencional, pela fra??o fina do res?duo. Para isto, realizaram-se ensaios de caracteriza??o f?sica, qu?mica e mineral?gica das fra??es do res?duo e dos agregados naturais utilizados na pesquisa, al?m de dosagens Marshall em composi??es de concretos asf?lticos para analisar os par?metros volum?tricos e a estabilidade dos materiais quanto a utiliza??o em obras vi?rias. A partir do programa experimental proposto, pode-se verificar que a fra??o grossa do res?duo do beneficiamento da scheelita apresentou um potencial elevado para ser utilizado in natura como agregado mi?do, pois os corpos de prova analisados demonstraram bom desempenho com rela??o aos par?metros volum?tricos e a estabilidade Marshall. A fra??o fina tamb?m se mostrou vi?vel para ser utilizada como f?ler artificial, por?m, para tal aplica??o, se faz necess?rio processos de melhoramento de qualidade para que a fra??o do res?duo se enquadre como material de enchimento de misturas asf?lticas, visto que in natura, a mesma n?o apresentou os 65% de material passante na peneira de 0,075 mm requisitado pela norma DNER - EM 367/97 (DNER, 1997a). / The Brazilian mineral production is an extremely important activity for the country's economy, since in addition to contributing to gross national product - PIB, it is responsible for the generation of many direct and indirect jobs. Therefore, the Tomaz Salustino Corporation Mining (Breju? Mine) is a important northeastern representative of this sector. Data for 2012 show that the production of the Breju? Mine was around 20 tons per month (MACHADO 2012), representing more than 300 jobs generated, in addition to the development of the municipality of Currais Novos. However, due to the ore (scheelite) processing, since 1943, tons of waste have been generated, and it is currently estimated around 7 million tons (4.5 million thick fractions and 2.5 million fine fractions), disposed in piles and waste basins, generating several environmental impacts, such as the modification of the local landscape. Due of this large stock of waste, jointly with the need for extraction of natural raw material to compose the usual layers of a pavement, the present study evaluated the technical feasibility of the residues from the Breju? Mine in the composition of asphaltic concretes, replacing the natural small aggregate by the thick fractions of the residue, and the conventional filler by the fine fractions of the residue. For this, chemical and mineralogical characterization of fractions of the residue and of the natural aggregates used in the research, besides Marshall dosages in compositions of asphaltic concretes was carried out to analyze the volumetric parameters and the stability of the materials as for the use in road works. From the proposed experimental program, it can be verified that the thick fractions of the scheelite processing residue presented a high potential to be used in natura as a small aggregate, because the analyzed specimens showed good performance in relation to the volumetric parameters and the Marshall stability. The fine fraction has also proved feasible to be used as an artificial filler, however, for this application, it is necessary to improve the quality for that the fraction of the residue fits as asphalt mixtures filling material since, in natura, it did not present the 65% passing material in the 0.075 mm sieve required by DNER - EM 367/97 (DNER, 1997a).

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