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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

Estudo da adi??o de finos de rocha na fabrica??o de blocos e tijolos de veda??o do extremo sul da Bahia

Reis, Edmilson Pedreira dos 28 June 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-22T20:18:42Z No. of bitstreams: 1 EdmilsonPedreiraDosReis_TESE.pdf: 5834887 bytes, checksum: a922e6dfba67996da893a14164e1ce7d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-22T23:56:34Z (GMT) No. of bitstreams: 1 EdmilsonPedreiraDosReis_TESE.pdf: 5834887 bytes, checksum: a922e6dfba67996da893a14164e1ce7d (MD5) / Made available in DSpace on 2017-11-22T23:56:34Z (GMT). No. of bitstreams: 1 EdmilsonPedreiraDosReis_TESE.pdf: 5834887 bytes, checksum: a922e6dfba67996da893a14164e1ce7d (MD5) Previous issue date: 2016-06-28 / O ?p? de pedra? ? um res?duo resultante do beneficiamento de rochas para obten??o de britas utilizadas na constru??o civil, tendo estas o seu uso mais comum em concretos. A sua gera??o ? na ordem de 10% a 15% do volume total de pedra beneficiada e, normalmente, s?o depositadas na ?rea da empresa de minera??o. O objetivo desta pesquisa foi desenvolver blocos e tijolos cer?micos, com mat?riasprimas provenientes da regi?o de Eun?polis, no extremo sul da Bahia, com adi??o deste res?duo na argila de queima vermelha. Com isso, pretende-se dar destino adequado ao res?duo e, ao mesmo tempo, preservar as jazidas de argila da regi?o, reduzindo o impacto ambiental causado por sua explora??o. As massas cer?micas foram formuladas com a t?cnica de planejamento de misturas, utilizando, para isso, o software Statistic. As porcentagens do res?duo na massa foram de 0, 15 e 30%, em massa, definidas pelo software em fun??o do limite m?ximo de 30% de res?duo que foi utilizada na massa cer?mica. Foram confeccionados corpos de provas nas dimens?es de 60x20x5 mm3 em matriz met?lica, e prensados uniaxialmente com uma press?o de 25 MPa. A queima ocorreu nas temperaturas de 825?C, 925?C e 1025?C, com taxa de aquecimento de 1?C/min, 8?C/min e 15?C/min, e patamar de 180 minutos na temperatura m?xima. A caracteriza??o das mat?rias-primas e das massas formuladas foi realizada atrav?s de ensaios de granulometria, limites de Atterberg, fluoresc?ncia de raios X (FRX), difra??o de raios X (DRX), microscopia eletr?nica de varredura (MEV), microscopia ?tica (MO), an?lise termogravim?trica (TG) e calorimetria explorat?ria diferencial (DSC). As propriedades f?sicas determinadas foram a absor??o de ?gua, retra??o linear, porosidade, resist?ncia ? flex?o e massa espec?fica aparente. Foi analisado, tamb?m, o comportamento da massa cer?mica, no que diz respeito ? extrus?o dos blocos cer?micos em extrusora de laborat?rio, determinando a sua resist?ncia ? compress?o (Rc) e absor??o de ?gua (AA). A efic?cia do planejamento de misturas foi confirmada, realizando os mesmos ensaios mec?nicos e f?sicos em uma nova formula??o feita com percentual diferente das utilizadas para obten??o do modelo de regress?o, mas ainda, dentro da regi?o de interesse. A an?lise dos resultados permitiu demonstrar a viabilidade da incorpora??o do res?duo em at? 30% nas argilas, para fabrica??o de blocos cer?micos e tijolos maci?os utilizados em alvenaria de veda??o. / Stone dust is a residue resulting from the processing of rocks for obtaining gravel used in civil construction, most commonly in concrete. It is generated in the order of 10% to 15% of the total volume of the stone employed and is typically deposited throughout and around the area of the mining company. The objective of this study was to develop and ceramic blocks and bricks utilizing raw materials readily available in region of Eun?polis, extreme south of Bahia, with the addition of this residue to the red clay. Consequently, it aims to provide a suitable end-use for the residue, at the same time preserving deposits of clay in the region by reducing the environmental impact caused by their exploitation. The ceramic masses were formulated following a mixture-planning technique through the use of the Statistic software. The total percentages of residue used in the mass were of between 15% and 30%, as defined by the software on the stipulation of a 30% ceiling on the residue used in the mass. In a metal matrix, 60x20x5 mm3 test samples were created and then pressed uni-axially at a pressure of 25 MPa. The firing was performed at temperatures of 825?C, 925?c and 1025?C, with concordant heating rates of 1?C/min, 8?C/min and 15?C/min and an established time limit of 180 minutes at the maximum temperature. Characteristics of the raw materials and resultant masses were measured through testing of granulometry, Atterberg limits, X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), optical microscopy (OM), thermos-gravimetric analysis (TGA) and exploratory differential scanning calorimetry (DSC). The physical properties measured were determined water absorption, linear retraction, porosity, resistance to flexion and apparent specific mass. Additionally, the behavior of ceramic mass in regards to extrusion of the ceramic blocks using a laboratory extruder was analyzed, determining its resistance to compression (Rc) and water absorption (AA). Effectiveness of the mixture formulation was confirmed by performing the same physical and mechanical testing on a new formulation with different percentages than those used for obtaining the regression model, though still within the targeted range. Analysis of the results demonstrated the viability of incorporating the residue in masses, in quantities of up to 30%, for the manufacture of solid ceramic blocks and bricks used in masonry.
2

Low cement structural lightweight concrete with optimized multiple waste mix design / Concreto leve estrutural de baixo consumo de cimento com misturas otimizadas de res?duos

Sampaio, Zodinio Laurisa Monteiro 25 April 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-22T20:18:43Z No. of bitstreams: 1 ZodinioLaurisaMonteiroSampaio_TESE.pdf: 4245538 bytes, checksum: 687e089323cb706bdb8dc70fe1aa7593 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-23T00:28:27Z (GMT) No. of bitstreams: 1 ZodinioLaurisaMonteiroSampaio_TESE.pdf: 4245538 bytes, checksum: 687e089323cb706bdb8dc70fe1aa7593 (MD5) / Made available in DSpace on 2017-11-23T00:28:27Z (GMT). No. of bitstreams: 1 ZodinioLaurisaMonteiroSampaio_TESE.pdf: 4245538 bytes, checksum: 687e089323cb706bdb8dc70fe1aa7593 (MD5) Previous issue date: 2017-04-25 / The high-energy demand involved in the construction industry and the increasing consumption of concrete made this material an ideal option for the recycling of by-products from various industries such as: porcelain polishing residue (PPR); tire rubber residue (TRR) and limestone residue (LSR). These residues often lack a treatment that contributes to the degradation of the environment. In this sense, the use of by-products that increases the volume of the concrete without damaging significantly its properties, can be a viable option in the production of low-cost and sustainable low-weight concrete (LWC). The main objective of this work was to analyze the mechanical and thermal behavior of structural lightweight concrete (SLWC) with low cement consumption, produced with expanded clay (EC) in replacement of the aggregate and with the addition of PPR, TRR and LSR to replace the small aggregate. For this purpose, a 2? factorial design was used for the choice of SLWC with the best performance in terms of consistency, mechanical properties and density. Subsequently, reductions of 10, 20 and 30% of cement were performed on SLWC that presented better combination of properties and waste consumption and were characterized by mechanical tests. The best SLWC mix resulting from the combination of mechanical properties and cement consumption was characterized by permeability, flexural strength, TG/DTA, XRF, SEM, thermal capacity, thermal conductivity and thermal diffusivity. The results showed that residues contents around 21% presented better combination of properties. By maintaining the amount of residue at optimum levels it was possible to produce a SLWC with good rheological, mechanical and thermal properties with minimum cement consumption. / A alta demanda energ?tica envolvida na ind?stria da constru??o civil e o crescente consumo do concreto, fez com que o concreto se tornasse a op??o ideal para a reciclagem de subprodutos de v?rias industrias tais como: res?duo de polimento de porcelanato PPR; res?duo de borracha de pneu (TRR) e res?duo de pedra calc?ria (LSR). Esses res?duos frequentemente carecem de um tratamento adequando o que acaba contribuindo para a degrada??o do meio ambiente. Nesse sentido, o uso de subprodutos que ir?o aumentar o volume do concreto sem prejudicar muito as propriedades, pode ser uma op??o bastante vi?vel na produ??o de Concretos leves (CL) de baixo custo e sustent?veis. O objetivo geral desse trabalho foi analisar o comportamento mec?nico e t?rmico de concretos leves estruturais (CLE) de baixo teor de cimento produzidos com argila expandida (AE) em substitui??o ao agregado gra?do e com adi??o de PPR, TRR e LSR em substitui??o a parte do agregado mi?do. Para tal foi usado inicialmente um planejamento fatorial 2? para a escolha dos CLE com melhor desempenho em termos de consist?ncia, propriedades mec?nicas e massa espec?fica real. Posteriormente foram realizadas redu??es de 10, 20 e 30% de cimento nos CLE que apresentaram melhores desempenhos e caracterizados atrav?s de ensaios mec?nicos. O melhor tra?o resultante da combina??o de propriedades mec?nicas com o consumo de cimento foi caracterizado mediante ensaios de: permeabilidade; resist?ncia ? flex?o; TG/DTA; FRX; MEV; capacidade t?rmica; condutividade t?rmica e difusividade t?rmica. Por fim. Os resultados mostraram que teores de res?duos em torno de 21% apresentaram melhor combina??o de propriedades. Mantendo os teores de res?duos em n?veis ?timos foi poss?vel produzir um CLE com boas propriedades reol?gicas, mec?nicas e t?rmicas com um consumo m?nimo de cimento.

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