Το πρόγραμμα συντήρησης του μοναστηριακού συγκροτήματος του Αγίου Λωτ περιελάμβανε in situ επεμβάσεις συντήρησης, σωστική αποκόλληση και επανατοποθέτηση ενός από τα έξι ψηφιδωτά δάπεδα που βρίσκονταν στην Βασιλική και την ανασκαφή ενός ψηφιδωτού που είχε καταρρεύσει και κατακερματιστεί σε εκατοντάδες θραύσματα στην κλιτύ του λόφου, όπου βρίσκεται η Μονή. Η αποκόλληση του πρώτου ψηφιδωτού δαπέδου και η επακόλουθη ανακάλυψη ενός πρωιμότερου ψηφιδωτού δαπέδου κάτω από αυτό, καθώς και η εύρεση ενός ακόμα σε θραύσματα μας έδωσε την ευκαιρία να παρατηρήσουμε και να καταγράψουμε επιμελώς τις τεχνικές που χρησιμοποιήθηκαν στην κατασκευή των ψηφιδωτών. Ο χαρακτηρισμός επιλεγμένων δειγμάτων κονιαμάτων μας επέτρεψε να προσδιορίσουμε τη σύστασή τους και να ταυτοποιήσουμε το είδος των αδρανών και των προσμίξεων που εμπεριέχει. Οι τεχνικές που χρησιμοποιήθηκαν για την ανάλυση των κονιαμάτων είναι οι: η Περιθλασιμετρία κόνεως ακτίνων-Χ (XRD), η Ηλεκτρονική Μικροσκοπία Σάρωσης (SEM- EDS), η Φασματοσκοπία Απορρόφησης Υπερύθρου (FTIR) και η Οπτική Μικροσκοπία (ΟΜ). Επιπλέον, η πετρογραφική ανάλυση των ψηφίδων, που έγιναν από συνεργάτες του έργου, μας έδωσαν πληροφορίες σχετικά με την προέλευση των πρώτων υλών που χρησιμοποιήθηκαν. Μετά από αναλύσεις και λεπτομερή παρατήρηση, λάβαμε πληροφορίες σχετικά με τις πρώτες ύλες, την προετοιμασία των κονιαμάτων, την στρωματογραφία του ψηφιδωτού δαπέδου, την μέθοδο εκτέλεσης των εργασιών κατασκευής, αλλά και τον τρόπο επεξεργασίας της επιφάνειας. Οι διαφορές που παρατηρούνται στην στρωματογραφία και τη σύσταση των κονιαμάτων, όπως και στις ψηφίδες σε ψηφιδωτά που δημιουργήθηκαν σε διαφορετική χρονική περίοδο συμβάλλουν στην αρχαιολογική μελέτη και κυρίως στην κατανόηση της αρχιτεκτονικής ενότητας και μετατροπών που υπέστη κατά την διάρκεια της χρήσης του χώρου. / The conservation project at the monastic complex of Saint Lot involved the rescue lifting of one of the six mosaics which paved the basilica as well as the excavation of a second one that was found in hundreds of fragments fallen on the slope. The lifting of the first mosaic and the consequent discovery of fragments of an earlier mosaic floor underneath it, as well as the fragmentary state of the second mosaic gave us the opportunity to observe and record thoroughly the techniques employed in the construction of these mosaics. Characterization of selected mortar samples allowed the determination of their composition, identification of the aggregate and its additives. X-Ray Diffraction, Fourier transform infrared spectroscopy, Optical Microscopy and Scanning Electron Microscopy with EDS were the main techniques employed. Mineralogical analyses of tesserae samples, that was employed from other partners of the project, provided information about the provenance of the raw materials that were used. Through detailed observation and analysis, significant information on the raw material selection, preparation of mortars, bedding stratigraphy, method of execution, as well as aspects of tesserae cutting and surface finishing techniques were documented. The variation in the bedding stratigraphy, the composition of the mortars as well as the petrography of the tesserae between mosaics that were executed in different periods contribute in the study of the archaeological context and especially in understanding the succession of the renovation and modification phases of the building.

<p>This dissertation addresses interface problems simulated with the finite element method (FEM) with mesh adaptivity. More specifically, we concentrate on the strategies that adaptively modify the mesh and the associated data transfer issues. </p><p>In finite element simulations there often arises the need to change the mesh and continue the simulation on a new mesh. Analysts encounter such an issue when they adaptively refine the mesh to reduce the computational cost, smooth distorted elements to improve system conditioning, or introduce new surfaces and change the domain in simulations of fracture problems. In such circumstances, the transfer of data from the old mesh to the new one is of crucial importance, especially for nonlinear problems. We are concerned in this work with contact problems with adaptive re-meshing and fracture problems modeled with the eXtended finite element method (X-FEM). For the former ones, the transfer of surface data is built upon the technique of parallel transport, and the error of such a transfer strategy is investigated through classic benchmark tests. A transfer scheme based on a least squares problem is also proposed to transfer the bulk data when nearly incompressible hyperelastic materials are employed. For the latter type of problems, we facilitate the transfer of internal variables by making partial elements utilize the same quadrature points from the uncut parent elements and meanwhile adjusting the quadrature weights via the solution of moment fitting equations. The proposed scheme helps avoid the complicated remapping procedure of internal variables between two different sets of quadrature points. A number of numerical examples are presented to demonstrate the robustness and accuracy of our proposed approaches.</p><p>Another renowned technique to simulate fracture problems is based upon the phase-field formulation, where a set of coupled mechanics and phase-field equations are solved via FEM without modeling crack geometries. However, losing the ability to model distinct surfaces in the phase-field formulation has drawbacks, such as difficulties simulating contact on crack surfaces and poorly-conditioned stiffness matrices. On the other hand, using the pure X-FEM in fracture simulations mandates the calculation of the direction and increment of crack surfaces at each step, introducing intricacies of tracing crack evolution. Thus, we propose combining phase-field and X-FEM approaches to utilize their individual benefits based on a novel medial-axis algorithm. Consequently, we can still capture complex crack geometries while having crack surfaces explicitly modeled by modifying the mesh with the X-FEM.</p> / Dissertation

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-12T16:05:55Z No. of bitstreams: 1 GUILHERME COSTA DE OLIVEIRA - TESE PPGEQ 2016.pdf: 2637788 bytes, checksum: 666ee4637bd3109b74c369b5faba3164 (MD5) / Made available in DSpace on 2018-03-12T16:05:55Z (GMT). No. of bitstreams: 1 GUILHERME COSTA DE OLIVEIRA - TESE PPGEQ 2016.pdf: 2637788 bytes, checksum: 666ee4637bd3109b74c369b5faba3164 (MD5) Previous issue date: 2016-08-31 / Capes / Dentre os diversos minerais extraídos, no Brasil, o caulim é um dos principais. Esse mineral de da família das caulinitas, apresenta uma grande versatilidade quanto ao seu uso. Porém, durante o processo de beneficiamento, altas quantidades do material extraído são rejeitadas, chegando a 70% do montante. Esse resíduo é disposto a céu aberto, causando transtorno às populações circunvizinhas e ao ecossistema da região. Esse trabalho objetivou utilizar o resíduo gerado nesse processo como matéria prima para o desenvolvimento de argamassas. O resíduo foi caracterizado, e utilizando a difratometria de raios X (DRX) verificou-se que é, basicamente, constituído de caulinita e mica. O resíduo foi testado quanto à sua pozolanicidade e verificouse que não apresentava potencial adequado para ser utilizado como substituinte parcial do cimento. Entretanto, suas características físicas indicaram que o resíduo de caulim apresentava propriedades para ser utilizado como agregado miúdo. Traços de argamassas colantes foram realizados substituindo o agregado miúdo natural, areia, pelo resíduo do caulim em proporções de 0 a 100 %. Essas argamassas foram testadas de acordo com as especificações contidas na norma ABNT NBR 14081. Os resultados indicaram que, à medida que se aumentou a quantidade de resíduo, a argamassa necessitou de uma maior quantidade de água para se obter a trabalhabilidade adequada. Com relação aos dados de resistências mecânicas, verificou-se um decaimento linear nos dados. Para o Tempo em Aberto (TA), observou-se uma redução de, aproximadamente, 90% na resistência mecânica do material; com relação às Resistências de Aderência à Tração (RAT), houve diminuição de 87% nas resistências mecânicas dos traços curados ao ar e, 81 %, nas argamassas curadas em meio aquoso. O traço que continha 25 % de seu agregado natural substituído por resíduo de caulim, apresentou valores dentro dos limites estabelecidos pela NBR 14081 e uma demanda de água próxima à das argamassas colantes industrializadas disponíveis no mercado. Dessa forma, o resíduo oriundo do processo de beneficiamento de caulim, apresentou-se como uma opção viável para a redução do uso de areia no desenvolvimento de argamassas colantes. Essa substituição foi favorável tanto para dar uma destinação ao resíduo, como também para a diminuição do uso de areia como agregado miúdo, uma vez que sua extração acarreta em diversos problemas ambientais. / Among various minerals extracted in Brazil, kaolin is one of most important. This mineral from the kaolinite family has great versatility as its use and during its beneficiation process, high amounts of the extracted material are rejected, reaching values as 70%. This residue is disposed on the environment with no treatment, causing inconvenience to surrounding communities and to the region ecosystem. This work aimed to use this residue as raw material for the construction industry, more specifically in the development of AC-I type adhesive mortars. The residue was characterized and by X-ray diffraction verified that it is basically constituted of kaolinite and mica. Based on Brazilian standards, the residue was tested for its pozzolanic and it was found that showed no suitable potential for using as a partial replacement for cement. However, its physical characteristics indicate that the kaolin residue had properties to be used as fine aggregate. Traces of adhesive mortars were made by replacing the fine natural aggregate, sand, by kaolin residue in proportions from 0 up to 100 %. The results indicated that, as it increased the amount of residue, the mortar required a larger amount of water to obtain adequate workability. Due to mechanical resistance data, there was a linear decay in. For the Open Time (TA), there was a reduction of approximately 90% in the mechanical strength of the material; and about to Resistance Adhesion Tensile (RAT), a reduction of 87 % in the mechanical strength of the admixtures air-cured and 81 % in the mortar cured in an aqueous medium. The admixtures that contained 25 % of its fine aggregate replaced by kaolin residue, showed values within the limits established by the NBR 14081 and a water demand close by the demand in industrialized adhesive mortars. Thus, the residue derived from kaolin beneficiation process, proved to be a viable option for reducing the use of sand in the development of adhesive mortars. This substitution is in favour both to give a destination to residue, also to reduce the use of sand as fine aggregate, since its extraction brings several environmental problems in.

Submitted by Kilvya Braga (kilvyabraga@hotmail.com) on 2017-12-01T15:29:59Z No. of bitstreams: 1 WANDENBERG BISMARK COLAÇO LIMA - TESE PPGCEMAT 2014.pdf: 5505255 bytes, checksum: a7cbe5978f9e1752dac3df3b7238fc4d (MD5) / Made available in DSpace on 2017-12-01T15:29:59Z (GMT). No. of bitstreams: 1 WANDENBERG BISMARK COLAÇO LIMA - TESE PPGCEMAT 2014.pdf: 5505255 bytes, checksum: a7cbe5978f9e1752dac3df3b7238fc4d (MD5) Previous issue date: 2014-08-30 / A indústria de lavra e beneficiamento de rochas ornamentais vem sendo citadas pelos ambientalistas como uma grande fonte de contaminação e poluição do meio ambiente, devido à enorme quantidade de resíduos gerados e que frequentemente são lançados diretamente nos ecossistemas. Por outro lado o emprego de argamassa expansiva para demolição e corte de rochas, vem sendo uma das mais procuradas tecnologias de corte utilizadas pelas indústrias extrativas, por suas inúmeras vantagens, ante outras tecnologias de corte utilizadas na lavra de rochas ornamentais. Assim o objetivo deste trabalho é estudar a viabilidade da incorporação na argamassa expansiva de demolição de resíduos dos processos de lavra e beneficiamento de rochas ornamentais além do caulim e gesso. Para tanto, foram realizados ensaios de caracterização de duas argamassas expansivas comerciais dos resíduos gerados nos processos de lavra e beneficiamento do granito do caulim e do gesso, avaliando-se a influência do percentual de incorporação e da granulometria dos mesmos no desempenho da argamassa expansiva. Concluindo-se que é possível a incorporação do caulim, do gesso e dos resíduos do beneficiamento de granitos e do pó da perfuração do granito, como carga nas argamassas expansiva, sem perdas consideráveis da pressão de expansão, para utilização em corte de rochas na lavra de rochas ornamentais. / The mining industry and processing of ornamental rocks has been cited by environmentalists as a major source of contamination and pollution of the environment, due to the enormous amount of waste generated and which often are released directly in the ecosystems. On the other hand the use of expansive grout for demolition and cutting of rocks, has been one of the most sought after cutting technologies used by extractive industries, for its numerous advantages, compared to other cutting technologies used in the ornamental rock mining. So the aim of this work is to study the feasibility of incorporation into the expansive mortar demolition waste from mining processes and processing of ornamental rocks beyond the kaolin and gypsum. For both tests were carried out to characterize two expansive commercial mortars of waste generated in the processes of mining and processing kaolin and granite plaster, by evaluating the influence of percentage of incorporation and the granulometry of the same expansive mortar performance. In conclusion-if that is possible the incorporation of kaolin, gypsum and waste from processing of Granites and granite drilling dust, as cargo on the expansive mortar, without considerable losses of the expansion pressure for use in cutting of rocks in the ornamental rock mining.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-12T21:09:02Z No. of bitstreams: 1 SUELLEN LISBOA DIAS BELTRÃO - TESE PPG-CEMat 2014..pdf: 5738943 bytes, checksum: 0bccb1785d07e57f9e0fe26f6e6d41cc (MD5) / Made available in DSpace on 2018-04-12T21:09:02Z (GMT). No. of bitstreams: 1 SUELLEN LISBOA DIAS BELTRÃO - TESE PPG-CEMat 2014..pdf: 5738943 bytes, checksum: 0bccb1785d07e57f9e0fe26f6e6d41cc (MD5) Previous issue date: 2014-08-27 / CNPq / O ambiente construído do futuro está sendo edificado no começo de uma nova era ecológica, a da reutilização. Nesse sentido, a utilização de resíduos como forma alternativa de substituição do cimento em argamassas pode vir a alcançar o patamar da sustentabilidade. A produção excessiva de resíduos de caulim tanto no estado da Paraíba como no interior do estado do Rio Grande do Norte vem sendo alvo de pesquisas. Os resíduos de caulim oriundos do processo de beneficiamento do caulim classificados como resíduo grosso e resíduo fino são descartados de forma indiscriminada no meio ambiente, causando grande impacto ambiental e prejudicando a população circunvizinha das pilhas de resíduos. Na tentativa de propor alternativas para a reutilização destes resíduos e produção de materiais inovadores para os mais variados setores da construção civil este trabalho apresenta como objetivo avaliar o comportamento mecânico e durabilidade de argamassas incorporadas com resíduo de caulim calcinado. A mistura utilizada foi composta por 50% de resíduo de caulim grosso + 50% de resíduo de caulim fino, foram incorporados em argamassas nas proporções em massa de 1:2:6 e 1:2:8 com teores de substituição do cimento de 0%, 5%, 10%, 15%, 20% e 30%. mento de 0%, 5%, 10%, 15%, 20% e 30%. As argamassas foram submetidas a curas distintas sendo estas, realizadas em ambiente interno e em ambiente externo, obedecendo as idades de 30, 60, 90, 180 e 360 dias e ainda submetidas aos ensaios de durabilidade acelerada por meio dos ciclos de molhagem e secagem. Para a incorporação deste resíduo nas argamassas foram realizadas a caracterização física, química e mineralógica do resíduo, assim como avaliação da temperatura de queima do resíduo para avaliação da reatividade da pozolana. A pozolana com melhor característica física foi determinada a uma temperatura de 800°C e a partir desta, deu-se prosseguimento a incorporação do resíduo de caulim calcinado sob forma de pozolana nas argamassas. Foram moldados corpos de prova cilíndricos de 50 mm x 100 mm. Os corpos de prova conforme o tipo de cura e idade foram avaliados mecanicamente através do ensaio de resistência a compressão simples. Amostras das argamassas foram pulverizadas em pistilo com almofariz de porcelana e peneiradas em peneira ABNT de n°200 após o ensaio de resistência a compressão para serem analisadas por meio das técnicas de difratometria de raios-X, análise térmica diferencial e gravimétrica Diante dos valores de resistência apresentados, as argamassas com substituição do cimento pelo resíduo de caulim calcinado, podem ser classificadas de acordo com a NBR 13281 (2001) como sendo do Tipo I com valores de resistência mecânica ≥ 0,1 e ≤ 4,0 (MPa) e Tipo II com ≥ 4,0 e ≤ 8,0 (MPa) para ambos os traços 1:2:6 e 1:2:8. / The built environment of the future is being built at the beginning of a new was ecological, that of re-use. In this sense, the use of waste as alternative way of replacing the cement in mortars can reach the level of sustainability. Excessive production of waste from kaolin in the state of Paraíba and in the interior of the state of Rio Grande has been under investigation. The kaolin residues from the processing of kaolin classified as waste are disposed of indiscriminately in the environment, causing great environmental impact and damaging the surrounding population of waste batteries. In an attempt to propose alternatives for reuse of this waste and the production of innovative materials for the most varied sectors of construction, this paper presents the objective of evaluating the mechanical behavior and durability of mortars incorporated with residue of calcined kaolin. The mixture used was composed of 50% kaolin residue + 50% fine kaolin residue, were incorporated into the mortars in 1: 2: 6 and 1: 2: 8 mass proportions with cement substitution of 0%, 5%, 10%, 15%, 20% and 30%. 0%, 5%, 10%, 15%, 20% and 30%. The mortars were submitted to different cures, these being carried out in an environment internal and external environment, obeying the ages of 30, 60, 90, 180 and 360 days and subjected to the tests of accelerated durability by means of the wetting and drying cycles. For the incorporation of this residue in mortars were carried out the physical, chemical and mineralogical characterization of the residue, as well as the evaluation of the burning temperature of the residue for evaluation of pozzolan reactivity. Pozolana with better characteristics physics was determined at a temperature of 800 ° C and from this it was the incorporation of the residue of calcined kaolin in the form of pozzolan in mortars. 50 cylindrical specimens were molded mm x 100 mm. The specimens according to the type of cure and age were evaluated mechanically by the compressive strength test simple. Samples of the mortars were sprayed in pistil with porcelain mortar and sieved in No. 200 ABNT sieve after the test compression strength to be analyzed by X-ray diffraction, differential and gravimetric thermal analysis values ​​presented, mortars with by the residue of calcined kaolin, can be classified according to the with NBR 13281 (2001) as Type I with resistance values mechanics ≥ 0.1 and ≤ 4.0 (MPa) and Type II with ≥ 4.0 and ≤ 8.0 (MPa) for both traces 1: 2: 6 and 1: 2: 8.

Made available in DSpace on 2014-12-17T14:06:53Z (GMT). No. of bitstreams: 1 CarlosRG.pdf: 3095179 bytes, checksum: 8f85422621006a6dd669bfabb5747ac9 (MD5) Previous issue date: 2009-08-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Although already to exist alternative technique and economically viable for destination of used tires, quantitative data on properties of constructive elements that use the rubber waste as aggregate still are restricted. In the present work, the waste proceeding from industry of retreading as material for manufacture of composite destined to the production of constructive elements was considered. Mechanical and thermal properties of mortar had been analyzed Portland cement with addition of waste without treatment, in the ratios of 10%, 20% and 30% in mass in relation to the mass of the cement, substituting the aggregate in the trace in mortar 1:5 mass cement and sand. The size of the used residue varied between 0,30mm and 4,8mm (passing in the bolter 4,8mm and being restrained in the one of 0,30mm), being it in the formats fibers and granular. The influences of the size and the percentage of residue added to the mortar (in substitution to the aggregate) in the thermal and mechanical properties had been considered. Assays of body-of-test in thestates had been become fullfilled cool (consistency index) and hardened (absorption of water for capillarity, strength the compression, traction and strength flexural). The work is centralized in the problem of the relation thermal performance /strength mechanics of used constructive systems in regions of low latitudes (Been of the Piau?), characterized for raised indices of solar radiation. / Apesar de j? existirem alternativas t?cnica e economicamente vi?veis para destina??o de pneum?ticos usados, dados quantitativos sobre propriedades de elementos construtivos que utilizam o res?duo de borracha como agregado ainda s?o restritos. No presente trabalho, considerou-se o res?duo proveniente de ind?stria de recauchutagem como material para fabrica??o de comp?sito destinado ? produ??o de elementos construtivos. Foram analisadas propriedades mec?nicas e t?rmicas de argamassa de cimento Portland com adi??o de res?duo sem tratamento, nas propor??es de 10%, 20% e 30% em massa em rela??o ? massa do cimento, substituindo o agregado no tra?o em massa 1:5 de argamassa cimento e areia. A granulometria do res?duo utilizado variou entre 0,30mm e 4,8mm (passando na peneira 4,8mm e ficando retido na de 0,30mm), sendo ele nos formatos fibroso e granular. Consideraram-se as influ?ncias da granulometria e do percentual de res?duo adicionado ? argamassa (em substitui??o ao agregado) nas propriedades t?rmicas e mec?nicas. Realizaram-se ensaios de corpos-deprova nos estados fresco (?ndice de consist?ncia) e endurecido (absor??o de ?gua por capilaridade, resist?ncia a compress?o e tra??o). O trabalho est? focado no problema da rela??o desempenho t?rmico /resist?ncia mec?nica de sistemas construtivos utilizados em regi?es de baixas latitudes (Estado do Piau?), caracterizadas por elevados ?ndices de radia??o solar.

Made available in DSpace on 2014-12-17T14:06:57Z (GMT). No. of bitstreams: 1 MariaLLOS.pdf: 1560615 bytes, checksum: 3380ba58cfe3314d3e58ae0d9f253793 (MD5) Previous issue date: 2008-08-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / 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 / A preocupa??o ambiental diz respeito, entre outras coisas, ao consumo excessivo ou ineficiente de recursos naturais n?o-renov?veis (LEITE, 2001). A ind?stria da constru??o civil ? considerada como a maior consumidora de mat?rias-primas naturais, contribuindo assim, de maneira relevante, para uma maior degrada??o do meio ambiente. A utiliza??o do res?duo de pedreira de rocha calc?ria (RPPC) e res?duo do polimento do porcelanato (RPP), em substitui??o parcial do cimento, pode ser um caminho alternativo para minimiza??o deste problema. Esta pesquisa teve como objetivo estudar as propriedades no estado fresco e endurecido das argamassas mistas produzidas com res?duos (RPPC e RPP), comparando o desempenho das mesmas com as argamassas de refer?ncia. Na produ??o dessas argamassas se utilizou o cimento Portland CP II F 32, cal hidratada CH I, areia de rio e ?gua da concession?ria local. Os res?duos utilizados foram caracterizados quanto a massa espec?fica, massa unit?ria, granulometria a laser,microscopia eletr?nica de varredura, difratometria de raios-X e fluoresc?ncia de raios-X. Os tra?os utilizados foram 1:1:6 e 1:0,5:4,5, ambos em volume, com a rela??o ?gua/cimento fixada, respectivamente, em 1,87 e 1,45. Foram produzidas 18 composi??es de argamassas, 16 utilizando RPPC e RPP e 02 composi??es convencionais que serviram de refer?ncia. Com as argamassas no estado fresco, foram realizados os ensaios de ?ndice de consist?ncia, reten??o de ?gua, densidade de massa e teor de ar incorporado. J? no estado endurecido, os ensaios realizados foram: densidade de massa aparente, m?dulo de elasticidade, resist?ncia ? tra??o na flex?o, resist?ncia ? compress?o e absor??o de ?gua por capilaridade. As argamassas foram analisadas por microscopia eletr?nica de varredura, espectroscopia de raios-X por energia dispersiva (EDS), difra??o de raios-X e fluoresc?ncia de raios-X. Al?m disso, foram classificadas quanto aos padr?es estabelecidos pela NBR 13281 (ABNT, 2005). Os resultados encontrados mostram que as argamassas formuladas com res?duos n?o sofreram altera??es significativas no que se refere ao ?ndice de consist?ncia, reten??o de ?gua, densidade de massa no estado fresco, teor de ar incorporado e densidade de massa aparente no estado endurecido. J? em rela??o ao m?dulo de elasticidade a presen?a dos res?duos na mistura ocasionou a diminui??o do mesmo, melhorando assim o desempenho da argamassa. Por?m, a resist?ncia ? tra??o na flex?o e ? resist?ncia ? compress?o, al?m da absor??o de ?gua por capilaridade, tiveram o seu desempenho comprometidos

Made available in DSpace on 2014-12-17T14:07:06Z (GMT). No. of bitstreams: 1 GelsoneideSG_DISSERT.pdf: 1818458 bytes, checksum: 7c978a688725815697ae8981fa5f2d16 (MD5) Previous issue date: 2013-02-18 / Generally, cellulose ethers improves mortar properties such as water retention, workability and setting time, along with adherence to the substrate. However, a major disadvantage of the addition of cellulose ethers in mortars is the delay in hydration of the cement. In this paper a cellulose phosphate (Cp) was synthesized water soluble and has been evaluated the effect of their incorporation into mortar based on Portland cement. Cellulose phosphate obtained was characterized by spectrophotometry Fourier transform infrared (FTIR), X-ray diffraction (XRD), elemental analysis and scanning electron microscopy (SEM). Mortar compositions were formulated with varying phosphorus content in cellulose and cellulose phosphate concentrations, when used in partial or total replacement of the commercial additive based hydroxyethyl methyl cellulose (HEMC). The mortars formulated with additives were prepared and characterized by: testing in the fresh state (consistency index, water retention, bulk density and air content incorporated) and in the hardened state (absorption by capillarity, density, flexural and compression strength). In mixtures the proportion of sand:cement of 1:5 (v / v) and factor a / c = 1.31 and water were held constant. Overall, the results showed that the celluloses phosphates employed in mortars added acted significantly when partially substituting the commercial additive. With regard to consistency index, water retention and bulk density in the fresh state and absorption by capillarity and bulk density apparent in the hardened state, showed no appreciable differences as compared to the commercial additive. The incorporated air content in the fresh state reduced markedly, but did not affect other properties. The mortars with cellulose phosphate, partially replacing the commercial additive showed an improvement of the properties of flexural strength and compressive strength / Geralmente, ?teres de celulose melhoram as propriedades de argamassas, tais como reten??o de ?gua, trabalhabilidade e o tempo de pega, juntamente com a ades?o ao substrato. No entanto, uma das principais desvantagens da adi??o dos ?teres de celulose nas argamassas ? o retardo na hidrata??o do cimento. Neste trabalho foi sintetizada uma celulose fosfatada (Cp) sol?vel em ?gua e foi avaliado o efeito da sua incorpora??o em argamassa ? base de cimento Portland. A celulose fosfatada obtida foi caracterizada por espectrofotometria de infravermelho por transformada de Fourier (FTIR), difra??o de raios-X (DRX), an?lise elementar, an?lise termogravim?trica (TGA) e microscopia eletr?nica de varredura (MEV). Argamassas com composi??es variando o teor de f?sforo relativamente ? celulose e as concentra??es de celulose fosfatada, quando utilizada em substitui??o parcial ou total do aditivo comercial a base de hidroxietil metil celulose (HEMC). As argamassas formuladas com os aditivos foram preparadas e caracterizadas por: ensaios no estado fresco (?ndice de consist?ncia, reten??o de ?gua, densidade e teor de ar incorporado) e no estado endurecido (absor??o por capilaridade, densidade, resist?ncia ? flex?o e compress?o). Nas misturas a propor??o de areia, cimento e ?gua foram mantidos constantes. De um modo geral, os resultados mostraram que as celuloses fosfatadas empregadas nas argamassas atuaram significativamente quando adicionados parcialmente em substitui??o ao aditivo comercial. No que se refere ao ?ndice de consist?ncia, reten??o de ?gua e densidade de massa no estado fresco e absor??o por capilaridade e densidade de massa aparente no estado endurecido, n?o demonstraram diferen?as apreci?veis comparativamente ao aditivo comercial. O teor de ar incorporado no estado fresco reduziu de forma marcante, mas n?o influenciou as demais propriedades. As argamassas com celulose fosfatada, substituindo parcialmente o aditivo comercial, mostraram uma melhora das propriedades de resist?ncia ? flex?o e de resist?ncia ? compress?o.

Made available in DSpace on 2014-12-17T14:48:13Z (GMT). No. of bitstreams: 1 FellipeCACM_DISSERT.pdf: 1867444 bytes, checksum: bdeaf70a3884fde7d06961686d3bb1db (MD5) Previous issue date: 2012-12-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / With the increase in cement consumption, it has quickly become one of the inputs most consumed by mankind over the last century. This has caused an increase in CO2 emissions, as cement production releases large quantities of this gas into the atmosphere. Adding this fact to the growing consciousness of environmental preservation, it has led to a search for alternatives to cement to complement its derivatives, in the form of waste materials like the ashes. This research aimed to analyze the properties of mortars in fresh and hardened state with partial replacement of Portland cement by residual algaroba wood ash (CRLA) potteries produced by the state of Rio Grande do Norte. The CRLA was collected and sieved, where part of it was ground and characterized in comparison with that just sifted, being characterized according to its chemical composition, grain size, fineness, density, bulk density and index of pozzolanic activity. It was found that the wood ash does not act as pozzolan, and grinding it has not changed its characteristics compared to those just sifted, not justifying its use. Two traces were adopted for this research: 1:3 (cement: fine sand) and 1:2:8 (cement: hydrated lime: medium sand); both in volume, using as materials the CRLA just sifted, CP II F-32 Portland cement, CH-I hydrated lime, river sand and water from the local utility. For each trace were adopted six percentages of partial replacement of cement for wood ash: 0% (control) 5%, 7%, 10%, 12% and 15%. In the fresh state, the mortars were tested towards their consistency index and mass density. In the hardened state, they were tested towards their tensile strength in bending, compressive strength and tensile adhesion strength, and its mass density in the hardened state. The mortar was also analyzed by scanning electron microscopy and X-ray diffraction. Furthermore, it was classified according to NBR 13281 (2005). The results showed that up to a content of 5% substitution and for both traces, the residual algaroba wood ash can replace Portland cement without compromising the mortars microstructure and its fresh and hardened state / Com o aumento do seu consumo, o cimento se tornou rapidamente um dos insumos mais consumidos pela humanidade no ?ltimo s?culo. Isso desencadeou um aumento das emiss?es de CO2, uma vez que a produ??o do cimento libera na atmosfera grandes quantidades deste g?s. Somando este fato ao crescente pensamento da preserva??o ambiental, passou-se a buscar alternativas ao cimento, na forma de res?duos, para complementar os seus derivados, sendo uma delas as cinzas. Este trabalho teve como objetivo analisar as propriedades, no estado fresco e endurecido, de argamassas com substitui??o parcial do cimento Portland pela cinza residual de lenha de algaroba (CRLA) produzida pelas olarias do RN. A CRLA foi recolhida e peneirada, onde parte dela foi mo?da e caracterizada em compara??o com a apenas peneirada, sendo caracterizadas quanto a sua composi??o qu?mica, granulometria, finura, massa espec?fica, massa unit?ria e ?ndice de Atividade Pozol?nica. Avaliou-se que a cinza n?o atua como pozolana e que ela mo?da pouco variou em rela??o a apenas peneirada, injustificando seu uso. Adotou-se para este trabalho dois tra?os, sendo 1:3 (cimento : areia fina) e 1:2:8 (cimento : cal : areia m?dia), ambos em volume, usando-se como materiais a CRLA apenas peneirada, o cimento Portland CP II F-32, a cal hidratada CH-I, areia de rio e ?gua da concession?ria local. Para cada tra?o foram adotados percentuais de substitui??o parcial do cimento pela cinza, sendo eles 0% (refer?ncia), 5%, 7%, 10%, 12% e 15%. No estado fresco, as argamassas foram ensaiadas com rela??o ao seu ?ndice de consist?ncia e ? densidade de massa. No estado endurecido, foram ensaiadas com rela??o ? sua resist?ncia ? tra??o na flex?o, ? compress?o e de ader?ncia ? tra??o, e ? sua densidade de massa no estado endurecido. Elas foram tamb?m analisadas por microscopia eletr?nica de varredura e por difra??o de Raios-X. Al?m disso, as argamassas foram classificadas conforme a NBR 13281 (2005). Os resultados encontrados mostraram que, at? um teor de 5% de substitui??o e para ambos os tra?os, pode-se substituir o cimento pela cinza residual de lenha de algaroba sem comprometer as argamassas microestruturalmente e no seu estado fresco e endurecido

Made available in DSpace on 2014-12-17T14:48:16Z (GMT). No. of bitstreams: 1 FelipeMSC_DISSERT.pdf: 3412547 bytes, checksum: 6323164ff4e2d93c2b1596218608b86a (MD5) Previous issue date: 2014-01-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The use of sewage sludge as a raw material falls within the waste recycling key in the current process model environmental sustainability .Waste recycling has been consolidated as a sustainable environmentally sound technical solution, and. Despite showing very variable composition and characteristics, sewage sludge, can be considered as a residue with a high recycling potential in the building sector. In this paper the feasibility of using sewage sludge ash was studied in addition to Portland cement mortar in 1:3 mass considered the standard dash. This gray additions were studied in proportions of 5%, 10 %, 15 %, 20 %, 25% and 30% by mass of cement. The methodology was focused on the characterization of materials by physical, chemical , mechanical , environmental and morphological followed by the production of mortar tests ,and finalized by the characterization tests of mortar in the fresh state, through the consistency index, content of entrained air, bulk density and water retention, and in the hardened state by bulk density, water absorption by capillarity capillarity coefficient, compressive strength, tensile strength in bending ,tensile bond strength and microstructural analysis for percentages of 0 to 20%. After comparing with the standard mortar mortars with addition of ash, it is concluded that the ash of sewage sludge did not impair the integrity and properties of mortars with addition, including increasing resistance to compression and tension, being 20% more indicated percentage. Thus, it becomes feasible the addition of sewage sludge ash in Portland cement mortar for the trait studied / O uso de lodo de esgoto como mat?ria-prima se insere dentro do processo de reciclagem de res?duos, fundamental no modelo de sustentabilidade ambiental atual. A reciclagem de res?duos vem se consolidando como uma solu??o sustent?vel, t?cnica e ambientalmente correta. Apesar de apresentar composi??o e caracter?sticas muito vari?veis, o lodo de esgoto, pode ser considerado como um res?duo com alto potencial de reciclagem no setor da constru??o civil. Neste trabalho foi estudada a viabilidade de utiliza??o de cinza de lodo de esgoto como adi??o em argamassa de cimento Portland no tra?o 1:3 em massa considerado o tra?o padr?o. Foram estudadas adi??es desta cinza nas propor??es de 5%, 10%, 15%, 20%, 25% e 30% em rela??o ? massa de cimento. A metodologia foi centrada na caracteriza??o dos materiais por meio de ensaios f?sicos, qu?micas, mec?nicos, ambientais e morfol?gicos, seguida pela produ??o das argamassas, e finalizada pelos ensaios de caracteriza??o das argamassas no estado fresco, atrav?s do ?ndice de consist?ncia, teor de ar incorporado, densidade de massa e reten??o de ?gua, e no estado endurecido atrav?s da densidade de massa, absor??o de ?gua por capilaridade, coeficiente de capilaridade, resist?ncia ? compress?o, resist?ncia ? tra??o na flex?o, resist?ncia de ader?ncia ? tra??o e da an?lise microestrutural para as porcentagens de 0 e 20%. Ap?s comparar a argamassa padr?o com as argamassas com adi??o da cinza, conclui-se que a cinza de lodo de esgoto n?o prejudicou a integridade e propriedades das argamassas com adi??o, inclusive aumentando a resist?ncia ? compress?o e tra??o, sendo 20% a porcentagem mais indicada. Assim, torna-se vi?vel a adi??o de cinza de lodo de esgoto em argamassa de cimento Portland para o tra?o estudado