▼ 

A durabilidade das estruturas de concreto tem se tornado umas das principais preocupa??es da ind?stria da constru??o civil, principalmente ap?s a ABNT NBR 15.575: Edifica??es Habitacionais ? Desempenho entrar em vigor. Um dos grandes gargalos das estruturas de concreto ? sua baixa resist?ncia ? fissura??o que colocam em risco a sua durabilidade, al?m de permitir que l?quidos e agentes agressivos possam penetrar na matriz e causar danos. Estas fissuras podem ter suas dimens?es aumentadas e expor as armaduras ? ambientes agressivos e consequentemente levar ao colapso estrutural. Assim, a inspe??o, manuten??o e reparos constantes das estruturas s?o indispens?veis. Por?m, por muitas vezes estes reparos s?o onerosos e de dif?cil execu??o. A autocicatriza??o das fissuras do concreto tem ganhado notoriedade como alternativa a estes fatores, que consiste em um fen?meno cujo pr?prio concreto apresenta a capacidade de repara??o de pequenas fissuras de forma expontanea, sem nenhuma interven??o externa. O objetivo deste estudo ? avaliar os efeitos do ADITIVO REDUTOR DE POROSIDADE POR CRISTALIZA??O - ARPC na durabilidade de concretos produzidos com materiais da cidade de Manaus, por meio de pesquisa experimental, analisando a cicatriza??o aut?gena. Foram produzidos quatro concretos com rela??o ?gua/cimento fixa de 0,58, adi??o de ARPC e cimentos, utilizou-se o CPII Z- 40-RS e o CP II E-32. Nestes concretos foram analisadas as propriedades de resist?ncia ? compress?o aos 28 dias sob a carga de ruptura de 100% e 90% para a indu??o de microfissuras nos concretos e posterior avalia??o da cicatriza??o aos 84 dias por meio da resist?ncia ? compress?o. Tamb?m foram avaliadas as propriedades de ?ndice de vazios, absor??o total, absor??o por capilaridade, migra??o de ?ons cloretos e microestrutura do concreto. Como resultado foi constatado que o ARPC apresenta melhor desempenho nos concretos produzidos com o CP II Z-40 RS, principalmente, na idade de 84 dias. Al?m disso, os concretos com a adi??o do ARPC apresentam melhor desempenho no percentual de recupera??o da resist?ncia ? compress?o. Nos ?ndices de vazios e absor??o total o concreto com ARPC e CP II Z-40 RS apresentou os menores valores. Na absor??o por capilaridade os concretos com a adi??o do ARPC apresentaram menores ?ndices de absor??o e menor ascens?o capilar. A microestrutura apresentou cristais t?picos de concretos autocicatrizantes como etringita e carbonato de c?lcio. Na migra??o de ?ons cloretos os concretos produzidos com o CP II E-32 apresentaram as menores concentra??es, o que se deve ao fato da composi??o do cimento com a presen?a da esc?ria de alto forno.

The durability of concrete structures has become one of the main concerns of the construction industry, especially after ABNT NBR 15.575: Housing Buildings - Performance comes into force. One of the major bottlenecks of concrete structures is their low resistance to cracking, which jeopardizes their durability, in addition to allowing liquids and aggressive agents to penetrate the matrix and cause damage. These…

Advisors/Committee Members: Melo Filho, Jo?o de Almeida, http://lattes.cnpq.br/9045456793790448, Vasconcelos, Raimundo Pereira de, http://lattes.cnpq.br/4592922524470036, Ribas, Luciane Farias, http://lattes.cnpq.br/5473986728624292.

▼ 

No nordeste do Amazonas, aflora o caulim pertencente ? forma??o Alter do Ch?o no decorrer das rodovias de acesso aos munic?pios de Manaus, Presidente Figueiredo e Itacoatiara, como a BR-174 e AM-010. Este material quando submetido ? ativa??o t?rmica por calcina??o, sob determinadas faixas de temperatura, resulta em um material amorfo de estrutura cristalina desordenada, denominado metacaulim ou metacaulinita (MK). Apresenta boa reatividade com o hidr?xido de c?lcio presente nas misturas constitu?das de cimento Portland, o que o torna indicado para uso como material ciment?cio suplementar na produ??o de pastas, argamassas e concretos. Assim, a presente pesquisa tem como objetivo geral caracterizar o caulim coletado da BR 174 para a produ??o de metacaulinita e sua utiliza??o como material ciment?cio suplementar em pastas ciment?cias. A possibilidade de utiliza??o em pastas ciment?cias implica na sua caracteriza??o qu?mica e microestrutural atrav?s das t?cnicas de fluoresc?ncia de raios-X, difra??o de raios-x (DRX), an?lise termogravim?trica (TG/DTG/DTA), espectroscopia de infravermelho (FTIR) e microscopia eletr?nica de varredura (MEV). Foram estudadas as transforma??es ocorridas neste material decorrente do tratamento de calcina??o ao qual foi submetido, este ocorreu nas faixas de temperatura de 600 ?C, 650 ?C e 700 ?C nos intervalos de tempo de 1h, 2h e 3h em forno mufla. Por meio da an?lises realizadas foi estabelecida a calcina??o na temperatura de 650 ?C com o tempo de 1h. Na composi??o qu?mica ocorreu a predomin?ncia do ?xido de sil?cio (SiO2) e ?xido de alum?nio (Al2O3), compat?veis com a composi??o do principal mineral identificado no DRX, a caulinita. Para avaliar o comportamento da metacaulinita produzida como material ciment?cio suplementar, a mesma foi utilizada em substitui??o parcial ao cimento em pastas ciment?cias nos teores de 20% a 60%. Estas pastas foram caracterizadas por meio das t?cnicas de DRC, TG/DTG, MEV e resist?ncia ? compress?o nas idades de 7, 28 e 91 dias de cura.

In the northeast of Amazonas, the kaolin belonging to the Alter do Ch?o formation emerges along the access roads to the municipalities of Manaus, Presidente Figueiredo and Itacoatiara, such as BR-174 and AM-010. This material when subjected to thermal activation by calcination, under certain temperature ranges, results in an amorphous material with disordered crystalline structure, called metakaolin or metakaolinite (MK). It has good reactivity with calcium hydroxide present in mixtures made of Portland cement, which makes it suitable for use as supplementary cementitious material in the production of pastes, mortars and concretes. Thus, the present research has the general objective to characterize the kaolin collected from BR 174 for the production of metakaolin and its use as supplementary cementitious material in cementitious pastes. The possibility of use in cementitious pastes implies its chemical and microstructural characterization through the techniques of X-ray fluorescence, X-ray diffraction (XRD), thermogravimetric…

Advisors/Committee Members: Melo Filho, Jo?o de Almeida, http://lattes.cnpq.br/9045456793790448, Manzato, Lizandro, http://lattes.cnpq.br/0677617028146410, Ribas, Luciane Farias, http://lattes.cnpq.br/5473986728624292.

▼ 

A impermeabiliza??o dos solos urbanos afeta diretamente o aumento do escoamento superficial e infiltra??o dos solos. O concreto perme?vel usado em pavimentos apresenta-se como uma a??o mitigadora para essas quest?es. A aus?ncia total de finos ou a redu??o da maior parte dele caracteriza a alta permeabilidade e baixa resist?ncia desse concreto. Na pesquisa ? introduzida a metacaulinita no concreto perme?vel para substitui??o parcial do cimento. O estudo foi realizado com ensaios laboratoriais para verifica??o de resist?ncias mec?nicas e determina??o da taxa de infiltra??o da ?gua. As misturas utilizadas neste estudo consistiram em dois tamanhos agregados e dois tipos de agregados gra?dos. Os ensaios foram realizados em amostras de refer?ncia nas quais n?o havia substitui??o do cimento. Como o trabalho foi desenvolvido para placas de concreto de perme?vel a NBR 16416 (ABNT, 2015) determina que a resist?ncia a tra??o na flex?o alcance o m?nimo 2 MPa. Dessa forma foi estabelecido que as amostras de refer?ncia deveriam alcan?ar um m?nimo de resist?ncia de compress?o 8 MPa. Esse resultado foi atingindo ap?s o ajuste das dosagens e o incremento de 5% de areia. Ap?s atingir o objetivo foi realizada a substitui??o de 15% do cimento por metacaulinita. As caracter?sticas mec?nicas de compress?o depois da substitui??o atingiram resist?ncia ? compress?o simples de aproximadamente 10 MPa e de resist?ncia ? tra??o na flex?o ficou com aproximadamente 2,1 MPa. A taxa de infiltra??o da ?gua ficou com valores em torno de 0,14cm/s. O estudo permitiu avaliar que o seixo e a brita 0 n?o apresentaram diferen?as significativas quanto a resist?ncias mec?nicas e permeabilidade. A substitui??o do cimento por metacaulinita aumentou o consumo de ?gua o que provavelmente est? ligado a maior ?rea especifica desse material. A metacaulinita ? um material fino e como umas das caracter?sticas do concreto perme?vel ? a aus?ncia total o quase total do materiais finos a sua aplica??o n?o diminuiu de forma expressiva a permeabilidade do concreto.

The waterproofing of urban soils directly affects the increase of surface runoff and soil infiltration. The permeable concrete used in pavements presents itself as a mitigating action for these issues. The total absence of fines or the reduction of most of them characterizes the high permeability and low strength of this concrete. In research, metakaolinite is introduced in permeable concrete to partially replace cement. The study was carried out with laboratory tests to check mechanical strength and determine the rate of water infiltration. The mixtures used in this study consisted of two aggregate sizes and two types of coarse aggregates. The tests were performed on reference samples in which there was no replacement of cement. As the work was developed for concrete slabs of permeable, NBR 16416 (ABNT, 2015) determines that the flexural tensile strength reaches the minimum 2 MPa. Thus, it was established that the reference samples should reach a minimum compression strength of 8 MPa. This result was…

Advisors/Committee Members: Campelo, Nilton de Souza, http://lattes.cnpq.br/0154919359639550, Rocha, Francisco dos Santos, Ribas, Luciane Farias.

▼ In the last few years, Brazil has undergone a profound change in the way companies are pro-vided with access to capital markets; this has required greater transparency in the preparation of financial statements and disclosure of accounts. Recent scandals in the history of the finan-cial markets that have involved the practice of accounting choices for the purpose of managing results, require users of this information to be increasingly well prepared. This study seeks to analyze the existence of evidence of management practices in the results of financial state-ments of Brazilian construction companies listed in the BM & FBovespa in the period 2000-2012. The approach adopted for the detection of results management was based on the specif-ic accruals used for panel data methods with the development and employment of a particular model that follows the pattern of the Generalized Linear Mixed Model (GLMM). The re-search revealed that the financial statements published by the Brazilian building constructors for the years 2003-2006 and 2009-2010, show signs of results management with the use of the liquid variable for the amount of real estate sold. The results also suggest that large-sized Bra-zilian building constructors tend to manage their results more than small-sized firms. On the basis of the findings of this research, it is clear that information is not being disclosed that allows an assessment of the quality and performance of companies. There is thus a need for a reform of financial disclosure policies with regard to factors linked to revenue recognition and measurement and in particular, the total budgeted costs of work performed (POC) and the scheduled completion percentage Advisors/Committee Members: Weffort, Elionor Farah Jreige (advisor), CPF:14773512806 (advisor), http://lattes.cnpq.br/3929537799335350 (advisor), Silva, Aldy Fernandes da (advisor), CPF:81684444691 (advisor), http://lattes.cnpq.br/0190161812948354 (advisor).

▼ 

Os processos industriais geram uma variedade significativa de res?duos, de dif?cil decomposi??o final. A proposta dessa pesquisa ? apresentar uma alternativa para a deposi??o final desse res?duo, mais especificamente do poliestireno. Enquanto os pol?meros convencionais s?o formados por estruturas de carbono, geopol?meros s?o constitu?dos de estruturas de s?lica e alumina. Dentre as poss?veis aplica??es, eles podem ser empregados em pastas, argamassas e concretos, em substitui??o ao cimento Portland. Para a adi??o do res?duo industrial na matriz geopolim?rica foi feita sua caracteriza??o, bem como dos precursores do geopol?mero. A an?lise de espectroscopia de infravermelho com transformada de Fourier (FTIR) demonstra que o res?duo utilizado possui em sua composi??o qu?mica uma maior quantidade de di?xido de sil?cio e di?xido de alum?nio. Os resultados da an?lise de difra??o de raios-X (DRX), feitos na amostra de res?duo e na matriz geopolim?rica confirma a composi??o qu?mica fornecida pela ind?stria bem com o processo de geopolimeriza??o. A an?lise de termogravimetria (TG) e derivada de termogravimetria (DTG) demonstram que o res?duo possui uma perda muito pequena de ?gua antes da degrada??o total da amostra. O ensaio de resist?ncia a compress?o evidenciou uma melhora significativa na incorpora??o do res?duo ? matriz geopolim?rica atingindo aos 28 dias cerca de 29,13 MPa (5% res?duo mo?do) e 40,44 MPa (5% res?duo peneirado). O ensaio de flex?o demonstra que a adi??o do res?duo peneirado a matriz resultou em uma melhora na resist?ncia que atingiu 2,07 e uma deforma??o de 0,66mm, cerca de 7,73% maior em rela??o a matriz.

Industrial processes generate a significant variety of residues which is difficult to decompose. The main goal of this research is to present an alternative for the final destination of this materials, specifically polystyrene. While main polymers are based of carbon structures, geopolymers are based of silica and alumina structures. Among possible applications, they can be used in pastes, mortars and concretes, replacing Portland cement. For the addition of the industrial residue in the geopolymer matrix was made its characterization, as well as the precursors of the geopolymer. The Fourier Transform Infrared Spectroscopy (FTIR) analysis demonstrates that the residue used has in its chemical composition a higher amount of silicon dioxide and aluminum dioxide. The results of X-ray diffraction (XRD) analysis on the residue sample and the geopolymer matrix confirm the chemical composition provided by the industry, as well as the geopolymerization process. Thermogravimetry (TG) and thermogravimetry derived (DTG) analysis show that the residue has very little water loss prior to total sample degradation. The compressive strength test showed a significant improvement on the residue?s incorporation to the geopolymer matrix, reaching at 28 days about 29.13 MPa (5% ground residue) and 4.44 MPa (5% screened residue). The flexure test demonstrates that the addition of the sieved residue to the matrix resulted…

Advisors/Committee Members: Manzato, Lizandro, http://lattes.cnpq.br/0677617028146410, Melo Filho, Jo?o de Almeida, http://lattes.cnpq.br/9045456793790448, Pinheiro, Ivanei Ferreira, http://lattes.cnpq.br/4206908141937691.

▼ Globalization, economic estabilization and velocity of information are courrently topics of the modern world. Decision making demands fast e qualified information, therefore, for the accounting professions, a constantly evolution in preparing the managerial information and financial statements. Starting for this principle, it is important that these financial statements permit the full comprehension about the patrimonial situation of a company and also allow to stablish comparative parameters with the other companies which operate in the same sector. However, we could not forget that the elaboration of the financial statements follows some standards that many times do not permit a clear meaning for the accounting users, and specially those who are out of the analyzed companies. Therefore, just as professionals who do the accounting need constantly toimprove themselves and work for the evolution of the discipline, external users of accounting should keep in mind these technical limitations and look for alternatives in order to solve problems. This work aims, based on the study of accountancy of the facts which happens in the estate companies, to show that a serie of factors inherent of their proper activity harm the comprehension of their financial statements when they are analyzed under the optics of the traditional balance sheet analysis, demanding an extra effort, passing for some adjustments in their financial statements in order to adapt for the analysis. Advisors/Committee Members: Castro Neto, Jose Luis de (advisor), CPF:11287780172 (advisor), http://lattes.cnpq.br/5309474902957305 (advisor).

▼ 

A habita??o social de baixa renda sofre atualmente no Brasil um grande d?ficit medido em fun??o da demanda populacional em crescimento, sendo que, atrav?s das pol?ticas p?blicas habitacionais n?o se consegue dar solu??o eficiente em termos de qualidade, tempo de execu??o e facilidades construtivas em conson?ncia com o meio ambiente e os n?veis necess?rios para o correto desempenho da qualidade de vida. Neste contexto, novos sistemas construtivos surgem como solu??es no mercado comercial, como ? o caso dos pain?is sandu?ches pr?-moldados aplicados a moradias de baixo custo. Estes sistemas consideram o planejamento, dimensionamento e detalhamento dos mesmos, sendo um dos motivos de inclus?o dentro desta pesquisa. Baseado nessa problem?tica, este trabalho tem como objetivo desenvolver e caracterizar pain?is sandu?ches constitu?dos por um n?cleo de EPS e faces de ferrocimento. Para atingir esse objetivo, inicialmente foi verificado a utiliza??o de dois tipos de refor?o (malhas met?licas) nas faces de ferrocimento. Com a melhor configura??o do refor?o, produziu-se o painel sandu?che, este ?ltimo foi caracterizado por ensaio mec?nico (flex?o) e ensaio f?sico (t?rmico). Ainda foi projetada uma habita??o de baixo custo em conson?ncia com as carater?sticas bioclim?ticas da cidade de Manaus, na qual ser?o implementados os pain?is sandu?ches como sistema de veda??o e divis?ria.

Brazil is currently suffering a large deficit in social housing, which can be measured based on the population growth, and on the to public housing policies through which it is not possible to provide efficient solutions in terms of quality, execution time and construction methods in line with environmentally friendly approaches and the necessary levels required to achieve a good quality of life. In the light of this, new construction systems have been emerging in the market as solutions, such as precast sandwich panels applied to low-cost housing. This system considers planning, dimensioning and detailing, and for that reason it was included in this research. Based on the problem previously stated, the objective of this work is to develop and characterize sandwich panels made of an expanded polystyrene (EPS) core and ferrocement facings. To accomplish this objective, two types of reinforcement (metallic meshes) for the ferrocement facings were evaluated. With the best reinforcement arrangement, the sandwich panel was produced, and it was characterized by means of mechanical testing (bending) and physical testing (thermal). Moreover, a low-cost housing was designed in line with the bioclimatic characteristics of Manaus, a city in which sandwich panels will be implemented for external and internal walls.

Funda??o de Amparo ? Pesquisa do Estado de Amazonas - FAPEAM

N?o consegui as ?reas do conhecimento de acordo com a tabela CNPq. N?o apareceu nenhum item.

Advisors/Committee Members: Melo Filho, Jo?o Almeida, http://lattes.cnpq.br/9045456793790448, Ribas, Luciane Farias, http://lattes.cnpq.br/5473986728624292, Michels, Caren, http://lattes.cnpq.br/8461410611417570.

▼ This study has as one of the objectives to analyze the posture of the administrators of the building industry in the development of your strategies and actions in the efficient use of natural resources and in the control of the pollution generated by your activities, other objective is to verify if the model of environmental administration Cleaner Production is applicable for the companies of the building industry. For such, it was used as research strategy the method of study of multiple cases with the choice of three companies of the building industry placed among the largest than act in the city of S??o Paulo. The results of the research show that the administrators of the analyzed companies possess knowledge of the need of the environmental preservation inside of an ecological purpose, however, nor all get to visualize as a current competitive advantage inside of a purpose of the marketing. However, only the company that, strategically, it transformed the environmental subject in competitive advantage, it possesses an institutional image of correct company and it has the benefit of to act in customers niches that join value to the environmental preservation. The results still show, that certain characteristics of the analyzed companies, as the concentrated attention on the operational efficiency and the development of technological solutions, it take the an approach of the model of environmental administration Cleaner Production. By and large, for a larger approach, those companies need to treat the environmental subjects in a preventive way, dividing the focus of the production with the neede of the environmental preservation, and together, to intensify actions of environmental education for your stakeholders. Therefore, it is possible to affirm that the model Cleaner Production is applicable to the companies of the building industry analyzed, could become an important tool in the evolutionary process of environmental preservation in those companies. Advisors/Committee Members: Barbieri, Jos?? Carlos (advisor), CPF:13089331853 (advisor), http://lattes.cnpq.br/0041377800166678 (advisor).