Orientador: Kamal Abdel Radi Ismail / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T18:11:18Z (GMT). No. of bitstreams: 1 Lima_JoaoPinto_M.pdf: 3645303 bytes, checksum: 383a85f77a68b7f7e9e69a704c169634 (MD5) Previous issue date: 2005 / Resumo: O conforto ambiental nas edificações é buscado pelos arquitetos como requisito básico na arte de projetar. Estudos de volumetria, o dimensionamento de aberturas, a modelagem dos espaços, o estudo da direção das correntes de ar e a insolação são alguns pressupostos que devam ser observados quando da análise projectual. Ao desenvolvermos a pesquisa sobre material compósito para uso na construção civil utilizando Argamassa de Gesso e Fibra Vegetal, Mauritia vinifera Martius - Palmeira de Buriti-ivan, tem-se como objetivo obter um novo material que possa ser utilizado como revestimento ou elementos de vedação, agregando a este propriedade que conduza à baixa condutividade térmica. A partir da mistura homogeneizada da argamassa de gesso e fibras vegetais em proporção titulada foram produzidas amostras do compósito que submetidas ao Teste do Fio Quente Paralelo determinação da condutividade térmica pela propagação de ondas isotérmicas de calor. Foram determinantes na pesquisa, os estudos da titulação entre as partes agregadas, o teor de umidade, o índice de vazios e a porosidade das amostras. Os testes indicaram que o melhor desempenho obteve-se com as misturas de titulações de 0 % a 35 % de fibra vegetal, M.v.M para o intervalo de tempo compreendido entre 640 a 1280 minutos. / Abstract: The indoor comfort in buildings in researched by the architets as a basic criterion in the art of architecting. Volumetria studies, measuring of archs, space desing, studies of the air commuting as well as insolation are some of the asects which must be focused by the acting of projecting. by the time we developed the research on composite material to be used in the civil enginearing using gipsy and natural fibers, Maurítia vinifera Martius - buriti palm tree, we had as a main gool to obtoin a men material which could the used as a revestiment or elements of tapping, adding to it properties that conduct to a low thermic concdutivity. Based on the homogeous miscture of gipsy and natural fibers in specific proportion of composite were produced samples which were submitted to a " parallel heat wire Test " - part 2. ISO 8894 - 2, which consists in determining of the temperature with the materal samples through a seratch with wire resistor and a thermopair with 30º grade Celsius referential interconnented, respectivey, to an eletric source and a Signal Acquisition Board which determines the thermal conductvity of the materal through the propagation of heat isothermic wawes.The studies of mixing elements of definite proportion between mixed parts, the humidity level and the porosity of the samples have been of great importance to this research. The tests showed that the best performance was obtained by the mixture of and their percentagens of 0 % a 35 of materal fiber for the time between 640 a 1280 seconds. / Mestrado / Refrigeração e Condicionamento Ambiental / Mestre em Engenharia Mecânica

Este estudo consiste em pesquisa realizada com a Agência Brasileira de Promoção de Exportações e Investimentos, agências estrangeiras de promoção de exportações, empresas brasileiras exportadoras e entidade setorial que conduz um programa de promoção de exportações, escolheu-se como foco do estudo o setor de revestimentos cerâmicos. O estudo foca a avaliação de desempenho. Descreveu-se e considerou-se métodos de avaliação utilizados por diversas agências de promoção de exportações. Por meio de questionário, 33 empresas participantes de um programa de promoção de exportações forneceram informações sobre avaliação e satisfação em relação ao programa que participam. Utilizando-se entrevistas dois representantes de agências de promoção de exportações e um representante de entidade setorial forneceram impressões sobre a avaliação de desempenho desses programas. Observou-se que a complexidade do processo de avaliação de desempenho de um programa de promoção de exportações está relacionada às múltiplas origens dos fatores que influenciam esse programa. O desempenho de um programa de promoção de exportações está relacionado tanto a fatores internos ao programa quanto a fatores externos, alheios, não controlados e não previsíveis. Ademais, a análise dos dados revelou que a avaliação de desempenho dos programas de promoção de exportações é complexa e deveria ser conduzida dividindo-se o programa em ações e realizando a avaliação de cada uma das ações individualmente, para então avaliar-se o todo. Verificou-se também as principais oportunidades e ameaças a um programa de promoção de exportações, como forma de propor melhorias. / This study consists of a research with the Brazilian Trade and Investment Promotion Agency, foreign export promotion agencies, Brazilian exporting companies and a sectorial organization that implements an export promotion program, the ceramic tile sector was chosen for this study. The study focuses on performance evaluation. Evaluation methods used by different export promotion agencies were described and considered. Thirty three companies that participate in an export promotion program responded a questionnaire providing information about the evaluation and satisfaction towards the program in which they participate. Two representatives of export promotion agencies and one representative of a sectorial organization were interviewed and gave their impressions of the performance evaluation of these programs. It was observed that the complexity of a performance evaluation process of an export promotion program is related to the multiple origins of the factors that influence this program. The performance of an export promotion program is related to factors both internal to the program and external, uncontrollable and unpredictable. Furthermore, the data analysis showed that performance evaluation of export promotion programs is complex and should be conducted from parts to the whole, meaning that each activity or service of the programa should be evaluated separately. In addition, as a way to propose improvements, the main opportunities and threats to an export promotion program were also verified.

To support the concept of environmentally friendly materials and sustainable development, the low-carbon cementitious materials have been extensively studied to reduce amount of CO2 emission to the atmosphere. One of the efforts is to promote alternative cementitious binders by utilizing abundant alumina-silicate wastes from the industrial sectors (e.g. fly ash or furnace slag), among which “Geopolymer (GP) cement” has received most attention as it can perform a wide variety of behaviours, in addition to cost reduction and less environmental impacts. The most common geopolymer production, fly ash-based, gained some strength with very slow rate at ambient temperature, while the strength is evidently improved when cured in high (above room) temperature, e.g. over 40°C. The major challenge is to step over the limitation of heat curing process and inconvenience in practice. In this study, the testing schemes of (i) GP manufacturing in various processes, (ii) inclusion of ordinary Portland cement (OPC) in GP mixture, called GeoPC and (iii) GeoPC manufactured with dry-mixing method, have been intensively investigated through mechanical testing (Setting time, Compressive strength and Internal heat measurement) and mechanism analysis (XRD, FTIR, SEM and EDXA) in order to develop the geopolymers, achieving reasonable strength without external sources of heat curing. It is found that the proposed (dry) mixing process could have generated intensive heat liberation which was observed as a comparable factor to heat curing from any other external sources, enhancing the curing regime of the mixture. The additional calcium content in the developed GeoPC system not only resulted in an improvement of an early strength by the extra precipitation of calcium compounds (C,N-A-S-H), but also provided a latent heat from the reaction of its high potential energy compounds (e.g. OPC or alkaline activators). The developments from these approaches could lead to geopolymer production to achieve reasonable strength in ambient curing temperature known as “Self-cured geopolymer cement”, without external heat, and hence provide construction industry viable technologies of applying geopolymers in on-site and off-site construction.

Concrete is by far the most widely used construction material worldwide in terms of volume, and so has a huge impact on the environment, with consequences for sustainable development. Portland cement is one of the most energy-intensive materials of construction, and is responsible for some emissions of carbon dioxide — the main greenhouse gas causing global warming. Efforts are being made in the construction industry to address these by utilising supplementary materials and developing alternative binders in concrete; the application of geopolymer technology is one such alternative. Indeed, geopolymers have emerged as novel engineering materials with considerable promise as binders in the manufacture of concrete. Apart from their known technical attributes, such as superior chemical and mechanical properties, geopolymers also have a smaller greenhouse footprint than Portland cement binders. / Research on the development, manufacture, behaviour and applications of low calcium fly ash-based geopolymer concrete has been carried out at Curtin University of Technology since 2001. Past studies of the structural behaviour of reinforced fly ash-based geopolymer concrete members have covered the flexural behaviour of members. Further studies are needed to investigate other aspects of the structural behaviour of geopolymer concrete. Design for both shear and bond are important in reinforced concrete structures. Adequate shear resistance in reinforced concrete members is essential to prevent shear failures which are brittle in nature. The performance of reinforced concrete structures depends on sufficient bond between concrete and reinforcing steel. The present research therefore focuses on the shear and bond behaviour of reinforced low calcium fly ash-based geopolymer concrete beams. / For the study of shear behaviour of geopolymer concrete beams, a total of nine beam specimens were cast. The beams were 200 mm x 300 mm in cross section with an effective length of 1680 mm. The longitudinal tensile reinforcement ratios were 1.74%, 2.32% and 3.14%. The behaviour of reinforced geopolymer concrete beams failing in shear, including the failure modes and crack patterns, were found to be similar to those observed in reinforced Portland cement concrete beams. Good correlation of test-to-prediction value was obtained using VecTor2 Program incorporating the Disturbed Stress Field Model proposed by Vecchio (2000). An average test-to-prediction ratio of 1.08 and a coefficient of variation of 8.3% were obtained using this model. It was also found that the methods of calculations, including code provisions, used in the case of reinforced Portland cement concrete beams are applicable for predicting the shear strength of reinforced geopolymer concrete beams. / For the study of bond behaviour of geopolymer concrete beams, the experimental program included manufacturing and testing twelve tensile lap-spliced beam specimens. No transverse reinforcement was provided in the splice region. The beams were 200 mm wide, 300 mm deep and 2500 mm long. The effect of concrete cover, bar diameter, splice length and concrete compressive strength on bond strength were studied. The failure mode and crack patterns observed for reinforced geopolymer concrete beams were similar to those reported in the literature for reinforced Portland cement beams. The bond strength of geopolymer concrete was observed to be closely related to the tensile strength of geopolymer concrete. Good correlation of test bond strength with predictions from the analytical model proposed by Canbay and Frosch (2005) were obtained when using the actual tensile strength of geopolymer concrete. The average ratio of test bond strength to predicted bond strength was 1.0 with a coefficient of variation of 15.21%. It was found that the design provision and analytical models used for predicting bond strength of lapsplices in reinforced Portland cement concrete are applicable to reinforced geopolymer concrete beams.

Orientador: Wesley Jorge Freire / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-03T23:55:49Z (GMT). No. of bitstreams: 1 MesaValenciano_MarthadelCarmen_D.pdf: 5926517 bytes, checksum: c5fdeb8ea15fe2ab078f58e162b8797d (MD5) Previous issue date: 2004 / Doutorado / Construções Rurais e Ambiencia / Doutor em Engenharia Agrícola

Återvinning av olika varor i dagens samhälle är viktigt för att uppnå minskad miljöpåverkan. Genom att minska uttaget av jungfruligt material och istället använda återvunnet material kan en positiv klimatpåverkan erhållas. Att eliminera linjära materialflöden till fördel för cirkulära flöden kan ekonomisk vinning uppfyllas via affärsmodeller inom cirkulär ekonomi. Byggsektorn står för en betydande del av miljöpåverkan och resursanvändningen, samt genererat avfall i samhället. Därmed finns stora möjligheter att öka cirkularitet genom bättre system för återvinning och därmed främja en mer hållbar framtid. Från NCC gavs ett uppdrag med syfte att undersöka hur stor andel återvunnet material som byggdes in i deras bostadsprojekt. Genom intervjuer med deras leverantörer undersökte denna studie hur stor andel återvunnet material som deras mest använda byggvaror bestod av. Dessa byggvaror var betong, armering, mineralull, cellplast, gips och kök. Vidare undersöktes vilka möjligheter till återvinning som fanns för respektive vara. Syftet var också att, utöver detta, finna mer miljövänliga alternativ för byggbranschen i allmänhet och i synnerhet för de produkter som i dagsläget har störst förbättringspotential. Resultatet visar att andelen återvunnet material för respektive byggvara var varierande, från 0 % till 96 %. Tillsammans bidrar dessa värden till en total andel för NCC’s bostadsprojekt på 8,5 %. Kunskapen och möjligheten till att öka andelen återvunna material som byggvarorna innehåller finns hos leverantörerna. En faktor till detta var att andrahandsvärdet varierade stort samt att det saknas ekonomiska incitament för att sortera byggavfallet. Slutsatsen är därför att det krävs en ökad kostnad för att ta ut jungfruligt material i kombination med att det måste kosta mer att deponera. Med andra ord, förbrukat material ska inte ses som avfall utan som en resurs för att cirkulär ekonomi ska kunna förverkligas i samhället och därmed bidra till positiv miljöpåverkan och förbättrad resurshushållning. Utbildning, samarbete och personligt engagemang är faktorer som krävs för att denna samhällsomställning ska kunna ske. / Recycling of waste is important for the environment in today ́s society. Through less use of new raw material and increased use of recycled material, the climate change can be battled. To eliminate linear flow of material in favour of circular is a part of circular economy. The construction industry contributes to a significant part of both the energy consumption and the amount of waste, and therefore has great opportunities to recycle NCC wants to know how much recycled material they used in their housing projects. Through interviews with their suppliers, this study investigates how much recycled material some of their most used building goods (for example concrete, reinforcement and isolation) contained. Further, the opportunities for recycling of the different types of building goods were analysed. The purpose was also to find more eco-friendly alternatives to the construction industry in general and in particular to the goods which had the largest potential of improvement. The result showed that the proportion of recycled material varied and the total proportion for NCC’s housing projects was low. The knowledge and the opportunities to increase the proportion is known by the suppliers but the majority of the building goods consists a general low proportion. One factor was that the second hand value was varied. Another was that there were no incentive for recycling, which leads to a lack of motivation at the worksite. The conclusion is therefore that waste should be seen as a resource in order to implement circular economy to a greater extent and to contribute to the climate in a positive way. Education, collaboration and personal engagement is factors which is needed to fulfil this adaptation of the society.

Tipos litológicos basálticos provenientes do maciço de fundação da UHE Canoas I foram submetidas a ensaios de caracterização tecnológica com o propósito do seu emprego como material de construção. Foram determinados os valores dos índices físicos (massa específica, porosidade, absorção d\'água), da velocidade de propagação de ondas ultra-sônicas e efetuados ensaios de compressão uniaxial e diametral, entre outros, além de análises petrográficas. Executaram-se, também, ensaios de alterabilidade acelerada (água-estufa, imersão em etileno-glicol) e de alterabilidade natural, tanto em fragmentos de rocha como em testemunhos de sondagens rotativas. São descritos em maior detalhe, os procedimentos utilizados para a realização do ensaio de alterabilidade natural em testemunhos de sondagens rotativas. Analisa-se a influência de uma feição geológica (caixa de falha com cerca de 10 m de espessura e 20º de ângulo de mergulho), presente na fundação, nas propriedades tecnológicas dos tipos litológicos por ela interceptados. São indicados os tipos litológicos selecionados para a utilização como material de construção. / Basaltic litotypes from the rock mass foundation of Canoas I Hydroelectric Power Plant were submitted to technological characterization tests, in order to verify their suitability as construction material. Physical and mechanical properties (density, porosity, water absorption, ultrasonic velocity, compressive and splitting tensile strength, among others) were determined, besides petrographic analyses. Weatherability tests were also performed, not only through wetting-drying cycles and by immersion in ethylene glycol but by outdoor exposure as well, using crushed and core drilled specimens. Detailed procedures for the weatherability test using core specimens from rotary drilling are given. It is analysed the influence of a geological feature (fault zone, about 10 meters thick and 20 degrees dip), that occurs in the rock mass foundation, on the technological properties of these rocks. Basaltic litotypes selected as construction material are then pointed out.

Tipos litológicos basálticos provenientes do maciço de fundação da UHE Canoas I foram submetidas a ensaios de caracterização tecnológica com o propósito do seu emprego como material de construção. Foram determinados os valores dos índices físicos (massa específica, porosidade, absorção d\'água), da velocidade de propagação de ondas ultra-sônicas e efetuados ensaios de compressão uniaxial e diametral, entre outros, além de análises petrográficas. Executaram-se, também, ensaios de alterabilidade acelerada (água-estufa, imersão em etileno-glicol) e de alterabilidade natural, tanto em fragmentos de rocha como em testemunhos de sondagens rotativas. São descritos em maior detalhe, os procedimentos utilizados para a realização do ensaio de alterabilidade natural em testemunhos de sondagens rotativas. Analisa-se a influência de uma feição geológica (caixa de falha com cerca de 10 m de espessura e 20º de ângulo de mergulho), presente na fundação, nas propriedades tecnológicas dos tipos litológicos por ela interceptados. São indicados os tipos litológicos selecionados para a utilização como material de construção. / Basaltic litotypes from the rock mass foundation of Canoas I Hydroelectric Power Plant were submitted to technological characterization tests, in order to verify their suitability as construction material. Physical and mechanical properties (density, porosity, water absorption, ultrasonic velocity, compressive and splitting tensile strength, among others) were determined, besides petrographic analyses. Weatherability tests were also performed, not only through wetting-drying cycles and by immersion in ethylene glycol but by outdoor exposure as well, using crushed and core drilled specimens. Detailed procedures for the weatherability test using core specimens from rotary drilling are given. It is analysed the influence of a geological feature (fault zone, about 10 meters thick and 20 degrees dip), that occurs in the rock mass foundation, on the technological properties of these rocks. Basaltic litotypes selected as construction material are then pointed out.

A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in Science to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, 1985 / This volume contains a record of research carried out over the past two decades into problems associated with civil engineering and mining construction materials. Although the various parts of the work were initiated as a result of problems that arose in the Witwatersrand region, the results of the research have in many cases evoked intense interest from other parts of the world. For example, the work on soluble salts in road bases has been taken up in Saudi Arabia and other desert regions, while that on the stability of waste rock dumps has been adopted as a basis for rock dump design in the United States of America. The research revolves entirely about materials, usually, waste, either produced by the mines and reused or disposed of by civil engineers; or reused to provide support by the mines · themselves. The main aim and end result of the research has been a more effective and efficient use of materials and better protection and control of the local environment. / Andrew Chakane 2021

La construction en terre crue constitue une alternative écologique aux bétons de ciment. Afin de promouvoir son usage, la présente étude s’intéresse à la mise au point de bétons de terre coulables permettant une mise en œuvre analogue à celle des bétons usuels. Dans cette optique, il est nécessaire de conférer au matériau une solidification à court terme (24 h) sans attendre son séchage, afin de permettre un débanchage rapide. La voie explorée pour répondre à cette problématique s’inspire de la technique du Gelcasting utilisée dans le domaine des céramiques techniques. Celle-ci s’appuie sur la gélification de polymères préalablement introduits dans une barbotine céramique pour induire une transition liquide-solide rapide et homogène. Une étude bibliographique complétée par des essais préliminaires a mené à la sélection de l’alginate, un polymère biosourcé non toxique et gélifiant à température ambiante sous l’action de cations multivalents tels que le calcium. Ce polymère s’est révélé très prometteur. Il a permis la réalisation d’éprouvettes de mortier démoulables 24 h après coulage et présentant une résistance en compression de l’ordre de 0,1 MPa, théoriquement suffisante à un mur de 3 m de haut pour tenir sous son propre poids. Une preuve de concept à l’échelle du béton a par ailleurs pu être réalisée sous la forme d’un muret de 40 cm de haut coulé et vibré à partir d’une consistance fluide puis décoffrable en 24 h. Les performances mécaniques et hygrothermiques du matériau sec ont été validées, et la présence du polymère gélifié pourrait améliorer la résistance à l’érosion. De premiers essais ont montré que le procédé pouvait être adaptable à des terres moins calcaires que celle utilisée tout au long de l’étude. / Developing raw earthen construction is nowadays a major environmental issue, due to its low embodied energy compared to Portland cement. A solution would be to use a similar process as cement-based concrete, by casting into formworks. Nevertheless, this is limited by technical difficulties, owing to the fact that earth is not a hydraulic binder. In that perspective, this work focuses on inducing a liquid-solid transition to an earth suspension without waiting for drying, similar to cement-based materials. The approach explored to meet this challenge is inspired by the technique of Gelcasting used in the field of technical ceramics. This relies on the gelation of polymers previously introduced into a ceramic slurry to induce a rapid and homogeneous liquid-solid transition. A bibliographic study supplemented by preliminary tests led to the selection of alginate, a biosourced polymer that is non-toxic. Its gelation is allowed at ambient temperature, via addition of multivalent cations such as calcium ions. This polymer proved to be very promising. It made it possible to produce mortar specimens which could be unmoulded 24 hours after casting. A wet compressive strength close to 0.1 MPa could be reached, theoretically sufficient for a wall of 3 meters high to stand under its own weight. A proof of concept at the concrete scale was then realized as a low wall of 40 cm high casted and vibrated and then unmoulded in 24 hours. Mechanical and hygrothermal performances of the dry material were validated, and the presence of the gelled polymer could improve the resistance to erosion. Initial trials showed that the process could be adapted to low calcareous soils.