Bridges with orthotropic steel decks have been built across the world over the past 60 years because they provide high strength and stiffness at a relatively low cost. However, a number of these bridges have sustained fatigue fractures. The investigation described in this thesis was carried out in order to identify cost-effective fatigue crack mitigation techniques by using the deck surfacing to reduce the stresses in the steel deck. Epoxy asphalt with an expanded metal mesh was investigated with small- and large-scale laboratory tests. Finite element analyses were also performed. The small scale tests conducted at different temperatures and loading frequencies showed that asphalt stiffness increased with decreasing temperature and faster loading. The expanded metal mesh in the epoxy asphalt layer noticeably increased asphalt stiffness. In the large scale tests and finite element analyses, critical loading positions to cause stress concentrations at the fatigue prone rib-to-deck welded connections were determined with different tyre configurations. The stress reduction due to the deck surfacing was estimated for the critical loading positions. The full scale test specimen was subjected to actual truck tyres. With the effectiveness of mitigation techniques for fatigue cracks on orthotropic steel bridge decks known, a probability-based fatigue lifetime evaluation methodology using Monte Carlo simulation was developed. The deck surfacing effects with seasonal and hourly temperature variations were considered. The fatigue lifetime extension using the epoxy asphalt was quantified. For a particular bridge, cost-effective maintenance scenarios were investigated. A simple calculation method for fatigue lifetime was introduced for engineers or bridge owners to assist understanding of decision support tool concepts.

Orientador: Sandro Donnini Mancini / Coorientador: Bruno Fernando Gianelli / Banca: Diogo Aparecido Lopes Silva / Banca: Gerson Araújo de Medeiros / Banca: Ricardo Gabbay de Souza / Banca: Michel Xocaira Paes / Resumo: Neste trabalho foi realizada a Avaliação do Ciclo de Vida (ACV) do processo de logística reversa da destinação de embalagens vazias de agrotóxicos empregado atualmente no Brasil. Esse procedimento apresenta um fluxo que se inicia na entrega das embalagens, após o uso, em postos de recebimento que encaminham a unidade maiores, denominadas centrais que, por sua vez, remetem os invólucros a incineradoras e recicladoras associadas ao órgão que administra o processo. Para avaliar esse procedimento, inicialmente, foi realizada uma ACV da fronteira final do sistema. Para tal foram utilizados dados de quantidade de embalagens destinadas, por tipo, e quantidade de viagens realizadas entre centrais e destinadoras, nos anos de 2014, 2015, 2016 e 2017 de quatro unidades de recebimento, localizadas nas cidades de: Capão do Leão/RS, Ituverava/SP, Piedade/SP e Piracicaba/SP. O método utilizado foi o Midpoint (H)/World ReCiPe H/H (2016). Nesse primeiro momento foram simulados o cenário atual e outros cenários com tratamentos diferentes dispensados às embalagens. Os resultados mostraram que as distâncias percorridas entre centrais e destinadoras prejudicam substancialmente o objetivo inicial do processo de redução de impactos ambientais. Um cenário em que são utilizadas recicladoras e incineradoras mais próximas às centrais foi capaz de reduzir os impactos ambientais em todas as categorias estudadas, para todos os anos e unidades de recebimento, atingindo, por exemplo, na central de Capão do ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this thesis it was carried out the Life Cycle Assessment (LCA) of the reverse logistics processes for the destination of empty agrochemical containers currently employed in Brazil. This procedure was created to reduce environmental damager and the process flow starts from the delivery of packages, after use, at the receiving stations that send them to larger units, called plants. In turn, they send the casings to the incinerators and recyclers associated to the body that administers the process. In order to evaluate this procedure, initially a LCA of the final frontier of the system was performed. For this purpose, we used data on the number of packages destined, by type and number of trips made between central and destination, in 2014, 2015, 2016 and 2017 of four reception units located in the cities of: Capão do Leão / RS, Ituverava / SP, Piedade / SP and Piracicaba / SP. The method used was Midpoint (H) / World ReCiPe H / H (2016). In this first moment the current scenario and other scenarios with different treatments to the packages were simulated. The results showed that the distances traveled between centrals and destinantions substantially undermine the initial objective of the process of reducing environmental impacts. A scenario with recyclers and incinerators closer to the plants, was able to reduce environmental impacts in all categories studied, considering all the years and receiving units, reaching, for example, the Capão do Leão plant - the farthest one amon... (Complete abstract click electronic access below) / Doutor

Orientador: Sandro Donnini Mancini / Banca: Gerson Araujo de Medeiros / Banca: José Lázaro Ferraz / Resumo: Os equipamentos eletroeletrônicos fazem parte de uma indústria em expansão na qual a constante inovação torna-se rapidamente obsoletos. O aumento de resíduos eletroeletrônicos incitou várias políticas de descarte e reciclagem, mas ainda faltam estudos qualitativos para que se possa entender quais são os maiores impactos no meio ambiente e o que se fazer para amenizá-los. A pesquisa consistirá na avaliação do desempenho ambiental de dois modelos de impressoras. Será baseada na metodologia de Avaliação de Ciclo da Vida e na posterior simulação de cenários de disposição final. Fez-se uma caracterização de materiais, peças e massas. A impressora A apresentou um impacto 35% maior que a impressora B devido às suas diferenças de composição e funcionalidades. Nos dois casos, o material em maior quantidade e responsável pela maior parcela do impacto calculado foi o HIPS (Poliestireno de Alto Impacto) e a maioria dos impactos pode ser vista na categoria de Combustíveis Fósseis / Abstract: The electronic equipments are part of a booming industry where constant innovation makes them quickly obsolete equipment. The increase of electronic waste concern generated various disposal and recycling policies but there is still a lak of quantitative studies on the impacts of such products so that they can understand what the major impacts on the environment and what can be done to mitigate the impacts. This research consisted in the characterization of two printers of different models regarding to materials, parts, and weight and using the tool life cycle analyses to quantify the environmental impact of each of them separately and combined. To complete the study a simulation disposal scenarios was made with one of the printers to understand the impacts of recycling, reuse and disposal in a sanitary landfill. The printer. A presented a 35% greater impact than printer B due to their differences in composition and functionality. In both cases the material in greater quantity and responsible for most of the impact was HIPS (High Impact Poltystyrene) and the largest share of the impacts can be seen in the category of fossil fuels / Mestre

Made available in DSpace on 2015-03-03T11:52:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-23Bitstream added on 2015-03-03T12:06:27Z : No. of bitstreams: 1 000803503.pdf: 1104411 bytes, checksum: 85ccc688e0d741d11d63b00619c11c11 (MD5) / Os equipamentos eletroeletrônicos fazem parte de uma indústria em expansão na qual a constante inovação torna-se rapidamente obsoletos. O aumento de resíduos eletroeletrônicos incitou várias políticas de descarte e reciclagem, mas ainda faltam estudos qualitativos para que se possa entender quais são os maiores impactos no meio ambiente e o que se fazer para amenizá-los. A pesquisa consistirá na avaliação do desempenho ambiental de dois modelos de impressoras. Será baseada na metodologia de Avaliação de Ciclo da Vida e na posterior simulação de cenários de disposição final. Fez-se uma caracterização de materiais, peças e massas. A impressora A apresentou um impacto 35% maior que a impressora B devido às suas diferenças de composição e funcionalidades. Nos dois casos, o material em maior quantidade e responsável pela maior parcela do impacto calculado foi o HIPS (Poliestireno de Alto Impacto) e a maioria dos impactos pode ser vista na categoria de Combustíveis Fósseis / The electronic equipments are part of a booming industry where constant innovation makes them quickly obsolete equipment. The increase of electronic waste concern generated various disposal and recycling policies but there is still a lak of quantitative studies on the impacts of such products so that they can understand what the major impacts on the environment and what can be done to mitigate the impacts. This research consisted in the characterization of two printers of different models regarding to materials, parts, and weight and using the tool life cycle analyses to quantify the environmental impact of each of them separately and combined. To complete the study a simulation disposal scenarios was made with one of the printers to understand the impacts of recycling, reuse and disposal in a sanitary landfill. The printer. A presented a 35% greater impact than printer B due to their differences in composition and functionality. In both cases the material in greater quantity and responsible for most of the impact was HIPS (High Impact Poltystyrene) and the largest share of the impacts can be seen in the category of fossil fuels

Current life cycle assessment tools are often deficient in assisting design for sustainable manufacturing efforts. Integrating an improved assessment method into a decision support framework will provide a means for designers and engineers to better understand the impacts of their decisions. A unit process modeling-based sustainability assessment method is presented to assist design decision making by accounting for and quantifying economic, environmental, and social attributes. A set of these sustainability metrics is defined as a basis for comparison of component design alternatives. The method is demonstrated using two titanium component production alternatives that represent typical design for manufacturing scenarios. The modeling method significantly increases the resolution of sustainable manufacturing metrics over conventional assessment techniques, and is one aspect of the overall decision support framework developed. Additionally, fixed sum importance weighting, weighted sum modeling, and scenario analysis were selected as easily employed and transparent design decision techniques to provide the remaining elements of the framework. The demonstration of the decision support framework for titanium component manufacturing illustrates that the sequential approach developed can assist engineers in developing more sustainable components and products. / Graduation date: 2012