Bygg- och fastighetssektorn står idag för en femtedel av koldioxidutsläppen och en dryg tredjedel av energianvändningen inom Sveriges gränser, vilket pekar på en stor utvecklingspotential. Miljöcertifieringen NollCO2 ska på ett mer holistiskt sätt driva på klimatarbetet i byggprojekt genom att ställa krav på att växthusgasutsläppen under bygg- och driftskedet reduceras, men också att kvarvarande klimatpåverkan balanseras med klimatåtgärder mot ”netto noll”. Forskningen lyfter fram att det i hållbara byggprojekt är svårare att hålla tidplanen och kostnadsbudgeten, där detta bland annat beror på långsamt beslutsfattande, kommunikationssvårigheter och projekteringsomtag. Dessa problem har nämnts i projekt med lägre ställda hållbarhetsambitioner än de som NollCO2 har. NollCO2-certifieringen har dessutom ett annat upplägg än dess förlagor. Dessa anledningar gör det intressant att undersöka vad som gör ett NollCO2-certifierat projekt genomförbart och framgångsrikt. Examensarbetets mål har varit att genom en litteraturstudie och en fallstudie av ett NollCO2-certifierat byggprojekt (1) identifiera vilka projektledningsrelaterade nyckelfaktorer som är viktiga ur ett tids- och kostnadsperspektiv i projekteringsskedet av ett byggprojekt med hög hållbarhetsprofil och (2) analysera de identifierade nyckelfaktorerna genom att ta reda på: ·       Vad varje nyckelfaktor innebär ·       Varför nyckelfaktorn är viktig för byggprojekt med hög hållbarhetsprofil ·       Hur projektgruppen i praktiken får nyckelfaktorn att fungera. Litteraturen som studerades handlade bland annat om grunderna i olika miljöcertifieringar och byggprocessen, som sedan ledde till att studera de fyra termerna tydliga målsättningar, kommunikation, tidig samverkan och upparbetade relationer. De personer som intervjuades var beställarens Projektchef, projektledaren, byggentreprenörens projektchef, platschefen, projekteringsledaren, hållbarhetssamordnaren och arkitekten. De fyra projektledningsrelaterade nyckelfaktorerna identifierades som tydliga målsättningar, kommunikation, tidig samverkan och upparbetade relationer, vilka visades inbördes relaterade varandra. En tydlig målsättning definieras som förståeligt, gemensamt och etablerat i tidigt skede. Där är det även viktigt att ett syfte med uppgiften finns för att förstå målet. Det kan uppnås genom bland annat ett bra och tydligt måldokument. Bra kommunikation i ett byggprojekt handlar om att ha bra informationsdelning mellan de olika aktörerna i ett byggprojekt; både muntligt genom att ge rätt information till rätt person vid rätt tid, och skriftligt/digitalt genom att ha uttalade sätt för hur handlingar, styrdokument och annat inom byggprojektets ramar ska kommuniceras ut. Tidig samverkan är när en byggentreprenör och rätt konsulter blir anlitade i ett tidigt skede. Som en gemensam organisation, likt ett fiktivt bolag sätts all nödvändig kompetens in i början av projekteringen för att minska risken för fel och ändringar. Upparbetade relationer är relationer som på ett eller annat sätt finns med andra inom branschen. Det underlättar att arbeta i en grupp där relationer är etablerade och styrkor och svagheter kända. Ingen av de fyra identifierade nyckelfaktorerna är i sig nya eller unika för CO2-certifierade projekt. Däremot pekar resultaten från studien på att dessa nyckelfaktorer är extra viktiga att beakta i projekteringsskedet av ett projekt där NollCO2-certifieringens krav ska uppfyllas eftersom det ställer krav på en högre grad av samordning mellan medverkande i projektet. / The Swedish construction- and real estate sector today account for a fifth of carbon dioxide emissions, a third of the energy consumption and two fifths of waste in Sweden, which points at a large development potential. The environmental-certification NollCO2 aims to involve sustainability in a more holistic way by establishing an emission limit for the specific construction project, and then undercut that limit by 30%. Research shows that it is harder to keep schedule and budget in sustainable construction projects, where some of the reasons is slow decision-making, communication-difficulties, and design-retakes. These problems have been mentioned in construction projects with less ambitious sustainability-goals than NollCO2 has. The NollCO2-certification is also set up in a different way than its predecessors. These reasons makes it intriguing to research what makes a NollCO2-certified construction project feasible and successful.  The goal of the thesis project has been to (1) identify what project management related key-factors is important from a time- and cost perspective in the design-stage of a construction project with high a sustainability-profile and (2) analyze the identified key-factors by answering; ·       What each key-factor implies ·       Why the key-factor is important for construction projects with a high sustainability-profile ·       How the project-organization get the key-factor to work practically  The studied literature brought up the basics of different environmental-certifications and the construction process, which led to studying the four terms clear goalsetting, communication, early partnering and worked up relationships. The different roles that were interviewed was the clients projectchief, project manager, the contractors projectchief, site manager, design manager, sustainability coordinator, and architect.  The four project management related key-factors were identified (1) as clear goalsetting, communication, early partnering and worked up relationships.  These four key-factors were analyzed (2) with the help of the questions stated earlier. A clear goal is defined as understandable, common, and established in an early stage. It’s also important to understand the intention of the assignment to understand the goal. The clear goals can for instance be achieved using a good and clear goalsetting-document. Good communication in a construction project is all about sharing information with one another correctly. Verbally by giving the right information to the right information at the right time. Written by using certain ways or systems of sharing plans, control documents and other things within the project framework. Early partnering is when a contractor along with the right consultants gets involved at an early stage to contribute with their expertise. By working as a joint organization, almost as a fictive company you can put all the necessary competence in the design stage and therefore minimize the number of errors and changes. Worked up relationships is relations that exists in some way with other people in the construction industry. It’s easier to work in a group that you already have a relationship with, where you know each other’s strengths and weaknesses.

La presente investigación analizó las propiedades físicas y mecánicas de bloques de concreto para muros portantes con plástico de residuos electrónicos como reemplazo del agregado grueso, el plástico que se utilizó fue el Poliestireno de Alto Impacto (HIPS) verificando que los resultados de resistencias cumplen con la normativa peruana E.070. El reemplazo se realizó en porcentajes volumétricos de 5%, 10% y 15% respecto del agregado grueso, los bloques se sometieron a ensayos de variación dimensional, alabeo, absorción, succión, resistencia a compresión, resistencia a compresión en prismas y resistencia a compresión en muretes; en los ensayos de propiedades físicas los resultados cumplen con la normativa en cada uno de los reemplazos, sin embargo en las propiedades mecánicas los resultados obtenidos muestran una conservación de la resistencias con poco porcentaje de reemplazo, lo cual se comprobó a través de un análisis estadístico y contrastivo, quedando demostrado que el porcentaje de sustitución más apropiado es el 5%, en el cual las propiedades mecánicas presentan resistencias con diferencias poco significativas respecto del bloque patrón, siendo viable el uso del plástico electrónico. / This research analysed the physical and mechanical properties of concrete blocks for load-bearing walls with e-waste plastic as a replacement for the coarse aggregate, the plastic used was High Impact Polystyrene (HIPS), verifying that the strength results comply with Peruvian standard E.070. The replacement was carried out in volumetric percentages of 5%, 10% and 15% with respect to the coarse aggregate, the blocks were tested for dimensional variation, warping, absorption, suction, compressive strength, compressive strength in prisms and compressive strength in walls; In the physical properties tests, the results comply with the standards in each of the replacements; however, in the mechanical properties, the results obtained show a conservation of the resistances with a low percentage of replacement, which was verified through a statistical and contrastive analysis, demonstrating that the most appropriate replacement percentage is 5%, in which mechanical properties present resistances with little significant differences with respect to the standard block, being viable the use of electronic plastic.

Este trabajo experimental propone una solución sostenible para la construcción mediante el uso de ladrillos hechos de micelio fúngico y aserrín. La idea surge del problema ambiental que enfrenta el mundo debido a la explotación de materias primas no renovables para la fabricación de materiales de construcción convencionales. En este estudio, el micelio de Pleurotus Ostreatus se mezcló con tres sustratos de diferentes granulometrías: aserrín (MA), virutas de madera (MB) y una mezcla de aserrín y virutas (MC), en proporciones de 10% de micelio y 90% de sustrato. Después de dejar la mezcla en condiciones húmedas durante unos 30 días para permitir un crecimiento óptimo del micelio, se extrajo del molde como un solo bloque sólido y se sometió a pruebas físicas y mecánicas. Los resultados de estos ensayos arrojaron una resistencia a la compresión máxima de 2.81 kg/cm2 perteneciente a la MC y una mínima de 2.38 kg/cm2 para la MA; un módulo de rotura máximo de 3.53 kg/cm2 perteneciente a la MC y un mínimo de 2.59 kg/cm2 para la MA; una densidad de 0.08 g/cm3 para a la MA, 0.15 g/cm3 para la MB y 0.19 g/cm3 para la MC; en absorción se obtuvo un 63.95% para la MA, 30.11% para la MB y 15.4% para la MC; respecto al análisis de costos de producción se halló que es un 28% más barato que un ladrillo convencional de arcilla y un 37% más barato que un ladrillo casetón de tecnopor. En conclusión, este estudio demuestra que el uso de ladrillos hechos a base de micelio fúngico y aserrín podría ser una alternativa sostenible y rentable para el sector construcción.

This dissertation delves into the exploration of calcium carbonate polymorphs and silica-based materials upcycled from waste cement paste using a two-step extraction and carbonation process as supplementary cementitious materials (SCMs) to simultaneously achieve solid waste upcycling and carbon sequestration in the built environment. With the growing urgency to mitigate carbon emissions associated with the cement industry—one of the largest industrial contributors to anthropogenic CO₂ emissions globally—there is a pressing need to develop low-carbon alternatives that do not compromise the performance of concrete. This research is motivated by the potential of marrying carbon capture, utilization, and storage (CCUS) and alternative SCMs through CO₂ mineralization of industrial by-products and waste materials to lower the embodied carbon of cement and concrete. This approach addresses two critical issues: the reduction of construction and demolition (C&D) waste and the creation of highly reactive SCMs that can partially replace ordinary Portland cement (OPC). The dissertation is structured into two primary parts: the first focuses on the synthesis and potential applications of calcium carbonate polymorphs that can be derived from CO₂ utilization, and the second on the upcycling of waste cement paste into reactive silica-based materials. The first part (Chapters 2, 3, and 4) of the dissertation centers on three anhydrous calcium carbonate polymorphs, calcite, aragonite, and vaterite, which were synthesized under controlled laboratory conditions. These polymorphs were first characterized comprehensively using analytical techniques including scanning electron microscopy (SEM) to observe their distinct morphologies, X-ray diffraction (XRD) to determine their crystalline structures, laser diffraction (LD) to analyze their particle size distribution, and Brunauer-Emmett-Teller (BET) analysis to measure their specific surface areas. The rheology, hydration, and stability of these polymorphs were then investigated after they were used as substitutes for Portland cement (OPC) in cement pastes at 10 wt% or 20% replacement level. In Chapter 2, detailed rheological analyses were conducted, including rotational and oscillatory shear tests, to evaluate the influence of these polymorphs on the viscosity, yield stress, and structural buildup of cement pastes. Aragonite, with its needle-like crystals, was found to significantly enhance the static yield stress and structural build-up rates while having a minimal impact on dynamic yield stress, making it particularly suitable for applications requiring high thixotropy, such as 3D printing of concrete. In Chapter 3, the polymorphs were found to affect the hydration kinetics of the cement pastes, with aragonite exhibiting the most pronounced accelerating effect, thereby contributing to faster early-age strength development. The differences in thermodynamic stability of the three polymorphs also resulted in slightly different phase assemblages as revealed via thermodynamic modeling, indicating potential beneficial effects of using metastable aragonite and vaterite in cement-based materials. The metastable vaterite was also found to be stabilized in cement systems despite its instability and tendency to convert to calcite in aqueous environments. In Chapter 4, the mechanisms underlying the stabilization of vaterite in cement paste were explored with carefully designed experiments to construct model systems to decompose the complex cement-based systems and isolate dominating factors. The deposit and growth of cement-hydrated phases on the surface of vaterite and calcite seeds were found to be the dominant mechanisms preventing the transformation of vaterite to calcite, stabilizing metastable vaterite even in the presence of calcite seeding. The second part (Chapter 5) of the dissertation investigates the reactivity of amorphous silica-based materials extracted from waste cement paste using a pH swing process as alternative SCMs. The upcycling process involves the leaching of calcium from waste cement paste, followed by a pH swing to precipitate undesired elements to isolate calcium for CO₂ mineralization. The resulting materials, referred to as "residue" and "precipitate," were thoroughly characterized and found to exhibit strong pozzolanic reactivity. When used as 10% replacements for OPC, these upcycled materials significantly improved the compressive strength of cement pastes, particularly at early ages. The study also explored the phase assemblages formed in these cement pastes after hydration via XRD and the chemical circularity of silicate structures during the upcycling and reincorporation processes. The results indicated that the incorporation of these upcycled SCMs can contribute to the hydration of cement pastes and enhance their mechanical properties, which proved the feasibility of using these upcycled materials as alternative SCMs. Overall, this dissertation presents a comprehensive study on the potential of calcium carbonate polymorphs and upcycled silica-based materials as alternative SCMs to lower the embodied carbon of cement-based materials. Calcium carbonate polymorphs can be incorporated into cementitious materials to improve their rheological properties, hydration behavior, and mechanical performance, while amorphous silica-based materials exhibited high pozzolanic reactivity and contributed to the enhancement of compressive strength. This research paves a new way to decarbonize the built environment through the combination of solid waste upcycling and carbon sequestration, contributing to the global efforts to reduce the carbon footprint of the cement industry and promote a circular economy within the construction sector.

L’introduction du développement durable apporte de nouvelles préoccupations environnementales au niveau de la construction et de la rénovation résidentielles, une industrie qui représente un marché économique important au Canada. En plus d’engendrer plusieurs impacts sur l’environnement, la conception actuelle ne permet pas d’accommoder le changement initié par l’évolution des pratiques, les avancées technologiques, mais également par l’évolution des patrons de vie des occupants. Dans un premier temps, la revue de littérature dresse le portrait de l’industrie de la construction, rénovation et démolition (CRD) au Canada, ainsi que le profil de gestion des débris de CRD. Ensuite, une analyse documentaire traite de différents outils de conception développés pour améliorer la performance du secteur : 3RV-E, écoconception, écoconstruction et LEED®. De plus, la recension des écrits permet également de cerner les concepts d’adaptabilité et de flexibilité au niveau du bâtiment et dans les approches et mouvements émergents en architecture. Cette démarche nous amène à établir l’hypothèse que l’intégration des critères d’adaptabilité et de flexibilité au niveau du logement aurait pour effet d’améliorer l’adéquation entre les besoins évolutifs des occupants et les nouvelles considérations environnementales. Au niveau méthodologique, l’analyse du cycle de vie simplifiée par l’Eco-indicator99 encadre l’analyse environnementale de l’ossature de trois types de construction de cloison. De cette évaluation, on conclut que c’est la construction traditionnelle à ossature de bois qui produit le moins d’impacts. Dans l’ordre suivant la proposition de construction de cloison à ossature d’aluminium, plus adaptable et flexible, et finalement la construction à ossature d’acier qui est le système le plus dommageable. Par contre, en intégrant le facteur temporel, cette analyse démontre que l’intégration de l’adaptabilité et de la flexibilité procure plusieurs cycles de vie et de rénovation au produit et à ses composantes. Finalement, ces concepts offrent également le potentiel de diminuer les impacts générés par la construction et la rénovation, un constat qui mériterait d’être abordé dans une approche plus systémique. / The introduction of sustainable development brings new environmental concerns on an important Canadian market industry: construction and residential renovation. Not only does the current concept have a considerable impact on the environment, it also can’t follow up with the development of practices, technologies and occupants’ lifestyle. First, a literature review draws a picture of the construction, renovation and demolition industry (CRD) in Canada and it outlines the CRD rubbles management profile. Then a documentary analysis drafts different concept tools that were developed to improve the industry’s performance. They are 3RV-E, ecodesign, sustainable construction and LEED®. The papers review also explores the adaptability and flexibility concepts on the construction sector and on the emerging architectural trend. This approach brings us to the hypothesis that the integration of the adaptability and flexibility criteria to the housing sector will improve the adequacy between the progressive needs of the occupants and the new environmental issues. On a methodological perspective, the simplified lifecycle analysis performed with the Eco-indicator99 overviews the environmental analysis of three types of partition construction. The outcome of this evaluation is that the one with the less environmental impact is the traditional construction with a wooden framework, followed by the construction with an aluminum framework which is adaptable and flexible, and in third place, the construction with a steel framework which is the most harmful to the environment. On the other hand, adding the time factor to this analysis demonstrates that the integration of the adaptability and flexibility criteria brings a number of renovation and life cycles to the product and its components. In the end, these concepts present us with a potential of reducing the impacts of construction and renovation on the environment and that’s an assessment that would need to be approached systematically.

A indústria da construção, nomeadamente no setor da edificação, baseia-se essencialmente em métodos de construção tradicional. Esta indústria é caracterizada pela elevada quantidade de recursos que consome, pela quantidade de resíduos que produz, a sua implicação na economia dos países e à sua inter-relação com a sociedade. Esta realidade é de todo incompatível com os desígnios do desenvolvimento sustentável, nos quais se procura a correlação harmoniosa entre as vertentes ambientais, sociais e econômicas. O desafio da sustentabilidade colocado à atividade da construção tem motivado abordagens distintas, não só por parte das várias especialidades da engenharia, como também da arquitetura. Neste sentido, o presente trabalho propôs-se a desenvolver uma Ferramenta que, de uma forma coordenada e integrada permita orientar o desenvolvimento do projeto para soluções sustentáveis ao longo das várias fases do ciclo de evolução de um projeto. Foi desenvolvida recorrendo a uma pesquisa bibliográfica sobre o tema da gestão de projetos e sobre o sistema de certificação de sustentabilidade Leadership in Energy and Environmental Design (LEED). Para além disto, foram ainda incorporados alguns requisitos normativos, obtidos por meio de normas brasileiras ABNT, normas Americanas e normas Europeias. Pensa-se que da adequada aplicação desta ferramenta, os objetivos definidos pelo promotor da obra em termos de sustentabilidade, poderão ser mais facilmente atingidos pela equipa de projetista através da consideração antecipada de medidas e soluções de sustentabilidade nas diferentes fases de desenvolvimento do projeto permitindo assim, um melhor desempenho do edifício ao nível da construção sustentável. / The construction industry, particularly in the building sector, is based mainly on traditional construction methods. This industry is characterized by excessive consumption of resources, the amount of waste it produces, its implication in the economy of countries and their relationship with society. This reality is entirely incompatible with the aims of sustainable development, which seeks a harmonious relationship between the environmental, social and economic aspects. The sustainability challenge faced by the construction activity has motivated different approaches, not only by the various engineering specialties, but also by the architecture. In this sense, this paper aimed to develop a model in a coordinated and integrated manner to guide the development of the project to sustainable solutions throughout the various stages of the project life cycle. It was developed using a literature review about the topic of project management and sustainability assessment tool Leadership in Energy and Environmental Design (LEED). Furthermore, and to improve the effectiveness of the Model, it was been incorporated some standardisation requirements, obtained by Brazilian standards ABNT, American standards and European standards. Through proper application of this tool, the goals set by Owner of the work, in terms of sustainability, can be more easily achieved by the project design team through timely consideration of measures and sustainability solutions at different stages of project development. Allowing a better performance of the building in terms of the sustainable construction.

Este trabalho analisa, por meio de método experimental, a viabilidade de apropriar a produção de painel alveolar de concreto armado para aplicação em habitações de interesse social. Compara os processos industriais praticados para a produção deste elemento com alternativas inovadoras proporcionadas pela incorporação de fôrma interna, ou núcleo alveolar, que permite apropriar a tecnologia para aplicação em diferentes escalas conforme as características de cada empreendimento. Avalia a execução, a conectividade e o desempenho mecânico em relação à resistência à compressão do painel alveolar. Contribui com contexto de construção sustentável e o aproveitamento de resíduos industriais e conclui que o núcleo alveolar incorporado configura inovação tecnicamente viável no processo de produção do painel alveolar que pode ser utilizado em sistemas de fechamento e superestruturas (paredes portantes e lajes) em habitações. / This work analyzes the viability of appropriate the hollow core slab production for social housing construction, by means of an experimental method procedure. It compares the industrial process with innovated alternatives proportionate by internal hollow nuclear mould incorporate which provides technology appropriation for several production scales according to construction portage. Evaluate the execution, connectivity (with hydraulic and electric systems) and compressive strength of hollow core slabs. The researchs contributions is relate with the context of sustainable construction and the use of industrial waste as construction raw materials and it concludes that internal hollow nuclear mould incorporate is technically viable in hollow core slabs production´s process and this precast element could be applied in wall´s and slabs for housing construction.

As coberturas verdes fazem parte da arquitetura vernacular há séculos como solução para regulação térmica das edificações, retardando a transferência de calor para o ambiente interno e, no inverno, retardando as perdas de calor dos ambientes internos para o exterior da edificação (International Green Roof Association - IGRA). Em se adotando cobertura verde em edificações supõe-se haver economia no consumo de energia para se obter condições de conforto térmico nos ambientes. Baseado nessa suposição foi realizada uma pesquisa experimental onde, por meio de um estudo comparativo entre dois tipos de cobertura: a verde e a de telhas cerâmicas comprovou-se o potencial de economia de energia. A análise do comportamento térmico das coberturas verdes foi realizada por meio de coleta de dados de variáveis ambientais, durante um período de 10 meses, de um protótipo instrumentado, construído no Departamento de Engenharia de Construção Civil da Escola Politécnica da USP, São Paulo. Os dados levantados foram comparados com os dados de um segundo protótipo de mesmas dimensões e igualmente instrumentado, com cobertura cerâmica, sob as mesmas condições ambientais. A comparação dos resultados e análises em dias e episódios representativos de cada estação comprovaram a eficiência das coberturas verdes para retardar o ganho térmico da edificação. Espera-se que os resultados sejam incentivadores à larga aplicação dos telhados egetados, o que trará diversas vantagens para população. / Green roofing is been a part of the vernacular architecture for centuries as solution for constructions thermal regulation. It is known that they delay the heat transfer from the outside to the inside of the building, and during winter, they delay the heating loss from the inside to the outside of the building (International Green Roof Association - IGRA). By adopting green roofs in buildings, one assumes that there is economy in energy consumption to obtain conditions of thermal comfort in inner environments. Based on this assumption, an experimental research was accomplished where, through a comparative study between two types of roofing systems: green and ceramics, it was determined this energy saving potential of green roofs. The analysis of the green roofing thermal behavior was realized through data collection of environmental variables, during the period of ten months, from an instrumented prototype constructed at the Polytechnic School of the University of São Paulo, São Paulo. The collected data was compared to those of a second prototype with the same dimensions and equally instrumented, with ceramics roofing, under the same environmental conditions. The data comparison and analysis of specific days in each season, proved the green roof efficiency on retarding the building thermal gain. One expects that the results will encourage the application of green roofs, which will bring several advantages to the population.

Atualmente, as legislações ambientais e os consumidores estão cada vez mais exigentes e restritivos em relação ao adequado tratamento dado aos resíduos industriais. Neste contexto, a logística reversa tem por objetivo gerenciar os fluxos reversos, fazendo com que bens e produtos com pouco uso após a venda, com ciclo de vida útil ampliado ou após extinta a sua vida útil, retornem ao ciclo produtivo, readquirindo valor em outros mercados. Baseado em uma revisão bibliográfica, um estudo exploratório e um trabalho de campo, composto por entrevistas, analisa-se as possibilidades de aplicação do conceito de logística reversa na cadeia produtiva da Construção Civil, particularmente em relação aos fluxos de Resíduos de Construção e Demolição - RCD, como forma de contribuir para a sustentabilidade do ambiente construído. Expõe-se de forma ampla, os fatores intervenientes no processo de implantação dos sistemas logísticos reversos para RCD e os condicionantes e benefícios decorrentes desta aplicação, considerando os aspectos técnicos, econômicos e ambientas do reaproveitamento de RCD. A partir do estudo das práticas atuais de gerenciamento de RCD em empresas construtoras e de algumas experiências estrangeiras, conclui-se sobre as necessidades de avanço das práticas e legislações brasileiras relacionadas ao gerenciamento de RCD, e sobre o papel dos fornecedores no estabelecimento e consolidação de sistemas logísticos reversos - SLR. A aplicação do conceito é realizada na cadeia produtiva de Chapas de Gesso Acartonado - CGA, para a qual é proposto um sistema logístico reverso - SLR-CGA, englobando-se a caracterização dos agentes, as tecnologias de aproveitamento para resíduos de CGA e os mercados disponíveis para a sua reinserção, dentre outros pontos. São realizadas simulações de viabilidade econômica de possíveis cadeias reversas de CGA. A partir das alternativas viáveis, conclui-se sobre o efeito da implantação destas sobre a cadeia produtiva de CGA. Conclui-se que a implantação de um sistema logístico reverso consiste em uma ferramenta organizacional que pode ajudar companhias a resolver impactos econômicos e ambientais e criar novos negócios na cadeia produtiva da Construção Civil. / Currently, environmental legislation and pressure of consumer awareness are getting more stringent and restrictive in relation of the proper treatment gave to the industrial wastes. In this context, reverse logistics systems aims to manage the reverse flow, making with that facilities and products with little use after sales, useful life cycle extended or extinct, return to the productive cycle, to regain value still incorporated in them. Based on a bibliographical research and a survey, the possibilities of application of reverse logistics concept in Civil Construction productive chain is analyzed with focus on construction and demolition wastes (CDW).This analyze contribute for the sustainability in Civil Construction. The intervenient factors in the reverse logistics systems implementation is discussed, such as the benefits from the application, taking into account technical, economical e environmental aspects of recycling. The analyze of current CWD management system, mainly in building sites, avoids to conclude about Brazilian necessities and the important role that producers can have in this systems. The application of the concept is done in the drywall gypsum board supply chain. For this chain, a reverse logistics syste for gypsum board wastes (GBW) is proposed approaching the stakeholders, technologies of GBW and markets for recycled product, among another aspects. Economic liability simulations of possible GBW reverse chains are conduced and for that liable, the impact of its implementation is discussed. The implementation of reverse logistics systems is considered like an organizational tool that can help the companies to solve environmental and costs impacts on production and problems surroundings this issues.

Although rice straw and other grains have been used in building since pre-history, in the past two decades, there has been a move to utilize this rapidly renewable, locally available, agricultural byproduct as part of the sustainable construction movement. Up to this point, this has been done by simply stacking up the full straw bales. Stak Block, invented by Oryzatech, Inc., is a modular, interlocking block made of a composite of rice straw and binding agent that serves as an evolution in straw construction. This study investigates the feasibility of using these Stak Blocks as a structural system. The report was divided into four main parts: material testing, development of effective construction detailing, full-scale physical shear wall testing, and a comparison with wood framed shear walls. The first section investigated the feasibility of using the Stak Blocks in a load-bearing wall application. Constitutive properties of the composite straw material such as yield strength and elastic stiffness were determined and then compared to conventional straw bale. Next, the decision was made to prestress the walls to create a more effective structural system. Various construction detailing iterations were evaluated upon the full-scale shear wall testing using a pseudo-static cyclic loading protocol. Finally, the available ductility of the prestressed Stak Block walls in a lateral force resisting application is quantified along with an approximation of potential design shear forces. It was determined that the Stak Block material performed satisfactorily in gravity and lateral force resisting applications, in some respects better than conventional wood-framed construction, and has great potential as a seismically-resistant building material.