Reuse is a measure for resource-saving materials and energy use, which is stressed in the concept of kretsloppsanpassning, or societal industrial ecology (SIE), as it will be termed in this thesis. Reuse is here used as a general term for any kind of reuse and divided into recirculation, upgrading and cascading, according to the degradation of the inner material structure. Reuse of construction materials in society is mainly done with the belief that any kind of reuse is environmentally beneficial. However, this assumption is seldom critically assessed. The aim of this thesis was to examine under which conditions reuse of construction materials in the Swedish building and transportation sectors is beneficial to the environment. In order to identify critical conditions, the environmental performance of actual building projects that to a large extent utilised reused building materials was assessed (Papers V-VI). To better understand the practice of SIE and how it was implemented, the transportation sector was studied (Paper I). In order to address the issue of assessing the environmental performance of construction material reuse, method development became an important part of this thesis. Methods and tools employed in this thesis were required to be able to simultaneously address different system boundaries and also involve simplification. Studying the implementation of SIE revealed the lack of a holistic approach in environmental management, though it is present in the overall objectives of the SIE concept (Paper I). This was concluded by studying the energy and material stocks and flows in a life-cycle perspective in the environmental management of the Swedish National Rail and Road administrations. The study showed that the SIE-related measures implemented were outflow oriented, while the material inflows were generally quantified. Overall, the management and use phases were addressed, while the construction and deconstruction phases were poorly considered. Studying environmental assessment methods showed that an important characteristic is the system boundaries, which to a large extent decide which issues could be addressed and what actually could be studied (Paper II). Environmental assessment methods applied to reuse of construction materials were organised in an assessment framework of four system levels: the material level, the local environment level, the narrow life-cycle level and the industrial system level. It was concluded that mainstream environmental assessment of construction material reuse that is performed in the process of development consent and also in research, mainly addresses the narrow scope of the material level. In order to apply a holistic approach to environmental assessments of reuse of construction materials, the system boundaries needed to be widened. When selecting system boundaries, methods and indicators, researchers indirectly decide on which environmental pressures we consider the most important (cf. Papers II - III). There are trade-offs between making broad or deep environmental assessments. To accomplish an environmental assessment wide in its scope requires abundant resources and is complicated to carry through. Simplifications of the complex reality are always needed. However, to counteract the risk of problem shifting, the simplified methods and indicators need to be balanced for environmental relevance and used with knowledge of what they reflect and what is left out (Paper III). One example of such method simultaneously environmentally relevant and capable to cope with wide system boundaries is the study of primary energy use in a life cycle perspective, applied to a material an energy use context (see Papers IV-VI). In searching for a tool to prioritise building materials in building research and environmental management of the building sector, the total amount of building materials present in the Swedish building material stock was multiplied by their embodied energy coefficients (Paper IV). This product was normalized for the building materials’ service life. The accounting resulted in an ordering of building material categories according to their energy intensity. These are, in decreasing order: wood materials, bricks and other ceramics, concrete and steel. After calculating energy use in a life-cycle perspective for the recirculation, upgrading and cascading of larger building reuse projects of concrete and clay bricks, it is not self-evident that reuse is beneficial for the environment (Paper V, VI). It mainly depends on the use of auxiliary materials and their embodied energy, but also the primary energy use for the reuse processes, such as transportation distance and mode between the deconstruction and construction sites. In order to improve the environmental benefits of reuse, primarily the auxiliary materials used in current reuse projects should be minimised. Otherwise, there is a risk that the energy use for these materials turns reuse into an unfavourable process for the environment. Furthermore, reuse should preferably be environmentally assessed with a wide scope before implementation. What is included in such environmental assessment is significant for the outcome and the pictured environmental performance. / On the day of the public defence of the doctoral thesis the status of article III was: Accepted.

This exam report has been developed in association with Strangbetong AB, Sweden. The natural gravel that is being used as fine aggregate for concrete production today is an ending natural recourse and the Swedish government has decided to strongly reduce the extraction from the year of 2020. The only reasonable replacement is aggregates from crushed rocks but this material has other properties than natural aggregates. The concrete manufacturers now have to learn how to use these new fine aggregates in a cost effective way in order to ensure the quality of their concrete production. In this project, crushed aggregates and combination of crushed and natural aggregates have been tested with existing formulas for fresh concrete. The two parameters yield stress and plastic viscosity have been measured which gives a good description of the workability of the fresh concrete. Different methods to make measurements on the dry fine aggregates, has also been tested, to find out if there is any correlations between these parameters and the parameters from the measurement on the fresh concrete.

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2004. / Includes bibliographical references (p. 173-174).

Diss. Uppsala : Sveriges lantbruksuniv., 2004.

Diss. (sammanfattning) Umeå : Univ., 2006. / Härtill 5 uppsatser.

No description available.

Orientador: Luísa Andréia Gachet Barbosa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-24T15:19:21Z (GMT). No. of bitstreams: 1 Santos_VaniaReginaFerreirados_M.pdf: 1698251 bytes, checksum: acb74baaabcae217648c5433fbcfcde1 (MD5) Previous issue date: 2014 / Resumo: As questões de acessibilidade reduzem as desigualdades e promovem a inclusão social. Embora, no Brasil, nas últimas décadas as políticas públicas relacionadas à mobilidade urbana vem sendo incrementadas para assegurar a todos o direito constitucional de ir e vir, a realidade apontada no Censo Demográfico de 2010 do Instituto Brasileiro de Geografia e Estatística ¿ IBGE sobre população residente por tipo de deficiência, enfatiza a importância da atenção à questão da acessibilidade e de assegurar os direitos das pessoas com deficiência. Com a crescente demanda de execução de calçadas com padrões de acessibilidade, levantou-se a problemática da escassez de estudos sobre a dosagem quando pretende-se produzir pisos táteis intertravados de concreto com fibras de aço, utilizando o Resíduo de Construção Civil ¿ RCC reciclado como matéria prima visando uma solução ambiental adequada para a disposição final desses RCC, contribuindo ainda, para a preservação dos recursos naturais. Frente ao exposto, com o intuito de colaborar com o meio técnico na resolução desses problemas e auxiliar na minimização do impacto ambiental causado pela extração do agregado natural e disposição irregular dos RCC e ainda fornecer maior autonomia e qualidade de vida da pessoa com deficiência visual, esta pesquisa tem como principal objetivo produzir pisos táteis intertravados de concretos com fibras de aço substituindo em massa porcentagens de agregados miúdos naturais por reciclados. Inicialmente foram selecionados os materiais e realizada a caracterização, e posteriormente, feito uma pesquisa bibliográfica para escolher um traço de partida para a produção dos pisos. Foram realizados alguns ensaios experimentais para adequá-lo, uma vez que foi adicionado fibras e também realizado um estudo para a relação água/cimento, devido a substituição do agregado natural pelo reciclado de cor cinza. Foram moldados pisos táteis, corpos-de-prova prismáticos e placas de concreto, com cinco traços, o primeiro utilizado como concreto de referência com fibras de aço e os demais com adição de RCC nas proporções de 15%, 20%, 25% e 50%. Foram analisadas as propriedades: resistência à compressão, absorção de água, resistência à abrasão, tenacidade e resistência à tração e feitas comparações do resultado obtido com de outros autores nacionais e internacionais e com as normas da Associação Brasileira de Normas Técnicas ¿ABNT. Os resultados encontrados comprovam a viabilidade de produzir pisos táteis de concreto com fibras de aço utilizando RCC / Abstract: Accessibility matters reduce inequalities and promote social inclusion. Although, over the last decades, public policies related to urban mobility have been implemented in Brazil to ensure to everybody the constitutional right of coming and going, The reality according to the demographic census of 2010 of Brazilian Institute of Geography and Statistics ¿ IBGE about the residents for type of disability, points up the importance of providing accessibility and ensuring the rights of disabled people. The demand for this kind of paving increases to be used in sidewalks with accessibility standards, the problem of lack of studies about dosage for the production of interlocked steel fiber floors raises, using recycled Construction Waste as raw material. The production would provide an appropriate environmental solution for the final disposal of Construction Waste, contributing for the preservation of natural resources. In view of this, aiming to collaborate with the technical area in solving these problems, assist in minimizing the environmental impact caused by the extraction of the natural aggregate and irregular Construction Waste disposal and offer more autonomy and quality of life to the visual impaired person, this research main objective is to produce interlocked floors made of concrete and steel fiber replacing in mass percentages small natural aggregates to recycled aggregates. First it was selected the materials and performed characterization tests. Later a review of the literature was performed to choose a starting trait for the paving production. We also had experimental tests for adjusting it since we had added fiber to it and a study was made to determine the relation between water/cement due to the replacement of the natural aggregate to the grey recycled one. Some tactile floors, prismatic sample parts and concrete plaques were molded with 5 traces: the first used as concrete reference with steel fibers and the others with addition of Civil Construction Waste in the following proportions: 15%, 20%, 25% and 50% in mass replacement. It was then analyzed the properties: resistance compression, water absorption, abrasion, tearing and traction. It was made comparisons between this work and other national and international authors and with the ABNT standards - Associação Brasileira de Normas Técnicas and the findings proved the viability in producing tactile concrete and steel fibers floors using Civil Construction Waste / Mestrado / Tecnologia e Inovação / Mestra em Tecnologia

Moisture is one of the primary factors connected with the damage observed on the envelope of buildings. The moisture states are normally dominated by moisture transport processes within and between porous building materials from rain penetration, rising damp or infiltration of water vapour that is normally accompanied with heat transfer. The research into moisture transport behaviour of building materials is extremely important for the characterisation of behaviour in connection with durability, waterproofing, degradation of appearance and thermal performance ofbuilding elements. In the first stage of this research, commercial gypsum plasters were experimentally investigated with their moisture transport specifications. The hydraulic parameters including sorptivity, saturated conductivity and permeability of water vapour were determined with new findings related with the dependence of hydraulic parameters on water/plaster ratios, wetting-drying cycles and additives. The results obtained were compared with other porous building materials and recommendations for their manufacture and selection in building construction were made. Secondly, on the basis of comprehensive investigations of the dielectric properties of gypsum plasters, an integrated automatic real-time monitoring system for moisture transport processes was designed and successfully developed utilising a pin-type resistance sensor and sensor array. The data acquisition, data analysis, result display and saving are all integrated with the computer controlled interface. The polarisation effects and temperature effects for various gypsum plaster materials were compensated and realised by control options. The monitoring system developed for moisture monitoring was directly applied in 1-dimension moisture transport processes and can easily be extended to the monitoring of 2 or 3 dimension moisture transport processes by embedding an appropriate sensor array into materials. In the third part of the research, on the basis of experimental investigation of water absorption processes of uniform materials and two-layer composites, the water diffusivity as functions of moisture content were determined from experimental moisture profiles for various gypsum plaster materials. The models governing the moisture transport processes were formed based on extended Darcy's law and experimental diffusivity functions. By applying the finite element method and developed software, the non-linear partial differential equations were numerically solved under specified boundary and initial conditions in absorption processes. The simulation results achieved satisfactory agreement with experimental moisture profiles for various materials and for two-layered composites.

Issues concerning mechanisms of durability of hydrated cement phases in aggressive environments were studied. The possibility of using organic compounds in order to modify the micro- and nanostructure of the calcium-silicate-hydrate (C-S-H) phases was also investigated. Pure cement-based hydrated phases were synthesized and characterized by several analytical techniques such as X-ray diffraction, thermal gravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Compacted samples of the synthetic hydrated cement phases were also prepared and used for the assessment of durability and mechanical properties. This doctoral thesis is comprised of several research chapters which can be categorized into two main parts. The first part focuses on the development of novel organically modified C-S-H systems. The second part involves the mechanisms underlying the volume stability of phase pure sulfoaluminate and related phases. A brief description of each part is as follows: - development of novel organically modified C-S-H systems: The mechanisms of interaction of organic compounds with the nanostructure of C-S-H systems were studied. A model for the nanostructure of the resulting composite systems was proposed. In addition, the organically modified systems were tested for length-change, calcium-ion leaching and diffusion of isopropanol. Dynamic mechanical analysis and microindentation techniques were also used to determine the mechanical performance. Evidence of the superior engineering performance of the novel organically modified C S-H systems was provided. - mechanisms of the volume stability of sulfoaluminate and related phases: Volume stability and change in the microstructure of the synthetic ettringite, monosulfate and thaumasite was critically examined in de-ionized water as well as in highly concentrated gypsum- or lime-water. A new dissolution-based mechanism for the expansion of these phases was proposed. The volume stability of multicomponent systems comprised of the C-S-H-based system (prepared in part I) and these sulfate-based hydrated phases was also investigated. It was suggested that the systems containing the modified C-S-H rather than the phase pure C-S-H had better resistance to crack growth and disintegration originating from the presence of ettringite or thaumasite.

Debido al deterioro que presentan actualmente los pavimentos y la gran brecha de la infraestructura vial en el Perú, de aproximadamente 24 mil km, la tecnología debe lograr que las nuevas redes de infraestructura vial respondan eficientemente a construcciones sostenibles con la incorporación de residuos de la industria, para mitigar los impactos ambientales que generan. En el Perú, cada día se generan residuos de caucho por el desecho de llantas y el aumento del parque automotriz, generando un impacto ambiental negativo. Estos residuos, tienen el gran potencial de ser una fuente reutilizable con la finalidad de ser incorporados sobre mezclas a base de cemento, reduciendo el impacto medioambiental, la huella de carbono y constribuyendo a la ejecución de pavimentos eco-sostenibles. En esta investigación, se estudió el comportamiento de 11 muestras de concreto utilizando caucho reciclado de tamaños de 20 y 25 mm, para reemplazar hasta un 50% del agregado fino del concreto. El diseño de mezcla contiene los parámetros de diseño para pavimentos urbanos de concreto, utilizando aditivos reductores de agua y de fragua. Los resultados de las pruebas indicaron que las muestras con incoporación de caucho, son resistentes a la compresión hasta reemplazos del 20%. Se obtuvo el módulo de rotura mínimo de 36 kg/cm2 con reemplazos hasta de 40%. La mezcla optimizada obtuvo una reducción en el costo de fabricación por metro cúbico de 2.9% y una reducción de la huella de carbono de 0,4%. / Must to the deterioration that pavements currently present and the large hole in road infrastructure in Peru, of approximately 24 thousand kilometers, technology must achieve that the new road infrastructure in the country respond efficiently to sustainable constructions with the incorporation of waste of industry, to mitigate the environmental impacts that generate. In Peru, every day rubber waste is generated by the waste of disused tires and the increase of the automobile park, generating a negative environmental impact. These wastes have the great potential of being a reuse source with the purpose of be incorporated on cement-based mixtures, reducing the environmental impact, the carbon footprint and contributing to the realization of eco-sustainable pavements. In this investigation, was studied the behavior of 11 concrete samples using recycled rubber of 20 and 25 mm sizes, to replace until 50% of the fine concrete aggregate. The mix design contains the design parameters for urban concrete pavements, using water reducer and retarder admixtures. The results of the tests indicated that the samples with rubber incoporation, in both sizes, are resistant to compression until to 20% replacements. The minimum modulus of rupture obtained was 36 kg/cm2 with replacements until to 40% of rubber replacement. The optimized mixture obtained a reduction in manufacturing cost per cubic meter of 2.9% and a carbon footprint reduction of 0.4%. / Tesis