A reciclagem de resíduos constitui uma opção para amenizar o impacto ambiental resultante da quantidade expressiva de detritos gerados pelas atividades produtivas do segmento da construção. Deste modo, o objetivo deste estudo é avaliar a utilização de agregados graúdos reciclados de concreto (ARC) em substituição ao agregado graúdo natural (AGN) para a produção de concretos com resistência à compressão de 30 MPa. O programa experimental iniciou-se com a caracterização física e granulométrica do agregado graúdo reciclado de concreto (ARC), e posterior comparação com as propriedades do agregado graúdo natural (AGN). Com base no conhecimento dessas propriedades, deu-se início a etapa de produção dos concretos. Foram estudados diferentes procedimentos de forma a reduzir o efeito da absorção de água do concreto pelo agregado reciclado durante o estado fresco. Também foi avaliada a influência da utilização de diferentes teores (0, 10%, 20%, 50% e 100%) de substituição do agregado graúdo natural pelo agregado graúdo reciclado de concreto nas propriedades do estado fresco e do estado endurecido do concreto. Embora tenha se verificado uma redução nos valores de resistência em relação ao concreto de referência (sem a presença de ARC), os concretos alcançaram o valor especificado de resistência à compressão (30 MPa) para todas as porcentagens de substituição de AGN por ARC. Com relação às propriedades de módulo de elasticidade e resistência à tração por compressão diametral, verificou-se que a redução nos resultados se intensifica conforme aumenta a porcentagem de ARC incorporado à mistura. Os valores registrados para absorção de água, por sua vez, aumentavam gradativamente de forma proporcional à quantidade de ARC no concreto. / The recycling of waste is an option to minimize the environmental impact of the significant amount of waste generated by production activities in the construction segment. Thus, the aim of this study is to evaluate the use of recycled coarse aggregate concrete (ARC) to replace the natural coarse aggregate (AGN) for the production of concrete with compressive strength of 30 MPa. The experimental program began with physical and particle size characterization of the recycled coarse aggregate concrete (ARC), and for comparison with the properties of natural coarse aggregate (AGN). Based on the knowledge of these properties, the next step was the production of concrete. Different procedures to reduce the effect of absorption of water by recycled concrete aggregate at the fresh state were studied. Also it was evaluated the effect of using different amounts (0, 10%, 20%, 50% and 100%) replacement of the natural coarse aggregate for concrete recycled coarse aggregate in to the properties of concrete at the fresh state and at the hardened state. Although it has been verified a decrease in the compressive strength values in relation to the reference concrete (without the presence of ARC), for all AGN replacement percentages by ARC was reached the value specified compressive strength (30 MPa). With regard to the modulus of elasticity and splitting tensile strength, it was found that the reduction in results intensifies with increasing percentage of ARC incorporated into the mixture. The values recorded for water absorption, in turn, gradually increased in proportion to the amount of the ARC.

Uma das aplicações dos agregados provenientes da reciclagem dos resíduos de construção civil (ARC) é na fabricação de concretos no slump. Este tipo de concreto é utilizado na fabricação de peças conformadas por vibração e vibro compactação. Porém, as características dos agregados de ARC dificultam a dosagem desse tipo de concreto, pois ocorrem variações na trabalhabilidade dependendo da morfologia e absorção de água. O estudo da dosagem de ARC é importante pois ao ser utilizado altera as propriedades do concreto, em especial do concreto no slump, devido à necessidade de manter a forma imediatamente após a desmoldagem. Desta forma, o presente trabalho tem como objetivo avaliar o efeito do agregado ARC nas características do concreto no slump, com a avaliação da influência do processo de fabricação na forma das partículas e da pré-molhagem do agregado nas propriedades reológicas e na resistência mecânica à compressão. Para isto, foram estudadas composições de concretos utilizando agregados reciclados com diferentes teores de excesso de pasta e diferentes relações água/cimento (a/c), além da composição sugerida pela ABCP para concretos utilizados em meio fio com agregados naturais. Com a composição que apresentou os melhores resultados e com o traço de referência foi realizada a análise do custo de fabricação de uma peça de meio-fio com cada um dos concretos, a fim de se avaliar o impacto econômico da substituição do agregado. Observou-se diferenças entre os agregados reciclados e naturais, tanto em relação as propriedades quanto a morfologia, fatos que resultaram em características distintas também nos concretos obtidos. No estudo da pré-molhagem foi possível observar que diferentes taxas de pré-molhagem resultaram em comportamentos distintos tanto no estado fresco como no endurecido, sendo obtida variação de 60% na resistência à compressão entre os teores de 75 e 65% de pré-molhagem. Com a obtenção de traços variando o excesso de pasta e a/c pode-se observar que a composição com a/c de 0,35 e teor de pasta de - 5% foi a que resultou em melhores características para a produção de peças submetidas à vibração. Apesar desta composição atingir o mínimo de 11 MPa exigido por norma para a fabricação de meio-fio, o custo para fabricação de uma peça de concreto com agregado reciclado foi 17% maior do que o custo com agregados naturais, resultado ligado ao maior consumo de cimento exigido pelo concreto com ARC para atingir a resistência exigida. / One of the applications of aggregates from the recycling of civil construction waste (CCW) is in no slump concrete manufacturing. This type of concrete is used in the manufacture of parts shaped by vibration and vibrocompression, for example. However, the characteristics of CCW aggregates make it difficult to measure this type of concrete, since there are variations in the workability depending on the morphology and water absorption. The study of CCW aggregate is important because its use changes the concrete properties, especially in no slump concrete, due to the necessity to maintain the form immediately after the demolding. Therefore, the present work aim to evaluate the effect of the CCW aggregate on the no slump concrete characteristics, with the evaluation of the influence of the particle formation process and the pre-wetting of the aggregate on the rheological properties and the compression strength. For this, concrete compositions were studied using recycled aggregates with different contents of excess paste and different water/cement (a/c) ratios, in addition to the composition suggested by ABCP for concrete used in curb with natural aggregates. With the composition that presented the best results and with the reference mix design it was performed the analysis of the manufacturing cost of a piece of curb with each of the concretes, in order to evaluate the economic impact of the replacement of the aggregate. It was observed differences between the recycled and natural aggregates, both in relation to the properties and morphology, facts that resulted in different characteristics also in the concretes obtained. In the pre-wetting study, it was possible to observe that different pre-wetting rates resulted in different behaviors in both the fresh and hardened state, with a 60% variation in the compressive strength between 75 and 65% pre-wetting rates. By obtaining traces varying the excess of paste and a/c it can be observed that the composition with a/c of 0.35 and paste content of -5% was the one that resulted in better characteristics for the production of vibration pieces. Although this composition reached the minimum of 11 MPa required by standard for the production of curb, the cost for manufacturing a piece of concrete with recycled aggregate was 17% higher than the cost with natural aggregates, a result linked to the higher consumption of cement required by concrete with CCW to achieve the required strength.

A reciclagem de resíduos constitui uma opção para amenizar o impacto ambiental resultante da quantidade expressiva de detritos gerados pelas atividades produtivas do segmento da construção. Deste modo, o objetivo deste estudo é avaliar a utilização de agregados graúdos reciclados de concreto (ARC) em substituição ao agregado graúdo natural (AGN) para a produção de concretos com resistência à compressão de 30 MPa. O programa experimental iniciou-se com a caracterização física e granulométrica do agregado graúdo reciclado de concreto (ARC), e posterior comparação com as propriedades do agregado graúdo natural (AGN). Com base no conhecimento dessas propriedades, deu-se início a etapa de produção dos concretos. Foram estudados diferentes procedimentos de forma a reduzir o efeito da absorção de água do concreto pelo agregado reciclado durante o estado fresco. Também foi avaliada a influência da utilização de diferentes teores (0, 10%, 20%, 50% e 100%) de substituição do agregado graúdo natural pelo agregado graúdo reciclado de concreto nas propriedades do estado fresco e do estado endurecido do concreto. Embora tenha se verificado uma redução nos valores de resistência em relação ao concreto de referência (sem a presença de ARC), os concretos alcançaram o valor especificado de resistência à compressão (30 MPa) para todas as porcentagens de substituição de AGN por ARC. Com relação às propriedades de módulo de elasticidade e resistência à tração por compressão diametral, verificou-se que a redução nos resultados se intensifica conforme aumenta a porcentagem de ARC incorporado à mistura. Os valores registrados para absorção de água, por sua vez, aumentavam gradativamente de forma proporcional à quantidade de ARC no concreto. / The recycling of waste is an option to minimize the environmental impact of the significant amount of waste generated by production activities in the construction segment. Thus, the aim of this study is to evaluate the use of recycled coarse aggregate concrete (ARC) to replace the natural coarse aggregate (AGN) for the production of concrete with compressive strength of 30 MPa. The experimental program began with physical and particle size characterization of the recycled coarse aggregate concrete (ARC), and for comparison with the properties of natural coarse aggregate (AGN). Based on the knowledge of these properties, the next step was the production of concrete. Different procedures to reduce the effect of absorption of water by recycled concrete aggregate at the fresh state were studied. Also it was evaluated the effect of using different amounts (0, 10%, 20%, 50% and 100%) replacement of the natural coarse aggregate for concrete recycled coarse aggregate in to the properties of concrete at the fresh state and at the hardened state. Although it has been verified a decrease in the compressive strength values in relation to the reference concrete (without the presence of ARC), for all AGN replacement percentages by ARC was reached the value specified compressive strength (30 MPa). With regard to the modulus of elasticity and splitting tensile strength, it was found that the reduction in results intensifies with increasing percentage of ARC incorporated into the mixture. The values recorded for water absorption, in turn, gradually increased in proportion to the amount of the ARC.

Made available in DSpace on 2017-06-01T17:57:24Z (GMT). No. of bitstreams: 1 dissertacao_wellington_amorim.pdf: 3048381 bytes, checksum: 333317e062126e6f626919d08764c6a7 (MD5) Previous issue date: 2008-12-01 / It was accomplished in the Metropolitan Area of Recife in the municipal districts of Abreu e Lima, Araçoiaba, Cabo de Santo Agostinho, Camaragibe, Igarassu, Ipojuca, Itamaracá, Itapissuma, Moreno, Olinda, Recife, Jaboatão dos Guararapes and São Lourenço da Mata the collection of materials that they serve as Clay-Shale, in lied explored already commercially, with the objective of evaluating the best characteristic of that Clay-Shale and the application in mortars in the building site, as well as his/her way use no more empiric. For that it was made right the rehearsals of physical characterization through the analysis granulométrica with sedimentation in agreement with ABNT-NBR 7181/1984, the consistence (liquidity limit according to ABNT-NBR 6459/1984 and plasticity limit according to ABNT-NBR 7180/1984). The determination of the specific mass of the grains of the soil in agreement with ABNT-NBR 6508/1984, contraction limit in agreement with ABNT-NBR 7183/1982. The obtained results indicate that significant influence exists in the amount of clay and in the contraction degree. / Foi realizado na Região Metropolitana do Recife nos municípios de Abreu e lima, Araçoiaba, Cabo de Santo Agostinho, Camaragibe, Igarassu, Ipojuca, Itamaracá, Itapissuma, Moreno, Olinda, Recife, Jaboatão dos Guararapes e São Lourenço da Mata a coleta de materiais que servem como Saibro, em jazidas já exploradas comercialmente, com o objetivo de avaliar a melhor característica desse Saibro e a aplicação em argamassas na construção civil, bem como o seu uso de modo não mais empírico. Para isso se fez jus os ensaios de caracterização física através da análise granulométrica com sedimentação de acordo com a ABNT-NBR 7181/1984, a consistência (limite de liquidez conforme ABNT-NBR 6459/1984 e limite de plasticidade conforme ABNT-NBR 7180/1984). A determinação da massa específica dos grãos do solo de acordo com a ABNT-NBR 6508/1984, limite de contração de acordo com a ABNT-NBR 7183/1982. Os resultados obtidos indicam que existe influência significativa na quantidade de argila e no grau de contração.

The theme of the diploma thesis is the study of physical properties of various building materials in buildings in low-energy construction. The work is mainly focused on the influence of the thermal accumulation properties of building materials used in buildings in order to achieve low energy consumption for heating. The thesis compares the energy characteristics of five different constructional material variants of the house.

This thesis examines the possibility of passive house standard construction of public buildings in the countryside of the Czech Republic, the possibility of application of natural materials in their construction and in the end set of architectural principles for their design. Examines the situation of expansion of this type of buildings in the surrounding countries as well as in our country, differences in their architectural and technical characteristics and possibilities of natural materials use in their construction so that the newly proposed public buildings meet not only the technical and architectural design principles of passive houses, but at the same time reflect using of traditional local natural materials.

Die weltweite Veränderung der klimatischen Bedingungen macht eine deutliche Verringerung des globalen Ausstoßes von Treibhausgasen unumgänglich. Der Bausektor und insbesondere die Zementherstellung sind von diesen Entwicklungen nicht ausgenommen, weshalb die Suche nach alternativen, nachhaltigen Baumaterialien verstärkt in den Fokus der Industrie und der Wissenschaft rückt. Im vorliegenden Artikel sollen einige Entwicklungstendenzen aufgezeigt und gewisse Potentiale und besondere Eigenschaften dieser Materialien hervorgehoben werden. Dabei erheben die Autoren mit diesem Aufsatz keinesfalls den Anspruch auf eine vollständige Darstellung aller bekannten Optionen, sondern er soll vielmehr zu neuen Denkansätzen motivieren und Forschungsbedarf aufzeigen.

Construction activity is known to have a major impact on the environment and is a major consumer of a wide range of naturally occurring and synthesized resources. Despite the recognition that environmental issues are important to the survival of the construction industry, the industry continues to degrade the environment, exploiting resources and generating waste, and is slow to change its conventional practices to incorporate environmental matters as part of its decision making process. With increased awareness and knowledge of these impacts, efforts are being made to avoid these adverse effects and to work towards impact mitigation. Among these is sustainable building material selection. Building material selection is an important issue in building design and construction decision-making and environmental issues need to be incorporated into the evaluation process. The research reported in this thesis was initiated to address these issues in the UK, towards developing an assessment model for incorporating sustainability into building material selection process. A questionnaire survey was conducted to investigate the level of awareness, knowledge and implementation of sustainable practices among architects and designers and how this impacts on their design decisions. To facilitate the implementation of sustainable practices into building material selection, a set of sustainable assessment criteria (SAC) for modeling and evaluating sustainability performance of building materials was developed. Building material can be assessed using an index system that combines the principal criteria of sustainable development. The derived criteria were assessed and aggregated into a composite sustainability index using the Analytical Hierarchy Process (AHP) technique which has been praised for its ability to incorporate both objective and subjective considerations in the decision process. The development of a sustainability index is a way of supporting decision makers faced with making numerous and sometimes conflicting evaluation as with building material selection. The methodology adopted in undertaking this research was the mixed method approach involving a detailed review of the relevant literature, followed by an industry-wide survey of UK architects and designers. Following this, case study was conducted to collect data for sustainability criteria used in the assessment model. The data collected were analyzed, with the aid of SPSS, Excel and expert choice software using a variety of statistical methods including descriptive statistics analysis, relative index analysis, Kendall’s concordance and factor analysis. The key finding was the existing gap between awareness and implementation of sustainable construction practices, which has led to failure of realizing the benefits of a sustainable approach to construction. The study showed a discrepancy between what architects and designers claim to be convinced about, and knowledgeable in, and their commitment and practices; they seem to be unable to translate their environmental awareness and knowledge into appropriate design decisions and are in need of a decision support system that can aid the incorporation of sustainability into building design. The model developed satisfy this gap and was validated by application to a roof covering material selection decision process for a case study building project by means of experts’ review via a survey and the findings obtained suggest that the model is valuable and suitable for use in practice. Finally, areas for further research were identified.

A reciclagem de resíduos tem sido tema de diversos estudos e pesquisas, já que o meio ambiente vem sofrendo muitos impactos ambientais por conta do desenvolvimento da indústria mundial. Nessa linha, muitas empresas têm adotado estratégias mercadológicas ditas sustentáveis, procurando atender a um requisito que, atualmente, interessa a toda a sociedade: desenvolvimento sustentável. E uma das maneiras de haver desenvolvimento econômico sustentável, minimizando os impactos ao meio ambiente, é utilizar os resíduos gerados aplicandoos em outros processos de produção. Sendo assim, o presente trabalho propõe utilizar a cinza, que resulta da queima do carvão mineral adicionado ao calcário dolomítico e a areia, gerada pelo reator de leito fluidizado circulante de uma indústria produtora de alumínio localizada na área industrial de São Luís do Maranhão. O objetivo deste trabalho é avaliar a melhor utilização desse resíduo sólido industrial em matrizes cimentícias. A investigação experimental inicia com a classificação e caracterização do resíduo in natura, avaliando seu potencial pozolânico. Com os resultados dos ensaios foi possível indicar que o seu melhor uso é como agregado, devido sua característica de não pozolânico. Também, devido a sua composição granulométrica de característica mais fina e sua elevada superfície específica, propõese que a cinza seja adicionado como filler. A etapa seguinte compreende a produção de matrizes compostas de cimento, areia e cinza (utilizada como filler), nessa etapa foram testados vários traços, aferindo suas propriedades mecânicas e eficiência de estabilização da matriz. O traço que melhor respondeu a essas questões foi o 1 : 1,5 : 1,5 (cimento:areia:cinza), pois apresentou bom desempenho mecânico utilizando grande quantidade de resíduo. Definida a matriz, essa foi submetida a ensaios complementares, para então ser aplicada na produção dos blocos prensados. Os blocos apresentaram bom desempenho mecânico e físico. A eficiência da estabilização do resíduo na matriz apresentou bons índices nos extratos solubilizados e até 100% de estabilização por solidificação, porém alguns parâmetros ainda apresentaram resultado acima do estabelecido por norma. Concluise então, que os blocos de cinza volante podem ser utilizados na construção civil, desde que sejam seguidas algumas recomendações quanto a produção e utilização dos mesmos. / The recycling of waste has been the subject of several studies and research, since the environment has undergone many environmental impacts due to the development of the industry worldwide. For that reason, many companies have adopted socalled sustainable marketing strategies, trying to meet a requirement that currently involves the whole society: the sustainable development. And one way to achieve sustainable economic development while minimizing impacts on the environment is the use of generated waste by applying it to different production processes. Therefore, this research proposes the use of ash from burning coal added to the lime and sand, generated by circulating fluidized bed reactor of an industry that produces aluminum located in the industrial area of São Luís, Maranhão. The aim of this study is to evaluate the best use of industrial solid waste in cementitious matrices. The experimental investigation starts with the classification and characterization of the waste in nature, evaluating its pozzolanic potential. From the test results it was possible to indicate that its best use is as an aggregate, due to its nonpozzolanic characteristic. Also, due to its small granulometry and high specific surface, it is proposed the ash to be added as a filler. The next step involves the production of matrices composed by cement, sand and ash (used as filler). At this stage various compositions were tested, assessing their mechanical properties and efficiency on the matrix stabilization. The composition that better responded to these questions was 1: 1.5: 1.5 (cement: sand: ash), once it showed good mechanical performance using large amounts of waste. This matrix was subjected to further testing and was subsequently used to produce the compressed blocks. The blocks showed good mechanical and physical performance. The efficiency of waste stabilization in the matrix showed good levels in solubilized extracts and up to 100% stabilization by solidification, but some parameters still showed results above the established by the norm. We conclude that the blocks made using fly ash can be used in construction, since some recommendations regarding their production and use are followed.

Long term durability is a major concern for wide-scale use of recycled aggregate materials in civil engineering construction. The purpose of this study is to provide an insight into the damaging effects of combined wet-dry cycles and repeated mechanical loading in a recycled aggregate concrete (RAC) base course material made from recycled crushed concrete aggregate and cement. A coordinated experimental program followed by a mechanistic pavement modeling and life cycle analysis was conducted as part of this research study. This laboratory investigation was divided into three phases each consisting of both wet-dry exposed specimens (WD), and control or non wet-dry exposed specimens (NWD). Phase I experiments involved monotonic loading tests under compression and flexure to evaluate the strength properties. Phase II involved testing a total of 108 cylindrical specimens in cyclic compressive loading at three different stress ratios. After each regime of cyclic loading, residual compressive strengths were determined. In addition, the load-deformation hysteresis loops and the accumulated plastic deformation were continuously monitored through all loading cycles. Phase III included a flexural fatigue test program on 39 beam specimens, and fracture testing program on 6 notched beam specimens, each one having 19-mm initial notch. Traditional SR-N curves, relating the Stress Ratio (SR) with the number of cycles to failure (N or Nf), were developed. Fatigue crack growth rate and changes in Stress Intensity Factors were obtained to determine Paris Law constants and fracture toughness. A mechanistic analysis of a typical highway pavement incorporating RAC base was performed with KENPAVE program, followed by a Life Cycle Analysis (LCA) using the GaBi software. It was found that the specimens subjected to wet-dry cycles suffered significantly higher damage expressed in terms of accumulated plastic deformation, and loss of residual compressive strength, modulus, fatigue endurance limit, and design life, compared to specimens not exposed to wet-dry cycles. Although such degradation in material properties are important considerations in pavement design, a concurrent Life Cycle Analysis demonstrated that recycled aggregate concrete base course still holds promise as an alternative construction material from environmental stand point. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection