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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Properties of geopolymers sourced from construction and demolition waste: A review

Alhawat, Musab M., Ashour, Ashraf, Yildirim, Gurkan, Sahmaran, M. 13 April 2022 (has links)
Yes / Geopolymers have been recognised as a viable replacement to ordinary Portland cement (OPC), providing a cleaner solution since it can significantly reduce greenhouse gas emissions as well as accomplishing effective waste recycling. Construction and demolition waste (CDW) has been recently identified as raw materials for geopolymers due to its availability and high contents of silica and alumina. This paper aimed at reviewing the current state-of-the-art on the geopolymer paste, mortar, and concrete production and their properties, with special attention paid to geopolymers incorporating CDWs. The review covers brief assessment of using CDWs in concrete, the mix design of geopolymer mixtures in addition to identification of the main factors influencing the performance of geopolymer containing CDW. The most recent data related to the mechanical and durability properties of CDW-based geopolymers are presented, while the cost and environmental impacts of using recycled materials in producing geopolymer concretes are also discussed. Geopolymer concretes have a vast range of possible applications, however, there are still several barriers facing commercialisation of geopolymers in construction industry. The review indicated that it is possible to produce geopolymer concretes from CDW-based materials with properties comparable to OPC-based ones; however, the selection of proper material composition should be carefully considered, especially under normal curing conditions.
42

Structural performance of construction and demolition waste-based geopolymer concrete columns under combined axial and lateral cyclic loading

Akduman, S., Aktepe, R., Aldemir, A., Ozcelikci, E., Yildirim, Gurkan, Sahmaran, M., Ashour, Ashraf 09 October 2023 (has links)
Yes / Construction and demolition waste (CDW) has reached severe environmental and economic dimensions due to its large volume among all solid waste, highlighting the importance of local actions to manage, recycle, and reuse CDW. Ductile demountable connections are necessary to disassemble and reuse the concrete structural members and fast assembly of precast structures in seismic regions without generating waste. In this study, the seismic performance of CDW-based reinforced geopolymer concrete columns has been investigated. Six ½ scaled columns (half of which were demountable and the other half monolithic) were experimentally tested under reversed cyclic lateral displacement excursions, considering three different levels of constant axial loading to determine failure mechanisms, load–displacement responses, ductilities, energy dissipation capacities, stiffness degradation relations, and curvature distributions. The obtained test results were used to determine the performance of CDWbased geopolymer concrete columns and compare the performances of the demountable connection with the monolithic connection. The test results showed that the novel demountable connection for precast concrete frames exhibited better seismic performance in terms of maximum lateral load capacity, initial stiffness, energy dissipation capacity, and maximum curvature than their monolithic counterparts. Besides, increasing the axial compression ratio on the columns caused an increase in lateral load capacity, energy dissipation capacity, energy dissipation ratio, and initial curvature stiffness; however, it decreased the ductility. Finally, the capacity predictions of current codes, i.e., TS500 and ACI318, were conservative when compared with experimental results. / This publication is a part of doctoral dissertation work by the first author in the Academic Program of Civil Engineering, Institute of Science, Hacettepe University. The authors gratefully acknowledge the financial assistance of the European Union’s Horizon 2020 research and innovation program under grant agreement No: 869336, ICEBERG (Innovative Circular Economy Based solutions demonstrating the Efficient recovery of valuable material Resources from the Generation of representative End-of-Life building material). This work was also supported by Newton Prize 2020. The fifth and seventh authors acknowledge the financial support received from the European Union’s Horizon 2020 research and innovation program under the Marie SkłodowskaCurie grant agreement No 894100. / The full-text of this article will be released for public view at the end of the publisher embargo on 4th Oct 2024.
43

An Investigation into Durability Aspects of Geopolymer Concretes Based Fully on Construction and Demolition Waste

Ozcelikci, E., Yildirim, Gurkan, Alhawat, Musab M., Ashour, Ashraf, Sahmaran, M. 30 March 2023 (has links)
Yes / The focus of the construction industry has shifted towards the development of al-ternative, eco-friendly and green construction materials due to the energy-inefficient and carbon-intensive nature of Portland cement (PC) production and aggregate quarrying. Meanwhile, increased number of repetitive re-pair/renovation/maintenance activities and demolition operations for the end-of-life buildings generate significant amounts of construction and demolition waste (CDW). For the purposes of sustainability and upcycling wastes into high-value-added materials with improved greenness, components from CDW streams can be used in producing geopolymer concretes without using PC and natural aggre-gates, given the rich aluminosiliceous nature of CDW components. The focus of current work is therefore on the analysis of durability of aspects (i.e., drying shrinkage and resistance against sulfate attack, cyclic freezing-thawing, and chlo-ride penetration) of geopolymer concretes made entirely of CDW. Different types of bricks, tile, concrete, and glass were used in mixed form as precursors for ge-opolymerization while different-size grains of waste concrete were used as recy-cled aggregates. As alkali activators, sodium hydroxide, calcium hydroxide and sodium silicate were used. In a companion mixture, CDW-based precursors were replaced with slag and class-F fly ash. Results showed that sulfate and cyclic freeze-thaw exposure did not cause any noticeable weight and compressive strength loss in CDW-based geopolymer concretes, while chloride penetration was found comparable to PC-based concrete. While drying shrinkage was found high in entirely CDW-based geopolymer concrete and resulted in surface mi-crocracks, it was possible to lower the drying shrinkage substantially via substi-tution of CDW-based precursors with fly ash and slag. / The authors also wish to thank the support of Scientific and Technical Research Council (TUBITAK) of Turkey provided under projects: 218M102 and 117M447. / This paper is from the fib Symposium 2023, Building for the future: Durable, Sustainable, Resilient. 5-7 Jun, Istanbul, Turkey.
44

Challenges and Opportunities of Reusing Materials in Construction (Sweden) : A PEST-SWOT Analysis

Inanloo, Peyman January 2024 (has links)
This thesis explores the challenges and opportunities of reusing construction and demolition waste within Sweden's construction sector, employing a PEST-SWOT analytical framework. The focus is on three primary materials prevalent in residential single-family houses: brick, concrete, and timber. The study identifies key political, economic, social, and technological factors that influence material reuse practices. The analysis highlights substantial barriers including regulatory complexities, lack of incentives, and the tendency to often prioritize new over reused materials due to perceived risks and higher costs associated with reuse. Despite these challenges, the research identifies significant opportunities for advancing material reuse. These include the potential for implementation of technological advancements in material processing, and growing public and governmental support for sustainable construction practices. The thesis goes forward by proposing strategic recommendations aimed at enhancing the adoption of reuse practices, thereby contributing to a more sustainable and resource-efficient construction sector in Sweden. / Demand trust for circular building materials
45

Estudo laboratorial de agregado reciclado de resíduo sólido da construção civil para aplicação em pavimentação de baixo volume de tráfego. / Laboratory study of recycled aggregate from construction and demolition waste to be used as a pavement material in a low volume road.

Motta, Rosângela dos Santos 29 August 2005 (has links)
A crescente quantidade de resíduos sólidos da construção civil gerada em cidades de médio e grande portes tem sido fonte de preocupação em todo o mundo em função de questões ambientais, econômicas e até sociais. Desta forma, a reciclagem dos resíduos de construção para a produção de agregados torna-se uma alternativa interessante, principalmente em função de normas e pesquisas já existentes que podem garantir sua aplicação. A pavimentação com agregados reciclados já vem sendo amplamente realizada em alguns países onde, inclusive, já existe conhecimento consolidado sobre o assunto. No Brasil, as primeiras experiências que remetem ao uso de agregados reciclados em pavimentação datam de meados da década de 80. Desde então, poucas pesquisas sobre o tema vem sendo realizadas, embora haja a necessidade de se procurar novas técnicas e materiais no setor de infra-estrutura rodoviária, uma vez que o país possui somente cerca de 10% de suas vias, muitas vezes urbanas, em condição pavimentada. Este trabalho analisa laboratorialmente aspectos físicos e de comportamento mecânico do agregado reciclado da cidade de São Paulo, a ser utilizado em camadas de base, sub-base ou reforço do subleito de pavimento, em substituição aos materiais convencionais, com enfoque em vias urbanas de baixo volume de tráfego. O estudo envolveu a análise do agregado reciclado in natura, além de sua mistura com 4% de cal ou 4% de cimento Portland, como forma de promover um aumento da resistência do material. Além disso, foram realizados alguns ensaios com brita graduada (material comumente empregado em pavimentos), a fim de comparar resultados. Concluiu-se que o agregado reciclado analisado é de uso promissor em pavimentação, dadas suas propriedades físicas e mecânicas satisfatórias, comparáveis a tradicionais materiais estabilizados granulometricamente ou mesmo a brita graduada simples. Ademais, a adição de cal ou cimento Portland apresenta-se como excelente alternativa quanto ao requisito de aumento de resistência do material reciclado. / The increasing amount of construction and demolition waste generated in medium-sized and large cities has become a source of concern all over the world due to environmental, economic and even social issues. Thus, the recycling of construction and demolition waste to produce aggregates becomes an interesting alternative mainly because of existing specifications and researches that can guarantee its application. Paving with recycled aggregates has already been largely done in some countries where there is even a consolidated knowledge about the subject. In Brazil, preliminary experiences that refer to the use of recycled aggregates in pavement layers date from the mid 80s. Since then, few researches on the subject have been conducted, although it is necessary to look for new techniques and materials in the road infra-structure sector, since the country has only about 10% of its roads, many times urban ones, in paved condition. This work analyses recycled aggregates from São Paulo City as a material to be used in base, subbase or subgrade reinforcement courses in urban roads of low-volume traffic, to replace conventional materials. So, physical and mechanical behaviour aspects of the material were observed by means of laboratory tests. This study involved the analysis of recycled aggregate in natura, as well as its mix with 4% of lime or 4% of Portland cement, to promote a gain in strength. Moreover, some tests were made using graded crushed rock (that is commonly used as a pavement material) so as to compare the results. It was concluded that recycled aggregate is promising for paving, given its satisfactory physical and mechanical properties, comparable to traditional granulometrically stabilized materials or even to simple graded crushed rock. The addition of lime or Portland cement is an excellent alternative concerning the increase in strength of those recycled materials.
46

Proposição de critérios técnicos e ambientais para criação de banco de solos para a região metropolitana de São Paulo. / Proposition of technical and environmental criteria for the creation of a soil bank for the metropolitan of São Paulo.

Kataguiri, Karen 21 March 2017 (has links)
Considerando a necessidade de soluções sustentáveis para a destinação de solos de escavação de obras em áreas urbanas, este estudo apresenta a caracterização de materiais de escavação recebidos em um aterro de resíduos de construção civil (RCC) localizado na Região Metropolitana de São Paulo (MRSP). As amostras foram classificadas visualmente como predominantemente solo de escavação ou mistura de diferentes tipos de RCC, e submetidas a testes de caracterização química, mineralógica, ambiental e geotécnica. Os materiais de escavação destinados ao aterro são compostos, principalmente, por mistura de solos e outros tipos de RCC. Materiais cimentícios estão presentes em todas as frações granulométricas das amostras. As propriedades geotécnicas dos solos de escavação não são prejudicadas pela mistura com outros tipos de RCC. Os materiais são basicamente granulares e bem graduados, com resistência mecânica adequada para algumas aplicações geotécnicas ou de pavimentação. Nitrato e sulfato dissolvidos podem poluir aquíferos e águas superficiais; entretanto, as concentrações observadas não representam risco à saúde. No caso de concentrações superiores aos valores máximos permitidos pela regulamentação de resíduos, a avaliação do risco a possíveis receptores deve ser efetuada conforme o uso pretendido da construção. Foi sugerido um critério preliminar de triagem de materiais de escavação para potenciais reusos na RMSP. / Considering the need of sustainable solutions for disposal of excavation soils from construction works in urban areas, this study presents characterization of excavation materials received in a CDW landfill located in the Metropolitan Region of São Paulo (MRSP). Samples were visually classified as predominantly excavation soil or mixtures of different types of CDW, and submitted to chemical, mineralogical, environmental and geotechnical characterization tests. The excavation material disposed of in the landfill is mainly composed of a mixture of soils and other types of CDW. Cementitious materials are present in all grain size fractions. Geotechnical properties of excavation soils are not impaired by the mixture with other types of CDW. The materials were basically granular and well-graded, with appropriate mechanical resistance for some geotechnical or pavement applications. Dissolved nitrate and sulfate may pollute aquifers and superficial waters; however, the observed concentrations do not represent health concern. In the case of concentrations higher than the maximum allowed values, risk assessment to possible receptors shall be carried out according to the intended construction purpose for potential reuse screening. A preliminary criteria screening for potential reuses was suggested for excavation materials of the MRSP.
47

SUBSÍDIOS PARA ELABORAÇÃO DE PLANO DE GERENCIAMENTO DE RESÍDUOS DA CONSTRUÇÃO E DEMOLIÇÃO

Veiga, Rosângela Mendanha da 29 February 2008 (has links)
Made available in DSpace on 2016-08-10T10:50:22Z (GMT). No. of bitstreams: 1 ROSANGELA MENDANHA DA VEIGA - PARTE 1.pdf: 15620641 bytes, checksum: 5d52ffa5ca3a1f10d3bd59d5c8266066 (MD5) Previous issue date: 2008-02-29 / The civil construction is one of the human activities that cause more impacts to the environment. It produces significant alterations in the environment along all its productive chain, especially in its principal chain where occurs the generation of construction and demolition waste, which contributes effectively to the aggravation of the questions related to the environment. The construction and demolition waste is produced in a great volume and generally does not receive appropriate destination. At the same time there is a lack of municipal policies and management plans for this kind of waste. In January 02nd 2003 came into force the CONAMA Resolution number 307 of July 5th 2002 that establishes directives, criteria and proceedings for the construction and demolition waste management. It was waited that the private sector, and mainly the public one, would take the necessary measurements to carry out the mentioned resolution, however very little or hardly anything was carried out by the social actors involved in the question and by the Brazilian cities. In most of them the corrective management prevails, and this kind of waste needs its own management. Due to this situation, it was tried to identify municipal experiences, in accordance with the legislation and standards referring to the construction and demolition waste, which could show possible solutions. There were carried out two case studies, whose focus was detained to a different management of construction and demolition waste in the cities of Belo Horizonte, the most important experience in Brazil, and São José do Rio Preto, which, in a short time, following the steps of Belo Horizonte, became also a model and a reference. The present research is a contribution to supply subsidies for the preparation of public policies and plans related to the introduction of a different management of construction and demolition waste in the Brazilian cities. / A construção civil é uma das atividades humanas mais impactantes do ponto de vista ambiental. Produz significativas alterações no meio ambiente ao longo de toda sua cadeia produtiva, sendo que na sua cadeia principal ou de processos ocorre a geração de Resíduos de Construção e Demolição (RCD), o que contribui efetivamente para o agravamento das questões relacionadas ao saneamento ambiental. Além de ser gerado em grande volume, o RCD, geralmente, não recebe destinação adequada. Concomitantemente existe uma carência de políticas e planos municipais de gerenciamento para este resíduo. Em 02 de Janeiro de 2003 entrou em vigor a Resolução CONAMA 307 de 5 de julho de 2002 que estabelece diretrizes, critérios e procedimentos para a gestão dos resíduos da construção civil. Esperava-se que o setor privado e, principalmente, o público, tomassem as providências necessárias para cumprir a referida resolução, porém muito pouco ou quase nada foi realizado por parte dos atores sociais envolvidos na questão e dos municípios brasileiros. Na maioria deles prevalece a Gestão Corretiva, sendo que esse resíduo necessita de gerenciamento próprio. Diante deste quadro, buscou-se identificar experiências municipais, em conformidade com a legislação e normas referentes ao RCD, que pudessem nortear possíveis soluções. Assim, foram realizados dois Estudos de Casos Observacionais, cujo foco deteve-se na Gestão Diferenciada do RCD nas cidades de Belo Horizonte, considerada a experiência mais importante em Gestão Diferenciada do RCD no Brasil, e São José do Rio Preto que, seguindo os passos de Belo Horizonte, em pouco tempo tornou-se também um modelo e uma referência. A presente pesquisa é uma contribuição para fornecer subsídios para a elaboração de políticas públicas e planos correlatos para a implantação da Gestão Diferenciada do RCD nos municípios brasileiros.
48

TRATAMENTO DE EFLUENTE PROVENIENTE DA LAVAGEM DE RESÍDUOS DE CONSTRUÇÃO E DEMOLIÇÃO

Silva, Helenton Carlos da 31 March 2016 (has links)
Made available in DSpace on 2017-07-20T13:41:59Z (GMT). No. of bitstreams: 1 HELENTON CARLOS DA SILVA.pdf: 14476259 bytes, checksum: 0a42181cc955a30bfda103115227d8ab (MD5) Previous issue date: 2016-03-31 / This paper aims to propose a treatment system for wastewater from the construction and demolition waste washing water (RCD). Therefore, the physico-chemical characterization of a lot of stuff, from washing effluent in different proportions of water was performed. A mass of material was washed following the criteria established in the Brazilian Norm Standard MERCOSUR 46 of 2003, for determination by physical removal of the pulverulent material (particles smaller than 75 μm), which damage the quality of the mortar. The RCD has been classified as fine aggregate with a maximum size of 4,8 mm and feature average fineness modulus of 2,77. For washing RCD according to the specified in the standard no specific amount of water for performing the process. Thus, the present study aimed to optimize this amount obtaining an optimum rate of mass RCD for a water volume of 1,67 : 1,00. The resulting effluent from the washing of ash RCD presented pH between 7,54 and 8,34, acidity from 9,09 to 15,25 mg CO2.L-1 and 10,33 to 17,33 mg of CaCO3.L-1 . The turbidity of 70,93 NTU varied more than 300 NTU. Following proposed treatment for the effluent with three treatment options: a sedimentation tank; by combined sedimentation tank in series with sand filter; processes for coagulation, flocculation and sedimentation. And after the analysis of these three systems, it was observed that all showed efficiency in some parameters analyzed, highlighting that the turbidity was removed by 99 % in the three cases. The process was less efficient coagulation, flocculation and settling by the use of the coagulant of aluminum sulfate in 100 mg.L-1 concentration. It also emphasizes that the COD was removed more than 90 % in the three proposed processes. Thus, it was concluded that the best treatment system was observed by physical and biological combined removal by settling tank in series with a sand filter. / Este trabalho tem por objetivo propor um sistema de tratamento para o efluente proveniente da água de lavagem de resíduos de construção e demolição (RCD). Para tanto, foi realizada a caracterização físico-química de um lote do material, do efluente proveniente da lavagem em diferentes proporções de água. Uma massa do material foi lavada seguindo os critérios estabelecidos na Norma Brasileira Regulamentadora Norma MERCOSUL 46 de 2003, para a determinação por remoção física do material pulverulento (partículas menores que 75 μm), que prejudicam a qualidade da argamassa. O RCD foi classificado como agregado miúdo,com dimensão máxima característica de 4,8 mm e módulo de finura médio de 2,77. Para a lavagem do RCD de acordo com o especificado na norma não há quantidade específica de água para a realização do processo. Desta forma o presente estudo visou otimizar essa quantidade obtendo-se uma taxa ótima de massa de RCD para um volume de água de 1,67 : 1,00. O efluente resultante da lavagem do RCD cinza apresentou pH entre 7,54 e 8,34, acidez de 9,09 a 15,25 mg de CO2.L-1 e 10,33 a 17,33 mg de CaCO3.L-1. A turbidez variou de 70,93 NTU a mais que 300 NTU. Na sequência foi proposto o tratamento para o efluente com três opções de tratamento: por tanque de sedimentação; por tanque de sedimentação combinado em série com filtro de areia; por processos coagulação, floculação e sedimentação. E após a análise desses três sistemas, observou-se que todos apresentaram eficiência em alguns parâmetros analisados, destacando-se que a turbidez foi removida em 99 % nos três processos. O processo menos eficiente foi à coagulação, floculação e sedimentação com a utilização do coagulante sulfato de alumínio em 100 mg.L-1 de concentração. Destaca-se ainda que a DQO foi removida mais de 90 % nos três processos propostos. Assim, concluiu-se que o melhor sistema de tratamento observado foi por remoção física e biológica por tanque de sedimentação combinada em série com filtro de areia.
49

Análise da influência da massa específica de agregados graúdos provenientes de resíduos de construção e demolição no desempenho mecânico do concreto. / Analyses of the influence of construction and demolition waste coarse aggregate porosity on the mechanical performance of concrete.

Carrijo, Priscila Meireles 16 March 2005 (has links)
Em virtude de muitas dúvidas ainda existentes, referentes ao desempenho e durabilidade dos concretos com agregados de RCD reciclados, sua utilização até o momento é limitada, não chegando aos níveis desejáveis e necessários. Somam-se a essas, a falta de gestão, de ferramentas de controle de qualidade, de normalização e de melhoria nas operações unitárias de beneficiamento do RCD. Os agregados reciclados apresentam características físicas e comportamento bastante heterogêneo, o que dificulta sua utilização com confiabilidade, principalmente em situações que demandam um maior controle e responsabilidade por parte do material empregado, como no caso de concretos estruturais. A porosidade e absorção dos agregados reciclados influenciam, de maneira significativa, as propriedades do concreto fresco e endurecido. Mesmo que estes sejam separados por fases (concreto, argamassa e cerâmica), é possível encontrar porosidades variadas dentro de uma mesma fase. Portanto, não se pode afirmar que o comportamento de concretos com agregados de mesma fase será homogêneo. Por este motivo, para esta pesquisa os agregados reciclados vermelho (predominância visual de cerâmica vermelha) e cinza (predominância visual de materiais cimentícios) foram separados em quatro faixas de densidade (d<1,9; 1,9<d<2,2; 2,2<d<2,5; d>2,5 g/cm³). Foram analisados os resultados de resistência à compressão, módulo de elasticidade, absorção de água, índice de vazios, massa específica e consumo de cimento. Os resultados obtidos nos ensaios de avaliação das propriedades físicas e mecânicas dos concretos usando agregados vermelho e cinza e concretos com agregados convencionais foram analisados para quantificar a influência da porosidade dos agregados. Verificou-se que a influência da natureza mineralógica dos agregados (vermelho ou cinza) influenciou as propriedades de maneira menos intensa que sua porosidade. Além disso, os concretos produzidos com RCD de densidade inferior a 2,2 g/cm3 apresentaram menor resistência e módulo e maior absorção de água, tornando o concreto muito menos eficiente para aplicações estruturais. A separação dos agregados em faixas de densidade garantiu um comportamento bastante homogêneo dos concretos, quando se utilizou agregados da mesma faixa. Com isso, foi possível estabelecer uma correlação entre a porosidade dos agregados e o desempenho mecânico dos concretos. A separação por faixas de densidade se mostrou como um critério confiável de classificação e caracterização dos agregados para a fabricação de concretos, podendo ser utilizado em conjunto com a separação visual normalmente empregada. / Construction and Demolition Waste (CDW) aggregates have not yet been widely used in concrete applications due to the many doubts relating to its performance and durability. The lack of an appropriate CDW recycling management, standardization, an innovative process technology as well as faster, cheaper and accurate quality control techniques also limits the use of this material. The reliable use of recycled CDW aggregates, especially in major situations such as in structural concrete, is still difficult due to its heterogeneous physical characteristics and behavior. Fresh and hard concrete properties are significantly influenced by recycled aggregate porosity and water absorption. Even if aggregates are separated in phases by hand sorting (concrete, mortar and ceramics) it is possible to find different porosities within the same phase and, for that reason, concretes will also present heterogeneous behavior. In this direction, the two types of recycled aggregates used in this research – named red (mainly constituted of red ceramics) and grey (mainly constituted of cimenticious materials) – were separated in four density classes (d<1.9; 1.9<d<2.2; 2.2<d<2.5; d>2.5 g/cm³). The compressive strength, elastic modulus, water absorption, specific weight and cement consumption of concretes were analyzed. The mechanical and physical properties of concretes were studied in terms of the recycled aggregate porosity and comparisons of results obtained with concretes using red or grey recycled aggregates and with ordinary aggregates were carried out. It was verified that the concretes properties were mostly influenced by the aggregates porosity when compared to its phase. Recycled aggregates with bulk specific gravity under 2.2 g/cm3 provided a significant reduction of the compressive strength and the elastic modulus and an increase of water absorption, producing concretes less efficient for structural applications. The behaviour of concretes produced by aggregates within the same density class was found to be homogeneous. A relation between porosity of aggregates and mechanical performance of concrete was verified. The heavy media separation can be used, together with the hand sorting, as an efficient and reliable aggregate quality control method for the production of concretes.
50

Modelo para estimar a geração de resíduo de madeira de uso provisório em obras de edifícios verticai

Vargas, Luciano Lopes Amor 12 January 2017 (has links)
Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2017-05-30T11:58:58Z No. of bitstreams: 1 Luciano Lopes Vargas Amor_.pdf: 2139833 bytes, checksum: f496319c4cf4ede22ca6b861b4855664 (MD5) / Made available in DSpace on 2017-05-30T11:58:58Z (GMT). No. of bitstreams: 1 Luciano Lopes Vargas Amor_.pdf: 2139833 bytes, checksum: f496319c4cf4ede22ca6b861b4855664 (MD5) Previous issue date: 2017-01-12 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / O setor da construção civil é hoje um grande gerador de resíduos, o que impacta negativamente o meio ambiente. Tanto a fase de projeto quanto a de execução de obras podem ocasionar essa geração. Quantificar o resíduo gerado em uma obra é fundamental para ter um controle do problema. A madeira, principal material empregado no uso provisório nos canteiros de obras, pode gerar grande volume de resíduo, sendo que o mesmo é descartado tão logo a obra termina, havendo pouco reaproveitamento ou reciclagem da mesma. Quantificar esse resíduo pode facilitar a gestão e o controle do mesmo, possibilitando a sustentabilidade de um material nobre e importante para o desenvolvimento da construção civil. O objetivo deste estudo consiste em propor um modelo para estimar a geração de resíduos de madeira de uso provisório em obras de edifícios verticais, analisando suas características de projeto e de execução. A estratégia de pesquisa utilizada foi o estudo de casos múltiplos, com coleta de dados de obras localizadas na região metropolitana de Porto Alegre, feitos através de entrevistas, observações in loco e análise de projetos. Ao todo, a amostra estudada foi formada por 22 obras de 11 empresas. Como resultado, foram gerados modelos estatísticos, a partir de regressão múltipla, contendo a variável dependente - volume de resíduos de madeira – e as variáveis independentes relativas ao projeto – número de pavimentos, número de pavimentos em subsolo, volume de concreto executado – e à execução - comprimento linear de tapume em madeira, índice de uso da madeira na confecção dos equipamentos de proteção coletiva e instalações provisórias. O modelo proposto possui R² ajustado de 0,893, indicando que é capaz de explicar 89,3% do fenômeno. As variáveis que mais impactaram foram o número de pavimentos e o número de pavimentos em subsolo. O modelo permite que as empresas construtoras possuam maior controle sobre o volume de resíduo de madeira gerado pelas suas obras, e possibilita realizar ações efetivas em prol da gestão dos resíduos, havendo maior controle e a redução dos mesmos. Possibilita também aplicá-lo em outras obras de diferentes regiões, considerando as características de projeto e de execução locais. / The construction industry is today a great generator of waste, which has a negative impact on the environment. Both the design and execution phases of works can cause this generation. To quantify the waste generated in a work is fundamental to control the problem. Wood, the main material used temporarily in construction sites, can generate a large volume of waste, which is discarded as soon as the work is finished, with little reuse or recycling. Quantifying this waste can facilitate the management and control of the same, allowing the sustainability of a material which is important and noble for the development of civil construction. The aim of this study is to propose a model to estimate the generation of wood waste used temporarily in vertical construction, analyzing their design and execution characteristics. The research strategy used was the study of multiple cases, with data collection of works located in the metropolitan region of Porto Alegre, made through interviews, in situ observations and project analysis In all, the sample studied was formed by 22 works from 11 companies. As a result, statistical models were generated from multiple regression, containing the dependent variable - volume of wood waste - and the independent variables related to the project - number of floors, number of floors in subsoil, volume of concrete executed - and execution - linear length of siding in wood, the index use of wood in the production of collective protection equipment and temporary facilities. The proposed model has an adjusted R² of 0.893, indicating that it is able to explain 89.3% of the phenomenon. The variables that most impacted it were the number of floors and the number of floors in subsoil. The model allows construction companies to have greater control over the volume of wood waste generated by their works, and enables effective actions to be taken in favor of waste management, with greater control and reduction of waste. It can also be applied in other works from different regions, considering the local design and execution characteristics.

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