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Pavimentos intertravados de concreto utilizando resíduos de pneus como material alternativo / Concrete paving interspersed with tire residues as alternative materialFioriti, Cesar Fabiano 01 June 2007 (has links)
A utilização de resíduos tem se mostrado como uma boa alternativa na redução do impacto causado pelo consumo desordenado de matéria-prima e pela redução das áreas de disposição, em virtude do grande volume de resíduos descartados a cada ano em todo mundo. Neste contexto se inserem os resíduos de pneus provenientes da recauchutagem. Este trabalho foi desenvolvido com o objetivo de estudar algumas propriedades de pavers de concreto, com substituição parcial do agregado por resíduos de pneus. Para a produção dos pavers foram consideradas as faixas de consumo de cimento Portland de 292,84 kg/m³, 323,06 kg/m³ e 347,00 kg/m³, e os níveis de incorporação dos resíduos estudados foram de 8%, 10%, 12%, 15% e 20%, em volume. As propriedades foram: resistência à compressão, absorção de água, resistência ao impacto, resistência à abrasão profunda e expansão por umidade. Os resultados mostram que ocorre queda na resistência à compressão. Na absorção de água, não podemos afirmar que essa propriedade é afetada de maneira negativa. Os pavers demonstraram grande capacidade de absorção de energia (tenacidade). Os resultados de resistência à abrasão mostram-se interessantes para a aplicação em ambientes com baixas solicitações. A expansão por umidade não afetará o intertravamento dos pavers. Dessa forma, os resultados mostraram viabilidade na utilização dos pavers com resíduos de pneus em pavimentação intertravada com solicitações leves. / Concerns regarding the environment and shortage of natural resources have led the way for sustainable alternatives. The recycling process seems to be a suitable alternative to minimize the use of natural resources as well as the lack of proper disposal sites caused by the large amounts of discarded waste worldwide. Within this context, rubber residues from recapped tires are used for insertion. This work was developed with the objective of studying some of the properties of concrete paving, with partial substitution of the aggregate for tire residues. For the production of pavers the bands of Portland cement consumption was considered at 292,84 kg/m³, 323,06 kg/m³ and 347,00 kg/m³, and the levels of residues incorporation at 8%, 10%, 12%, 15% and 20%, in volume. The studied properties were: compressive strength, water absorption, impact resistance, deep abrasion and expansion resistance to humidity. The results show decrease in the compressive strength. The water absorption does not undergo negative influence. Pavers demonstrated substantial capacity for energy absorption (tenacity). The results of abrasion resistance reveal interesting applications for locales with low degree of demands. Expansion by humidity will not affect the interspersing of pavers. However, the results have shown viability in the use of pavers interspersed with tire residues in asphalt with light load demands.
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Pavimentos intertravados de concreto utilizando resíduos de pneus como material alternativo / Concrete paving interspersed with tire residues as alternative materialCesar Fabiano Fioriti 01 June 2007 (has links)
A utilização de resíduos tem se mostrado como uma boa alternativa na redução do impacto causado pelo consumo desordenado de matéria-prima e pela redução das áreas de disposição, em virtude do grande volume de resíduos descartados a cada ano em todo mundo. Neste contexto se inserem os resíduos de pneus provenientes da recauchutagem. Este trabalho foi desenvolvido com o objetivo de estudar algumas propriedades de pavers de concreto, com substituição parcial do agregado por resíduos de pneus. Para a produção dos pavers foram consideradas as faixas de consumo de cimento Portland de 292,84 kg/m³, 323,06 kg/m³ e 347,00 kg/m³, e os níveis de incorporação dos resíduos estudados foram de 8%, 10%, 12%, 15% e 20%, em volume. As propriedades foram: resistência à compressão, absorção de água, resistência ao impacto, resistência à abrasão profunda e expansão por umidade. Os resultados mostram que ocorre queda na resistência à compressão. Na absorção de água, não podemos afirmar que essa propriedade é afetada de maneira negativa. Os pavers demonstraram grande capacidade de absorção de energia (tenacidade). Os resultados de resistência à abrasão mostram-se interessantes para a aplicação em ambientes com baixas solicitações. A expansão por umidade não afetará o intertravamento dos pavers. Dessa forma, os resultados mostraram viabilidade na utilização dos pavers com resíduos de pneus em pavimentação intertravada com solicitações leves. / Concerns regarding the environment and shortage of natural resources have led the way for sustainable alternatives. The recycling process seems to be a suitable alternative to minimize the use of natural resources as well as the lack of proper disposal sites caused by the large amounts of discarded waste worldwide. Within this context, rubber residues from recapped tires are used for insertion. This work was developed with the objective of studying some of the properties of concrete paving, with partial substitution of the aggregate for tire residues. For the production of pavers the bands of Portland cement consumption was considered at 292,84 kg/m³, 323,06 kg/m³ and 347,00 kg/m³, and the levels of residues incorporation at 8%, 10%, 12%, 15% and 20%, in volume. The studied properties were: compressive strength, water absorption, impact resistance, deep abrasion and expansion resistance to humidity. The results show decrease in the compressive strength. The water absorption does not undergo negative influence. Pavers demonstrated substantial capacity for energy absorption (tenacity). The results of abrasion resistance reveal interesting applications for locales with low degree of demands. Expansion by humidity will not affect the interspersing of pavers. However, the results have shown viability in the use of pavers interspersed with tire residues in asphalt with light load demands.
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Design, Fabrication and Analysis of a Paver Machine Push Bar MechanismPalnati, Mahendra 05 November 2015 (has links)
Now-a-days, the major challenge that’s being faced by the concrete industry is the cleaning of concrete handling equipment. Concrete consists of aggregates, which harden with time, and the transportation of concrete mixture within the plant is a significant problem. This will not only increase the overall maintenance cost, but will lead to loss of raw materials, affect the rate of production, and reduce the lifetime of concrete handling equipment.
The present study focuses on the design and implementation of an adaptive cleaning mechanism in the concrete industry and its importance in achieving efficient cleaning, which is tested to verify its performance in the Paver production plant. The goal of this study is to provide practical evidence about the importance of adaptive cleaning mechanisms for industrial applications.
The first chapter gives a detailed introduction about pavers and the production process, the cause of material loss that occurs during transportation of wet concrete mixture inside a paver plant, and its effect on handling equipment and work environment. The second chapter explains design and working of the paver machine push bar mechanism, which can be implemented in a hydraulic press production process of pavers. The third chapter includes analysis and results of the mechanism obtained using Solidworks and Autodesk Inventor followed by observations that are achieved based on practical application of this mechanism in a paver production plant.
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Estudio, análisis y diseño de secciones permeables de firmes para vías urbanas con un comportamiento adecuado frente a la colmatación y con la capacidad portante necesaria para soportar tráficos ligerosRodríguez Hernández, Jorge 11 July 2008 (has links)
Los firmes permeables forman parte de la tendencia de construcción sosteniblecomo uno de los Sistemas Urbanos de Drenaje Sostenible (SUDS) más completos. Paraestudiar la capacidad de infiltración en laboratorio, se ha desarrollado el ensayo deresistencia a la colmatación con el Infiltrómetro Cántabro Fijo (ICF). Este ensayo es unaherramienta eficaz para la caracterización de diferentes tipos de pavimentos permeables,exponiéndolos a un aporte conocido de agua, variando el estado de colmatación y lainclinación de la superficie. Además, para estudiar la capacidad de infiltración encampo, se ha desarrollado el Infiltrómetro Cántabro Portátil (ICP), el cual permiteidentificar claramente cualquier tipo de superficie, permeable o impermeable, así comosu capacidad de infiltración. Respecto a la degradación de los materiales, se haanalizado la afección de los vertidos de hidrocarburos sobre mezclas bituminosasporosas fabricadas con distintos tipos de betunes. Por último, se han construido modelosde firmes permeables en el Laboratorio (FIDICA), en el Campus de Santander de laUniversidad de Cantabria y en el aparcamiento experimental de la Guía en Gijón. / Pervious pavements are part of the trend of sustainable construction as one of themost complete Sustainable Urban Drainage Systems (SUDS). The clogging resistancetest with the Fixed Cantabrian Infiltrometer (FCI) has been developed to study theinfiltration capacity in laboratory. The FCI is an effective tool for the characterization ofdifferent pervious pavements types, exposed to a known contribution of water, varyingclogging conditions and slope. Besides, the Portable Cantabrian Infiltrometer (PCI) hasbeen developed to study the infiltration capacity in field. The PCI allows clearlyidentifying any type of surface, pervious or impervious, as well as its clogging level.Regarding the materials degradation, the affection of hydrocarbons leakages overporous asphalt has been analysed. Lastly, models of pervious pavements have been builtin the FIDICA Laboratory and in the Santander Campus of the University of Cantabria,besides several experimental parking bays in La Guía, Gijón.
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Development and Engineering Properties of Construction Materials Made Using Melted Plastics Wastes as the Only Binding PhaseThiam, Moussa 07 September 2021 (has links)
Modernization has brought about steady increase in the consumption of goods and services by human societies across the globe, which mostly driven by both population growth and the change of individual living standards. This, of course, leads to an ever-increasing waste production that ends up in landfills and very often as a source of pollution on natural ecosystems, especially in the low and middle-income countries where waste management is almost inexistent.
The management of waste streams is a huge challenge for developed countries as well, where societal and environmental impacts are visible despite massive investments in waste management. One of the most problematic waste materials is plastic, which can remain in nature for over 100 years without degradation, leading to serious environmental concerns. As one of the most significant innovations of the 20th century, plastic is a widely used and cost-effective material for many applications. After their useful lifetimes, their management is problematic. Thus, robust and innovative approaches of managing such waste material are needed in order to mitigate the problem.
One of the innovative approaches of tackling the menace cause by plastic waste is through its incorporation into the construction materials. This thesis seeks to address this problem by exploring the use of melted plastic wastes (High Density Poly Ethylene, HDPE and Low Density Poly Ethylene, LDPE) as binder in developing new construction materials (mortar with melted plastic as the only binder, MPB and Plastic Waste Crete, PWC) as an alternative to partially replace traditional concrete and mortar, or finding other engineering uses for this type of waste.
Worldwide, about 190 m3 of concrete is poured every second, which translates to 6 billion m3 per year and making it, one of the most widely used manufactured materials. However, the production of concrete requires water and cement. Cement is expensive, and its production contributes to the emission of environmentally polluting gases. Replacing this binding element with recycled plastic derivatives would have significant economic and environmental benefits. In addition to the elimination of cement cost, this will result in water savings, which is especially important for areas without fresh water scarcity.
Some researchers have used plastics in concrete and mortars as additives and/or replacement for fine and coarse aggregates. In addition, different types of plastics have been used in bitumen as an additive to reduce construction cost and improve sustainability by adding value to wastes materials. However, there is paucity of technical information about the use of the melted HDPE and LDPE plastic wastes as the only binding phase in concrete- or mortar-like materials. Moreover, many parameters such as preparation conditions, field variables, constituent elements, and final applications have impacts on the performance of construction materials
Thus, the key objective of this PhD research is to develop the mortar with plastic binder (MPB) and PlasticWasteCrete (PWC) by using molten HDPE and LDPE plastic wastes as the only binder as well as to investigate the engineering properties of these new types of construction materials.
The plastic contents of 45%, 50%, 60% and 65% and HDPE to LDPE ratios of 40/60, 50/50, and 60/40 were selected for the experimental tests. Clean river sand was used as the only aggregate for the MPB, while both sand and gravel were used for the PWC. Various tests were then performed on prepared MPB and PWC samples at different curing times from early to advanced ages to assess their engineering properties. These tests were conducted in accordance with the ASTM standards to evaluate the mechanical properties (compressive strength and splitting tensile strength), permeability and density of the MPB and PWC materials. Additional tests were carried out to analyze the products at the microstructural level (optical microscope, SEM, MIP and thermogravimetric analysis) to gain an insight into the microstructural properties of the developed materials and how that affect their engineering properties.
The compressive strength tests revealed the optimal plastic content for the MPB and PWC with the best strength performance. The average compressive strength values for various optimal formulations after 28 days were found to be in the range of 9 to 18 MPa. The splitting tensile strength for the new materials from 1 to 28 days of curing time, were found to be between 1 and 5 MPa. The average hardened density of the MPB and PWC is about 2 g/cm3, which makes them lightweight material according to RILEM classification. In addition, various absorption tests (capillary and immersion) were performed on different MPB and PWC samples, and the obtained results showed that they are porous materials having lower rate of absorption than the traditional cementitious materials (mortar, concrete). This observation was supported by the results from both MIP and SEM analyses. Finally, thermogravimetric analysis provided interesting details on the thermal decomposition of the new materials, with significant changes or mass loss for these products being observed only at temperatures higher than 300°C.
The findings from this study suggest MPB and PWC made with melted plastic waste as the only binder have a promising potentials for use in construction. The research conducted in this PhD study offers a good understanding of the engineering properties of the materials as well as the optimal formulations that yield best performance in terms of strength and durability. In summary, it provides useful technical information and tools on the MPB and PWC that will contribute in setting guidelines on the optimal applications of these products in the field of construction in order to have safe, durable and cost-effective structures.
Résumé
Avec la modernisation de nos sociétés, les habitudes ont considérablement changé, ainsi, on observe une forte consommation des biens et services, due à l’augmentation de la population et l’amélioration de leurs conditions de vie. Ce qui conduit à une augmentation considérable des quantités des déchets qui terminent leurs cycles au niveau des décharges ou dans les océans/fleuves devenant ainsi une source de source de pollution des écosystèmes naturels, surtout dans les pays à revenu faible et intermédiaire avec des systèmes défaillants ou moins performants de gestion des déchets. La gestion des flux de déchets est aussi un défi pour certains pays développés, où les impacts sociaux et environnementaux sont visibles en dépit des investissements massifs dans ce secteur.
Parmi ces déchets, nous avons les plastiques, l’une des innovations du 20e siècle avec des qualités versatiles et coût faible, se trouve partout dans nos vies quotidiennes. Après leur utilisation, les plastiques deviennent des déchets qui peuvent rester dans la nature plus de 100 ans sans aucune dégradation, avec des conséquences néfastes sur l’Homme et l’environnement. Ainsi, une approche robuste et innovante de gestion de ces déchets est nécessaire afin d'atténuer leurs impacts. L'une des approches innovantes pour réduire l’impact causé par les déchets plastiques consiste à les incorporer dans les matériaux de construction.
Ainsi, le problème est abordé dans cette thèse en développant des technologies permettant de recycler les plastiques fondus comme liant dans les nouveaux matériaux de construction (MPB et PWC), afin d’offrir une alternative pour remplacer partiellement le béton / mortier traditionnel.
Le béton est l’un des matériaux les plus utilisés au monde, avec environ 190 m3 coulés chaque seconde, correspondant à 6 milliards de m3 par an. Cependant, la production de béton nécessite de l'eau et du ciment. Le ciment coûte cher et sa production contribue à l'émission de gaz polluants l'environnement. Le remplacement d'une partie du béton traditionnel par un matériau à base des déchets plastique aura des avantages économiques, sociaux et environnementaux importants.
Allant dans ce sens, certains chercheurs ont utilisé les plastiques dans le béton et le mortier comme additifs et / ou substituts des matériaux granulaires tels que le sable et le gravier. Aussi, différents types de plastiques ont été utilisé dans le bitume comme additif pour réduire les coûts de construction et améliorer la durabilité, ainsi contribuer à donner de la valeur aux déchets. Cependant, jusqu'à présent, il existe peu d’informations techniques sur l'utilisation de déchets plastiques (HDPE et LDPE) fondus comme seuls liants pour développer de nouveaux types de matériaux de construction. En plus, plusieurs facteurs (les conditions de préparation, les éléments constitutifs, les applications finales, etc.) ont un impact sur les caractéristiques des matériaux de construction.
Ainsi, l'objectif de cette recherche doctorale est de développer des nouveaux matériaux de construction (MPB et PWC) en utilisant les déchets plastiques fondus (HDPE et LDPE) comme seul liant, puis déterminer les propriétés caractéristiques de ces matériaux afin de trouver la formulation optimale conduisant à la meilleure résistance. En plus de l'élimination du coût du ciment, cette technologie permet aussi de faire des économies d'eau, bénéfique surtout pour les zones avec des difficultés d'accès à l’eau potable. Cela contribuera à la réduction des coûts de la construction en utilisant les produits innovants comme alternative au béton / mortier conventionnel.
Un vaste programme expérimental, comprenant des tests à petite et grande échelle, a été développé afin d'atteindre les objectifs de cette étude de doctorat. La campagne expérimentale a comporté différentes étapes comprenant la sélection des matériaux, la détermination de la formulation optimale et les conditions appropriées pour la préparation des matériaux susmentionnés. Par la suite, pour une meilleure compréhension du comportement technique et des propriétés du produit final, divers tests ont été effectué sur les matériaux préparés à différents temps de durcissement. Ces tests ont été menés conformément aux normes ASTM pour évaluer les propriétés mécaniques (résistance à la compression et à la traction), la perméabilité et la densité des nouveaux matériaux. Les expériences ont été approfondies en analysant les produits au niveau microstructural (microscope optique, SEM, MIP et analyse thermique) pour avoir un aperçu des propriétés microstructurales des matériaux développés et essayer de comprendre les relations avec leur comportement mécanique.
Les essais de compression ont permis de trouver la teneur en plastique optimale pour les matériaux (MPB et PWC) avec les meilleures valeurs de résistance. Les résistances moyennes à la compression à 28 jours pour diverses formulations étaient comprises entre 9 et 18 MPa. La résistance à la traction par fendage des nouveaux matériaux entre 1 et 28 jours se situait entre 1 et 5 MPa. La densité moyenne du béton et mortier écologique est proche de 2 g / cm3, ils peuvent donc être considérés comme des matériaux légers selon la classification RILEM. De plus, divers tests d'absorption (capillaire et par immersion) ont été réalisé sur différents échantillons de MPB et PWC, les résultats obtenus ont montré qu'il s'agit de matériaux poreux ayant un taux d'absorption plus faible que les matériaux traditionnels contenant du ciment. Plusieurs analyses microstructurales ont été réalisées sur différents échantillons des nouveaux produits (MPB et PWC) et les matériaux cimentaires traditionnels ont été utilisés pour renforcer notre compréhension. Enfin, l'analyse thermique a fourni des détails intéressants sur la décomposition thermique de ces nouveaux matériaux ; des changements significatifs avec une perte de masse considérable ont été observés seulement pour des températures supérieures à 300 ° C.
Les résultats de ces essais permettent d'acquérir une bonne compréhension des propriétés techniques des nouveaux matériaux (MPB et PWC) ainsi que de déterminer les teneurs optimales en plastique conduisant aux meilleures performances en termes de résistance et de durabilité. Ainsi, les recherches menées dans cette étude de doctorat fournissent des informations techniques et des outils utiles sur le MPB et le PWC; et contribueront à installer des bases pour guider les applications optimales de ces nouveaux produits dans le domaine de la construction afin d'avoir des structures sûres, durables et rentables.
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Experimental and Analytical Methodologies for Predicting Peak Loads on Building Envelopes and Roofing SystemsAsghari Mooneghi, Maryam 09 December 2014 (has links)
The performance of building envelopes and roofing systems significantly depends on accurate knowledge of wind loads and the response of envelope components under realistic wind conditions. Wind tunnel testing is a well-established practice to determine wind loads on structures. For small structures much larger model scales are needed than for large structures, to maintain modeling accuracy and minimize Reynolds number effects. In these circumstances the ability to obtain a large enough turbulence integral scale is usually compromised by the limited dimensions of the wind tunnel meaning that it is not possible to simulate the low frequency end of the turbulence spectrum. Such flows are called flows with Partial Turbulence Simulation.
In this dissertation, the test procedure and scaling requirements for tests in partial turbulence simulation are discussed. A theoretical method is proposed for including the effects of low-frequency turbulences in the post-test analysis. In this theory the turbulence spectrum is divided into two distinct statistical processes, one at high frequencies which can be simulated in the wind tunnel, and one at low frequencies which can be treated in a quasi-steady manner. The joint probability of load resulting from the two processes is derived from which full-scale equivalent peak pressure coefficients can be obtained. The efficacy of the method is proved by comparing predicted data derived from tests on large-scale models of the Silsoe Cube and Texas-Tech University buildings in Wall of Wind facility at Florida International University with the available full-scale data.
For multi-layer building envelopes such as rain-screen walls, roof pavers, and vented energy efficient walls not only peak wind loads but also their spatial gradients are important. Wind permeable roof claddings like roof pavers are not well dealt with in many existing building codes and standards. Large-scale experiments were carried out to investigate the wind loading on concrete pavers including wind blow-off tests and pressure measurements. Simplified guidelines were developed for design of loose-laid roof pavers against wind uplift. The guidelines are formatted so that use can be made of the existing information in codes and standards such as ASCE 7-10 on pressure coefficients on components and cladding.
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