Aprendizagem significativa: uma proposta de ensino e aprendizagem da geometria euclidiana espacial no ensino médio

This dissertation is a research based on the Meaningful Learning Theory, with students from the second year of High School, in the city named Capinzal do Norte, state of Maranhão. The pedagogic approach of this research focuses on what to do and how to do so students can better grasp knowledge inherent to the Euclidean Special Geometry in a more meaningful and changing way, also that information may be kept longer in their brain, so it can last longer in the present and future. The methodological strategy adopted was the research-action, followed by the constant observance of a researcher on the matter with the purpose to ensure consistent results, which come from the use of a variety of data collector instruments, such as: Concept Maps, manipulatives, educational softwares and application of evaluative tests, besides the observations made throughout the process of investigation and the diagnosis itself. It is all due to the fact that we rely on the premise that knowledge is assimilated in particular and idiosyncratic ways, which means each and every student learns in different ways and in different periods of time. That is why it is so important to develop diversified methodologies to the same subject. This research adds to the other ones related to the theoretical frameworks of the Meaningful Learning Theory, of Concept Maps, of the use of technology on the educational process and of manipulatives, which purpose is to connect their common dots. This pedagogical intervention also focuses on the construction of the educational orientations with applicability directly on class, directed specially by the Mathematics teacher of the basic education, who might use them during your teaching practice. Such guidelines established here as an educational product aim to follow the Theory's assumptions that serves as basis to this research, thus becoming an educational element with a relevant significance. The results, with which we are faced, proved overwhelming to the proposed objectives in terms of learning, which were evident in the construction of Conceptual Maps, as well as in the use of Concrete Materials, in addition to serving as a motivational element to participating students of research. The results obtained are indeed reliable in terms of learning, considered the expected goals, and made us certain that the way we have approached the subject is consistent with a holistic education and that at the same time values the tiniest details, which are fundamental to all the learning-teaching process.

Pollen flux off Cape Blanc

Fluxes of airborne freshwater diatoms (FD), phytoliths (PH), and pollen grains (PO) collected with sediment traps off Cape Blanc, northwest Africa, from 1988 till 1991 are presented. Both continental rainfall variations and wind mean strength and direction play a key role in the temporal fluctuations of the fluxes of eolian traces in the pelagic realm. Drier conditions in Northern Africa in 1987 could have preceded the high lithogenic input and moderate FD flux in 1988. The PH peak in summer 1988 was probably caused by increased wind velocity. Wetter rainy seasons of 1988/89 might have promoted a significant pollen production in summer 1989, and FD in late 1989 and early 1990, as well as contributed to the reduction of the lithogenic flux in 1989/90. Decreased fluxes of FD, PH and PO, and higher contribution of the 6-11 µm lithogenic fraction in 1991 would mainly reflect minor intensity and decreased amount of continental trade winds. Air-mass backward trajectories confirm that the Saharan Air Layer is predominantly involved in the spring/summer transport. Trade winds play a decisive role in the fall/winter months, but also contribute to the transport during late spring/summer. Origin of wind trajectories does not support a direct relationship between transporting wind-layers and material source areas in Northern Africa. High winter fluxes of eolian tracers and high amount of trade winds with continental origin in summer warn against a simplistic interpretation of the seasonal eolian signal preserved in the sediments off Cape Blanc, and the wind layer involved in its transport.

Failure Mechanisms and Local Scour at Coastal Structures induced by Tsunamis

On March 11 2011, an exceptionally large tsunami event was triggered by a massive earthquake offshore, the northeast coast of Japan, which affected coastal infrastructure such as seawalls, coastal dikes and breakwaters in the Tohoku region. Such infrastructure was built to protect against the Level 1 tsunamis that previously hit the region, but not for events as significant as the 2011 Tohoku tsunami, which was categorized as a Level 2 tsunami [Shibayama et al. 2013]. The failure mechanisms of concrete-armoured dikes, breakwaters and seawalls due to Level 2 tsunamis are still not fully understood by researchers and engineers. This paper investigates the failure modes and mechanisms of damaged coastal structures in Miyagi and Fukushima Prefectures, following the authors' post-disaster field surveys carried out between 2011 and 2013. Six significant failure mechanisms were identified for the coastal dikes and seawalls affected by this tsunami: 1) Leeward toe scour failure, 2) Crown armour failure, 3) Leeward slope armour failure, 4) Seaward toe and armour failure, 5) Overturning failure, and 6) Parapet wall failure, in which leeward toe scour being recognized as the major failure mechanism in most surveyed locations. The authors also propose a simple practical mathematical model for predicting the scour depth at the leeward toe of the coastal dikes, by considering the effects of the tsunami hydrodynamics, the soil properties and the type of structure. The key advantage of this model is that it depends entirely on quantities that are measurable in the field. Furthermore this model was further refined by conducting a series of hydraulic model experiments aimed to understand the governing factors of the leeward toe scour failure. Finally, based on the results obtained, key recommendations are given for the design of resilient coastal defence structures that can survive a level 2 tsunami event.

Towards Night

Sixty artists explore the nocturnal. Curated by Tom Hammick. The evening hour too gives us the irresponsibility which darkness and lamplight bestow. We are no longer quite ourselves. – Virginia Woolf, Street Haunting: A London Adventure, 1930 Towards Night is an exhibition exploring the nocturnal through paintings, prints and drawings by over sixty artists. Drawing on the nineteenth century European Romantic tradition, the show surveys contemporary and historical connections to wonderment and dystopia at dusk, twilight, night and dawn. Towards Night juxtaposes key paintings and prints by Constable, Friedrich, Munch, Nolde, Palmer and Turner, some of the best known visionaries of the Romantic tradition with contemporary artists who work with the transformative aspects of nightfall to convey emotional responses of awe, anxiety and solitude, love and loss, revelry, insomnia, and journey’s end. The exhibition opens with direct and positive responses to the natural world; Marc Chagall’s exotic dreamlike evening in The Poet Reclining (1915) sits close to eighteenth century Indian miniatures depicting brightly painted figures offset against darkening monsoon clouds, and William Crozier’s Balcony at Night, Antibes (2007), of a plant, blue and iridescent against the cool night sky. As the exhibition progresses, the dystopias become darker and more disturbing, and the connections between artists and works intensify: Emma Stibbon’s Rome Aqueduct (2011) takes on a heightened sense of pathos alongside Caspar David Friedrich’s Winter Landscape (1811); Peter Doig’s cinematic Echo Lake (1998) conjures up an increased sense of contemporary angst; and Prunella Clough’s False Flower (1993), a magical tree defying brutalism by growing out of concrete, becomes more miraculous near Night Shift (2015) Nick Carrick’s tomblike high rise. Tom Hammick’s Violetta Alone (2015) and Michael Craig Martin’s Ash Tray (2015), reinforce hedonistic aspects of night-time revelry alongside Four AM, Betsy Dadd’s young woman drinking in the early hours of the morning and L.S. Lowry’s drunken people in a pub in The Crowd (1922). In the final room, a cluster of works explores dreams and insomnia, from Louise Bourgeois’ Spirals (2010) to Munch’s lovers embracing in The Kiss (1902). Tom Hammick, curator of the show said “This exhibition has grown way beyond its original conception, to become a magnificent survey of painting and printmaking from over two hundred years based around the central tenet of night. The exhibition is a kind of painterly response to the way figurative artists use their artistic heroes as starting points for their own work, both compositionally and emotionally.” Artists featured in Towards Night: Christiane Baumgarter, Michael Craig-Martin, Julian Opie, Will Gill, Merlin James, Howard Hodgkin, WillIam Scott, Patrick Caulfield, George Shaw, Stephen Chambers, Basil Beattie, Betsy Dadd, Christopher Le Brun, L.S Lowry, Andrew Cranston, David Willetts, James Fisher, Emma Stibbon, Vija Celmins, William Blake, William Crozier, Tom Hammick, Georgia Keeling, Helen Turner, Humphrey Ocean, Julian Bell, Craigie Aitchison, Mark Wright, Ken Kiff, Matthew Burrows, Andrzej Jackowski, Sarah Raphael, Nick Bodimeade, Nick Carrick, Mary Newcomb, Hurvin Anderson, Peter Doig, Phoebe Unwin, Danny Markey, Sara Lee, Simon Burton, Susie Hamilton, Marc Chagall, Alfred Wallis, Emil Nolde, J.M.W. Turner, Prunella Clough, Samuel Palmer, Louise Bourgeois, Caspar David Friedrich, Alex Katz, Ewan Gibbs, Susie Hamilton, Andrzej Jackowski, Amanda Vesey, Edward Stott, Gertrude Hermes, Rose Wylie, Sidney Nolan, John Constable, J.M.W. Turner, Emil Nolde, Hiroshige, Edvard Munch, Samuel Palmer, Eileen Cooper, Charles Neame-Spencer, Samantha Cary.

Analyse des Ermüdungsverhaltens von Beton anhand der Dehnungsentwicklung

Die Weiterentwicklungen in der Betontechnologie führten in den letzten Jahrzehnten zu Hochleistungsbetonen mit immer höheren Festigkeiten. Der Ermüdungsnachweis wurde jedoch kaum weiterentwickelt und beinhaltet immer noch sehr grobe Herangehensweisen bei der Berücksichtigung des Materialwiderstands von Beton. Für eine grundlegende Weiterentwicklung dieses Nachweises fehlt noch das notwendige Wissen zu den Mechanismen der Betonermüdung. Das Ziel dieser Arbeit war es daher, grundlegende Erkenntnisse zum Ermüdungsverhalten hochfester Betone bei unterschiedlichen zyklischen Beanspruchungen zu ermitteln und hierdurch zu einem besseren Verständnis der Mechanismen der Betonermüdung beizutragen. In der vorliegenden Arbeit wurde das Ermüdungsverhalten eines hochfesten Betons bei Druckschwellbeanspruchung anhand der Dehnungs- und Steifigkeitsentwicklungen untersucht. Betrachtet wurden dabei die Einflüsse der bezogenen Oberspannung, der Belastungsfrequenz und der Wellenform. Zusätzlich wurden, ausgehend von in der Literatur dokumentierten Ansätzen, Versuche bei monoton steigender Beanspruchung und Dauerstandbeanspruchung vergleichend durchgeführt. Die Dehnungs- und Steifigkeitsentwicklungen werden durch die untersuchten Belastungsparameter der Ermüdungsbeanspruchung eindeutig beeinflusst. Charakteristische Zusammenhänge zwischen der Beeinflussung einzelner Kenngrößen der Dehnungs- und Steifigkeitsentwicklung und der Beeinflussung der Bruchlastwechselzahlen wurden aufgezeigt. Anhand der Dehnungen und Steifigkeiten an den Phasenübergängen konnten Hinweise auf beanspru-chungsartabhängige Gefügezustände abgeleitet werden. Die vergleichende Auswertung des Dehnungsverhaltens bei monoton steigender Beanspruchung, Ermüdungsbeanspruchung und Dauerstandbeanspruchung zeigte, dass das Ermüdungsverhalten von Beton nicht adäquat in Anlehnung an andere Beanspruchungsarten beschrieben werden kann. Die Untersuchungsergebnisse wurden in eine Modellvorstellung übertragen, die zur Beurteilung der baustofflichen Phänomene bei zyklischen Beanspruchungen geeignet ist. Dabei wurde die Hypothese aufgestellt, dass sich unterschiedlich ausgeprägte Kleinst-Gefügeveränderungen beanspruchungsabhängig einstellen, die die Entstehung und Ausbreitung von Mikrorissen beeinflussen. Die detaillierte Untersuchung der Dehnungs- und Steifigkeitsentwicklungen führte zu neuen und tiefergehenden Erkenntnissen und sollte ergänzt durch die Betrachtungen von Gefügezuständen zukünftig weiterverfolgt werden.

Die Saurierfährten im Naturdenkmal Münchehagen

Nearly 256 footprints of sauropods are exposed on the floor of an abandoned quarry, situated west of Hannover, where quartzitic sandstones of Berriasian age were formeriy exploited. A part of the traces can be grouped to 8 tracks, one of which was named Rotundichnus muenchehagensis by Hendricks 1981. Additionally, a track composed of bird-like footprints of a biped dinosaur is present. The dinosaurs lived within the semiaquatic, densely wooded estuary System, which was protected by sand bars against the open sea of the Lower Saxonian Basin.

Avaliação de Ciclo de Vida Energético (ACVE) de sistemas de vedação de habitações

Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2015.

Sedimenttexturen der Sohlbankfläche im Naturdenkmal "Saurierfährten Münchehagen" (Berrias), Rehburger Berge : Rippelmarken und Ichnofossilien als Grundlage einer Deutung des Ablagerungsraumes

Die Gesteine des bearbeiteten Aufschlusses, dem Naturdenkmal "Saurierfährten Münchehagen" bei Münchehagen (Rehburger Berge), liegen stratigraphisch in der Bückeberg-Formation des Berrias (Wealden). Aufgeschlossen ist der Hauptsandstein (Wealden 3) . Es werden die Sedimenttexturen der Sohlbankfläche des ehemaligen Steinbruchs analysiert und interpretiert. Vorherrschende Schichtungstypen sind Wellenrippelschichtung und Flaserschichtung. Die Sedimente sind stark bioturbat. Auf mehreren freiliegenden Flächenniveaus der Sohlbank sind Rip- pelmarken zu beobachten, die systematisch vermessen wurden. Danach handelt es sich uro Wellenrippeln und untergeordnet um strömungsüberformte Wellenrippeln durch ablaufendes Wasser. Zahlreiche Merkmale zeigen wiederholtes Auftauchen und Trok- kenfallen an. Tonlagen kennzeichnen zeitweilige Stillwasserbedingungen. Ein ehemals verzweigtes Rinnensystem ist in Relikten erhalten und beweist ebenfalls einen wechselnden Wasserstand (ablaufendes Wasser). Sporadisch kam es im Zuge hochenergetischer Ereignisse zu einem schichtflutartigen Abfließen des Wassers. Eine reiche Ichnofauna ist zu beobachten. Wenige Spurentypen sind vorhanden, die Spurendichte ist jedoch sehr hoch. Es dominieren horizontale oder wenig geneigte Gestaltungswühlgefüge, vertikale Bauten kommen nur untergeordnet vor. Als häufigste Spurentypen treten Thalassinoides, Muensteria, Plano- lites und Pelecypodichnus auf. Die Größe der Ichnofossilien ist meist gering. Die Spuren bilden eine Ichnocoenose aus Ichnofossilien der Cruziana- und untergeordnet der Skolithos- Fazies. Bivalven belegen Brackwasser-Verhältnisse. Dies alles sind Merkmale eines lagunären Ablagerungsraumes, gelegen am Rand eines gezeitenarmen bzw. -losen Nebenmeeres (Niedersächsisches Becken) im Übergang von der fluviatilen in die litorale Fazies im rückwärtigen Bereich eines Barrierensystems. Wahrscheinlich spielte Wind eine entscheidende Rolle als Ursache für Wasserspiegelschwankungen. Die maximale Wassertiefe bei auflandigem Sturm hat vermutlich nicht mehr als 3 - 4 m betragen. Sonst war sie wahrscheinlich deutlich geringer und ermöglichte Dinosauriern ein Durchwaten des Gewässers, wie Fährten auf der Sohlfläche beweisen.

Correlação entre as propriedades mecânicas de materiais impermeabilizantes a base de elastômeros de poliuréia e poliuretano com o desempenho do sistema aplicado em lajes estruturais

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, Programa de Pós-graduação em Estruturas e Construção Civil, 2015.

Ciríaco de Cardoso e O burro do Sr. Alcaide : percursos de formação de um compositor de comédia musical no Portugal finissecular

O principal objetivo deste estudo foi compreender as etapas do percurso artístico do compositor portuense Ciríaco de Cardoso (1846 – 1900) e os discursos em torno de uma das suas obras mais célebres: O burro do Sr. Alcaide (1891). No primeiro capítulo procurou-se identificar e discutir os critérios que estiveram na base das opções profissionais tomadas por Ciríaco. O decurso da sua carreira leva a crer que possuía uma noção profunda das atividades que, no espaço lusófono, apresentavam maior potencial de aquisição quer de capital económico, quer de capital simbólico. É por isso que, mobilizando recursos das suas redes de sociabilidade, circula por instituições no Porto e em Lisboa mas, também, pelo lucrativo mercado teatral do Rio de Janeiro, assim como em Paris. Concentra-se no popular teatro musical – principal fonte de sustento – em paralelo com a atividade concertística e operática – forma de distinção atendendo à competitividade no mercado musico-teatral. Percebe também que a maximização do seu poder simbólico depende da legitimação alcançada pela sua associação às elites socioculturais locais, pelo que fomenta o estabelecimento de sociabilidades que se estendem inclusive às casas reais portuguesa e brasileira. Paradoxalmente, as edes mais próximas de Ciríaco estavam vinculadas a um idealismo republicano, relacionamento que exponencial proliferação de discursos dessa índole pelos media lusófonos (sobretudo a partir do tricentenário camoniano de 1880) e, por outro, pela aparente inexistência de registos que associem inequivocamente o artista ao ativismo republicano. Não obstante, é provável que Ciríaco de Cardoso tenha explorado o filão antimonárquico na programação da temporada de 1891 do Teatro da Avenida. O segundo capítulo explora a produção de O burro do Sr. Alcaide, através da análise da sua estrutura e das relações da obra com a realidade portuguesa da última década do século XIX. Embora respeite o modelo da opereta francesa, apresenta também características que poderão levar a que seja interpretada como transmissora de uma portugalidade idealizada, em linha com o nacionalismo português do último quartel do século. A ação decorre em Lisboa, cenário de interação entre personagens-tipo e caricaturas de personalidades concretas da elite sociopolítica portuguesa. Através de referências ao sebastianismo, satiriza-se o comportamento dessas elites, assim como as instituições da monarquia constitucional e a prevalência de uma visão messiânica dos governantes por parte da sociedade em geral. Faz-se a apologia da ruralidade através de tópicos musicais e de quadros onde se constrói uma imagem da música tradicional, correspondendo a uma idealização da nação – notada e enfatizada na receção pela crítica. Utiliza também outros tópicos pertencentes à paisagem sonora do público burguês, completando a expressão da urbanidade de um país onde essas duas realidades não eram ainda completamente dissociáveis. Contudo, ao não propor alterações efetivas à hierarquia da sociedade portuguesa finissecular, o desfecho da obra leva a concluir que esta terá consistido numa forma de propaganda o que, por um lado, explica o seu mediatismo e, por outro, vincula os seus autores – mais ou menos conscientes disso – às lutas políticas em curso aquando do ano da sua estreia.

Estudo da adição de argila expandida na formulação de concretos leves

Lightweight concrete has been the subject of several studies towards the development of new building materials. Emphasis has been given on the particle size effect and nature of aggregates used as raw materials. The present study includes an analysis of the materials that make this kind of concrete, analyzes of mechanical properties such as compressive and tensile strength, in addition to assessments of the interface concrete aggregate/matrix interface, porosity and absorption profile of chloride ions in lightweight concrete based on expanded clay. The experiments were carried out by molding cylindrical samples 100 mm in diameter and 200 mm in height. The dosage experiments were performed without additives or with the addition of minerals: (T1) 1: 2.01: 1.10: 0.78 (T2) 1: 2.00: 1.32 : 0.62 - (T3) 1 :1.93 :1.54: 0.47 (cement : sand : expanded clay 0500 : expanded clay 1506).The water to cement ratio was set to 0.43. Expanded clay minerals with different average particle sizes were used, i.e., 9.5 mm/0500 and 19 mm/1506. The larger aggregate was coated by a glassy layer, yielding lower water absorption characteristics to the concrete. The results showed that the use of light expanded clay aggregates is a technically interesting solution to the production of lightweight concrete for construction applications

Estudo do comportamento plástico, mecânico, microestrutural e térmico do concreto produzido com resíduo de porcelanato

Population growth experienced in major cities, allied to society s need of infra-structure, especially ones related to habitational demands, increases the consumption of construction materials. As a consequence, consumption of natural resources itself. Thus, due to this process, concrete is one of the most produced materials in civil construction. This is also due to the great diversity of its application, easiness in its execution and adequate mechanical performance, as well as low production costs. Following the same tendencies in construction development, the ceramic industry has intensified the production of porcelain ceramic tiles and floors. These are achieved by a fine finishing and receive polishing at the end of the fabrication process. This work researched the use of porcelain residues in polishing for the production of concrete. All of which; due to economical and environmental issues. This process aims to prove adequate destiny for this type of residue, due to environmental issues, incorporating it to the concrete itself; all of which provides economy in consumption of the materials that constitute concrete. Thus, the main characteristics of concrete were investigated through the inclusion of different concentration of the porcelain residue as additional trait element. The residue rates incorporated to the trait varied from 10% to 50% in relation to the cement mass, in the traits with plastic additives and without plastic additives. It is observed that the inclusion of porcelain residue produced a meaningful alteration in the consistency of fresh concrete. This residue has a fine granulometry and it considerably absorbed the water used in the concrete spreading, influencing the way this material is dealt with. Thus, the value of cement striking decreases with the increase of residues present in trait. The maximal incorporation of the residue was of 50%, massively, for the same factor water/initial cement. The use of residues in concrete results in an 40% increase in the compression resistance. It is also proportional to residue concentration of porcelain in the trait. The microstructure was also favored once porosity and concrete absorption decreases with the use of this residue. The parameters demonstrate the quality and durability of the concrete produced with this residue. The use of porcelain residue in concrete composition has not produced meaningful thermal behavior changes. Thermal conductivity, heat capacity and thermal diffusivity have been maintained basically constant

Estudo de revestimentos inorgânicos com inibidor de corrosão aplicado na superfície do concreto

The corrosive phenomenon on reinforced concrete structures is one of the most founded pathologies on the coastal area. With the objective to prevent the process development, or even, retard its beginning, it was studied the application of inorganic covering over concrete surfaces, after its cure, as well as, evaluate the efficiency of the covering applied on the concrete in reducing its porosity of concrete preventing the entrance of aggressive agents to preserve the integrity of the existing armor inside it, comparing the result obtained with the body-of-proof reference, that didn´t receive covering protection. On the concrete production it was used Portland Cement CP II 32, coarse aggregate, fine aggregate and water from the local distributive. Two types of covering were used, one resin based of silicon and solvent and other white cement based, selected sands and acrylic resin. The concrete mixture adopted was 1:1,5:2,5 (cement, fine aggregate, coarse aggregate) and 0.50 water/cement ratio. With the concrete on fresh state was made the experiment test to determinate the workability. On the hardened state was made the concrete resistance experiment, absorption of water and electrochemical experiments, through polarization curves. Also was held optical microscopy and Scanning Electron Microscopy experiments to analyze the layer of the covering applied to the concrete surface and the interface between the concrete and the layer. The obtained results shows that the covering applied to the concrete surface didn´t affect the resistance towards compression. On the absorption of water occurred a diminution of the percentage absorbed, improving the concrete development by making it more impermeable towards the entrance of aggressive agents. The electrochemical experiment results confirmed the water absorption results; the body-of-proof covered presented larger protection towards the development of corrosives process and retarded the evolution of the corrosive phenomenon

Avaliação de concretos reforçados por confinamento com manta de fibra de vidro estrutural e pré-impreganada

Due to the occurrence of diseases in the use of structural reinforcements in composites, with presentation of concrete blanket detachment, has been identified the need to evaluate the performance of concrete reinforced with glass fiber. This study aims to evaluate these concretes by means of testing methodologies, using concrete with low resistance with structural reinforcement for confinement by preimpregnated glass fiber and traditional fiberglass blanket. The first stage of work was the development of methodologies for analysis, opting for four types, such as the acoustic survey, strength to compressive, the pull-off and ultrasound. Next, tests were carried out using the four selected methodologies in 30 of proof-of-specimens by 5x10 cm, 15 were reinforced with the traditional fiberglass blanket with 5specimens exposed to test a marine environment of marine coastline of Natal-RN and 15 were reinforced with a pre-impregnated glass fiber blanket, as well as 5specimens exposed to a test environment of the marine coastline of Natal-RN. After conducting the acoustic survey, it has been verified a lack of delaminating and air bubbles in the samples, confirming the absence of gross shortcomings in the implementation of the ribs both the traditional fiberglass blanket and in the preimpregnated fiber glass blanket. After carrying out methods of pull-off and compressive strengthening test it was observed that the reinforced proof-bodies with pre-impregnated glass blanket showed maximum stresses higher than the traditional fiberglass blanket; consequently a greater grip with the formation of a smaller area of . fracture, unlike traditional glass mat, which showed lower maximum stresses, with a greater area of fracture. It was also found that the traditional fiberglass blanket presented detachment of blanket-concrete interface, unlike the pre-impregnated fiberglass blanket, which showed a better grip on the blanket-concrete interface. In the trial of ultrasound there was no presence of cracks in the blanket-concrete interface, yielding to both blankets good compactness of the concrete. At the end of this work, they were developed and proposed two methods of testing for evaluation of reinforced concrete structures with composites, for standardization, the acoustic survey and pull-off

Aplicación de residuos en la fabricación de morteros industriales

La presente Tesis Doctoral estudia el uso de la fracción fina de los residuos de construcción y demolición (RCD) en la fabricación de morteros de albañilería. El principal uso de los áridos reciclados de RCD es la construcción de rellenos o firmes de carreteras, aunque su uso como áridos para la fabricación de hormigones o morteros le daría un mayor valor añadido. A nivel internacional existen numerosos estudios sobre la utilización de la fracción gruesa de los áridos reciclados de RCD en la fabricación de hormigones. Sin embargo son escasos los trabajos llevados a cabo para valorizar la fracción fina. Actualmente en España la fracción fina de los áridos reciclados de RCD está infrautilizada y en la mayoría de los casos depositada sin uso en los vertederos de las Plantas de reciclaje. En este trabajo se han utilizado dos tipos de áridos reciclados, uno procedente de residuos de hormigón (FRCA) y otro de residuos mixtos de tabiquería con un alto porcentaje de ladrillo rojo cerámico (FMRA). Todos los materiales han sido caracterizados desde un punto de vista físico, químico y mineralógico para justificar el efecto de su incorporación a la fabricación de morteros industriales de albañilería. En una primera fase se estudiaron las propiedades del mortero fresco y endurecido fabricado con FRCA y cinco niveles de sustitución volumétrica de arena natural y FRCA: 0%, 5%, 10%, 20% y 40%.Se utilizó un cemento puzolánico tipo CEM-IV y se evaluaron las propiedades a corto y largo plazo de morteros de baja resistencia (M5) En una segunda fase, se utilizó un cemento tipo CEM-II y se fabricaron morteros de mayor resistencia (M-10) utilizando FRMA. En esta etapa se llevaron a cabo sustituciones de arena natural por arena reciclada de 0%, 25%, 50%, 75% y 100%. El residuo fue evaluado medioambientalmente mediante el test de conformidad antes y después de ser ligado con cemento (lixiviación). Los resultados fueron completados con estudios de durabilidad. Con el objetivo de completar los estudios anteriores, se llevó a cabo una tercera fase, donde se sustituyó hasta un 100% de arena natural por FRCA, utilizando un cemento tipo CEM-II para fabricar un mortero tipo M-10, dosificado de manera similar al empleado en la segunda fase de este trabajo. Como conclusión general de esta tesis, se puede decir que pueden admitirse tasas de sustitución de hasta un 50% de arena natural por árido reciclado en morteros industriales de albañilería para usos de interior sin que sus propiedades puedan verse afectadas significativamente. Los resultados obtenidos contribuyen a reducir la extracción de arena natural de canteras y ríos, minimizar el consumo de energía y emisiones de CO2, mitigar el calentamiento global y evitar el depósito en vertedero de la fracción fina de RCD.