Este trabalho investiga o potencial de utilização do entulho de construção e demolição, C&D, triturado na estação de reciclagem de entulhos de Ribeirão Preto - SP, como agregado graúdo no preparo de concretos de baixa e média resistências. A utilização da fração graúda, compreendida entre 4,8 mm < Dmáx < 19,0 mm, para substituir parcialmente ou totalmente o agregado graúdo graduado como brita 0 e brita 1 (NBR 7211/82), pode resultar em uma significativa economia na execução de componentes urbanos e habitacionais para construções de interesse social. O presente trabalho apresenta as características granulométricas e físicas, dos agregados reciclados, em comparação com as do agregado natural, usado como referência. Os resultados obtidos na substituição, parcial (50%) e total (100%), do agregado natural graduado como brita 1 e brita 0, utilizados na região de Ribeirão Preto, pelo reciclado graúdo da mesma faixa granulométrica, também são apresentados. A influência do agregado reciclado na perda do abatimento do concreto fresco e nas propriedades mecânicas do concreto endurecido, foram investigadas. Finalmente, realizou-se avaliação de desempenho à flexão em painéis leves de vedação, com a finalidade de se obter uma aplicação prática ao estudo desenvolvido. Concluiu-se, assim, pela viabilidade do emprego do agregado graúdo reciclado em substituição, total ou em parte, do equivalente natural em concretos estruturais de baixa resistência. / This dissertation researches the potential of the use of construction and demolition debris (C&D), crushed in the recycling station of Ribeirão Preto-SP, as coarse aggregate to make concrete of low and medium strenght. The use of coarse fraction, 4,8 mm < Dmax < 19,0 mm, substituting, partial or totally the natural aggregate, as recommended in NBR 7211/82, can result in a significant economy on the production of urban components and for social interest constructions. The present work presents the physical and granulometric characteristics of the recycled aggregate, comparing with the natural one, used as reference. Experimental results are showed and compared. The influence of recycled aggregate on the loss of the slump of fresh concrete and on the mechanical properties of harden concrete were analyzed. Finally, the flexural behavior of a model of panels was evaluated.

O emprego de concreto com resistência à compressão ultrapassando 100 MPa e o aumento do número de aplicações do concreto de alto desempenho em diferentes regiões do país mostra que há espaço para a consolidação desta tecnologia no meio técnico nacional. Contudo na medida em que se eleva a resistência à compressão dos concretos, os agregados passam a exercer um papel cada vez mais importante no comportamento global do material. A busca constante pelo entendimento preciso da influência das características do agregado nas propriedades do concreto tem despertado o interesse de diversos trabalhos em todo o mundo. O objetivo deste trabalho foi estudar a influência da resistência à compressão da rocha e a influência da dimensão máxima característica do agregado graúdo, nas propriedades mecânicas de concretos no estado endurecido produzidos com diferentes consumos de água (200, 160, 145, 130 e 115 litros de água). Para a produção do concreto utilizou-se como referência os princípios estabelecidos no método de dosagem proposto por Mehta e Aïtcin (1990). A metodologia baseou-se em ensaios laboratoriais e no uso de ferramentas estatísticas para validação dos resultados. Com base nesses resultados obtidos foram propostos modelos de previsão de comportamento. Em termos de resistência à compressão observou-se que a influência da dimensão máxima característica é maior para concretos produzidos com consumo de água menor. Quanto à resistência do agregado, os resultados obtidos neste trabalho negam a teoria da resistência potencial do agregado. A resistência à tração mostrou-se somente influenciada pelo consumo de água. O módulo de elasticidade do concreto, no entanto foi diretamente influenciado pela resistência da rocha. / The use of concrete with compressive strength of 100 MPa and the number of applications of high performance concrete in different regions of Brazil shows that this technology seeks to consolidate the national technical means. But to the extent that amounts to the compressive strength of concrete, aggregates start to exert an increasingly important role in the global behavior of the material. The objective was to study the influence of the compressive strength of rock and the influence of maximum size of coarse aggregate characteristic, the mechanical properties of concrete in hardened produced with different water consumption (200, 160, 145, 130 and 115 liters of water). To produce the dosage of concrete was used as a reference the principles of the determination method proposed by Mehta and Aïtcin (1990). The methodology is based on laboratory tests and the use of statistical tools to validate the results. Based on these results were proposed prediction models of behavior. In terms of compressive strength was observed that the influence of the characteristic maximum dimension is greater for concretes with lower water consumption. As the aggregate’s resistance, the results obtained in this work deny the theory of the potential resistance. The tensile strength was found to be only influenced consumption of water. The modulus of elasticity of the concrete, however it was influenced by the strength of the aggregates.

Concrete is one of the world’s most common construction materials and is composed of 70-80 % stone material. Today crushed stone is used as aggregate in concrete in order to replace natural aggregates due to strong environmental reasons. Stone crushing yields flaky material and in this thesis studies are made on the flaky particle shape and how it influence properties of concrete such as workability, rheology and strength. The concrete recipes used in this thesis have fixed values, the only variable is the flakiness of the crushed stone. Flakiness is varied between 0 %, 17 %, 50 %, and 100 % in turn for the individual size fractions 2-8 mm, 8-10 mm, 10–12.5 mm, and 12.5–16 mm. By using Swedish and European standards one determines flakiness index, packing factor, slump test, Thaulow tester, compression strength and flexural strength. The Bingham model is applied with the use of a viscometer to determine the concretes rheological properties such as plastic viscosity and yield stress. For the individual size fraction 12.5-16 mm a flow analysis is performed in an L-box to study how the particles are orientated with the flow direction, and how this influences the strength and crack length. Results show that the loose packing factor decreases with increased flakiness for all individual size fractions. Fractions 2-8 mm and 8-10 mm need a small increase in super plasticizer with increased flakiness to achieve 200 mm slump. The larger individual size fractions do not show any increase in super plasticizer regarding this matter. The Thaulow tester indicates constant values with increased flakiness for all individual size fractions except 2-8 mm were a weak increase is observed. Values of the plastic viscosity are indicated unchanged as the flakiness index is increased for all individual size fractions except 2-8 mm that slightly increase for 100 % flakiness. The yield stress behaves unchanged with increased flakiness for all individual size fractions except 12.5-16 mm which significantly decrease for 100 % flakiness. When the concrete flows in the L-box an image analysis concludes that the larger amounts of flaky particles are orientated with the flow direction. The crack length increases with higher flakiness for fraction 12.5-16 mm but this does not lead to an increase in strength. Flexural strength increase with higher flakiness, this is clearly observed for the two largest individual size fractions. Compressive strength is indicated to be independent of flakiness and is approximately constant for all individual size fractions except individual size fraction 12.5-16 mm that indicates an increase. High flakiness on cone crushed granite rock in size fraction 8-16 mm from the bedrock in Enhörna is not regarded as disadvantageous for concrete manufacturing, as it shows good values in workability, rheology and strength. / Betong är ett av världens vanligaste byggmaterial och består av ungefär 70-80 % stenmaterial. Idag används krossten som ballast i betong för att ersätta naturgrus av starka miljöskäl. Stenkrossning ger upphov till flisigt material och i detta arbete studeras den flisiga kornformen och hur den påverkar betongens egenskaper inom arbetbarhet, reologi och hållfasthet. Blandningsreceptet har fixerade värden och den enda variabeln som varierar i arbetet är flisigheten på krosstenen. Flisigheten varieras mellan 0 %, 17 %, 50 % och 100 % i tur och ordning för delfraktionerna 2-8 mm, 8-10 mm, 10–12.5 mm, och 12.5–16 mm. Genom att använda svenska och europeiska standarder bestäms flisighetsindex, packningsindex, sättmått, omformningstal, tryckhållfasthet och böjdraghållfasthet. Bingham modellen tillämpas för att med hjälp av en viskometer bestämma betongens reologiska egenskaper som plastisk viskositet och flytgränsspänning. För delfraktionen 12.5-16 mm utförs även flödesanalys med hjälp av en L-låda för att studera hur partiklar orienterar sig med flödesriktningen, och hur detta påverkar hållfastheten och spricklängden. Resultat visar att den lösa packningsgraden sjunker med ökad flisighet för samtliga delfraktioner. Fraktionerna 2-8 mm och 8-10 mm kräver en liten ökning av plasticerarmängden med ökad flisighet för att uppnå sättmått 200 mm. De större delfraktionerna visar dock ingen ökning av plasticerarmängd i detta avseende. Omformningstalet är i princip konstant med ökad flisighet för samtliga fraktioner förutom för 2-8 mm fraktionen där en svag ökning kan dokumenteras. Den plastiska viskositeten indikeras oförändrad då flisighetsindex ökar för samtliga delfraktioner förutom 8-10 mm fraktionen som ökar en aning vid 100 % flisighet. Flytgränsspänningen beter sig konstant med ökad flisighet för samtliga delfraktioner förutom 12.5-16 mm som signifikant sjunker för 100 % flisighet. När betongen flyter i L-lådan dras slutsatsen från bildanalys att den största delen flisiga partiklar orienterar sig med flödesriktningen. Spricklängden ökar med större flisighet för fraktionen 12.5-16 mm men detta visar ingen ökning i hållfastheten. Böjdraghållfastheten blir högre med ökad flisighet, denna trend visas tydligast av de två största delfraktionerna Tryckhållfastheten kan indikeras vara oberoende av flisighet och är ungefär konstant för samtliga delfraktioner förutom delfraktion 12.5-16 mm som indikerar en ökning. Hög flisighet på konkrossad granitsten fraktion 8-16 mm från bergtäkten i Enhörna anses inte vara ogynnsam för betongtillverkningen, då den ger goda värden på arbetbarhet, reologi och hållfasthet.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-02-05T12:26:48Z No. of bitstreams: 1 JOÃO RAFAEL SEVERO NOGUEIRA_ .pdf: 2326836 bytes, checksum: feff4e1efd0b8efb7dec079f29659d53 (MD5) / Made available in DSpace on 2016-02-05T12:26:48Z (GMT). No. of bitstreams: 1 JOÃO RAFAEL SEVERO NOGUEIRA_ .pdf: 2326836 bytes, checksum: feff4e1efd0b8efb7dec079f29659d53 (MD5) Previous issue date: 2015-06-19 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul / A reciclagem dos resíduos de construção e demolição (RCD) classe A é incentivada e a viabilidade do seu emprego como agregado alternativo em concretos e argamassas já vem sendo estudada por diversos autores. A fração de concreto do RCD é indicada como a mais viável para o emprego como agregado na produção de concretos, pois apresentam propriedades mecânicas mais elevadas que outras frações do RCD classe A, e características próximas à matriz na qual são inseridos. Porém, apresentam-se mais porosos e possuem propriedades mecânicas inferiores aos agregados convencionais. A porosidade do agregado de concreto reciclado influencia na sua absorção de água, o que geralmente altera a demanda de água da nova mistura, podendo desta forma, trazer prejuízos ao novo concreto, principalmente no estado fresco e na durabilidade. Muitas pesquisas têm incorporado o Agregado Graúdo Reciclado de Concreto (AGRC) ao concreto no início da mistura, o que faz com que o mesmo tenha maior tempo para absorver a água de amassamento durante o preparo e manipulação, trazendo prejuízos a consistência do concreto. Um dos métodos para mitigar este efeito é o seu emprego saturado ou parcialmente saturado com água, o que introduz uma etapa prévia de preparação do AGRC na produção do concreto. A presente pesquisa tem por objetivo comparar dois diferentes métodos de incorporação do AGRC na mistura de concreto, com o intuito de mitigar os efeitos da sua maior absorção de água. Alternativamente ao método tradicional, foi avaliada neste estudo a incorporação do AGRC seco ao final da mistura. Para avaliar estes concretos, foram realizados os ensaios de abatimento de tronco de cone (slump), resistividade elétrica no estado fresco, resistência à compressão, absorção de água por capilaridade e resistividade elétrica no estado endurecido. A consistência do concreto sofre menos influência do AGRC quando ele é incorporado no final da mistura. No entanto, a resistividade no estado fresco não aponta diferenças significativas entre os dois métodos. Já no estado endurecido, percebe-se que, por absorver água de amassamento, e com isso reduzir a relação a/c efetiva, a incorporação do AGRC na primeira etapa da mistura traz resultados de resistência à compressão, em alguns traços, superiores ao concreto de referência. / The recycled concrete aggregate (RCA) have been widely studied and the results have been showed that its employ in partial replacement can be feasible. This recycled aggregate is more viable to use in concrete than those recycled from mixed construction and demolition waste. However, the RCA has a higher porosity than natural aggregate and sometimes their mechanical resistance is less than the new concrete resistance. The higher porosity leads the RCA to absorb the mixing water of new concrete and to reduce the concrete slump. To avoid these problems the consequences are an increase on the water demand and on the cement consumption, in order to maintain the water/binder ratio. There are some ways to mitigate these problems like as to add water to the mixture, use the RCA pre saturated, cover the RCA surface with resins, use carbonated RCA. Some researchers proposed different concrete mix methods to produce concrete with RCA with some good results. The aim of this research is to evaluate two methods of mixing concrete with recycled concrete aggregate and their influence in fresh and hardened concrete properties. Usually the RCA is added to the mixture in the same time as the natural aggregate. This practice put the RCA in contact with the fresh mixing for a large period time and lead to absorb a higher amount of water. In consequence, there is a great loss in concrete slump, but this can bring an increment in the concrete resistance. In alternative, this work proposed the adding of RCA in the end of the mixture, evaluating the influence of the two methods the properties of fresh concrete and hardened concrete. The loss in concrete slump is lower when the RCA is introduced at the end of the mixture. However there is no significant difference in the electrical resistivity of fresh concrete. For hardened concrete, the best results were from concretes where the RCA was added at the end of the mixture.

L’estimation des déformations différées, en particulier dans le cas des Béton à Hautes Performances (BHP) destinés aux ouvrages d’art, est primordiale pour prédire les flèches, les redistributions des contraintes dans les structures hyperstatiques et les pertes de précontrainte dans des éléments en béton précontraint. L’expérience montre néanmoins une dispersion certaine des valeurs de déformations instantanées et différées mesurées et des écarts non négligeables avec les valeurs calculées selon les règlements de dimensionnement.L’objectif de ce travail de thèse est de s’intéresser à un paramètre non pris en compte dans les règlements qui pourrait être à l’origine des imprécisions de leurs prédictions : le gravillon. Le programme expérimental s’articulera autour d’une étude comparative des comportements mécaniques instantanés et différés sans charge, retrait, et sous charge, fluage, de six BHP de même formulation de base (rapport E/L, volume de pâte), se différenciant principalement par le type de gravillon. A partir de cette base de données complétée par des analyses mécaniques et physico-chimiques sur les granulats, des paramètres influents liés au type de gravillon incorporé ont été détectés. Des comparaisons avec les estimations des modèles actuels tels que l'Eurocode 2 ont également été réalisées et ont montré des différences notables avec les valeurs expérimentales.Des analyses microstructurales ont été menées afin d'identifier l'état de la microstructure et du réseau poreux des matériaux, plus particulièrement à l'interface pâte-granulat (Interfacial Transition Zone ITZ). L'étude de l’ensemble des résultats a permis d’établir des corrélations entre le comportement mécanique et les analyses microstructurales. Une synthèse des données récoltées durant ce travail de recherche montre que le gravillon a une influence non négligeable sur les comportements mécaniques instantané et différé à travers différents paramètres de degré d'influence variable / The prediction of the time-dependent deformations, particularly in the case of high performance concrete (HPC) envisioned for bridges is essential for predicting the deflections, the stress distribution in statically indeterminate structures and the loss of pre-stressing force in elements of pre-stressed concrete. However, the experience shows a certain dispersion of values of instantaneous and delayed deformations measured and some significant differences with the values calculated using the building codes.The objective of the present thesis work focuses on the coarse aggregate parameter which is not taken into account in building codes, which could causes the inaccuracies of their predictions. The experimental program includes a comparative study of the mechanical behaviours (instantaneous and delayed), shrinkage, creep, of six HPC with the same basic formulation (water cement ratio, volume of paste), differing principally in the type of coarse aggregate. From this database and thanks to the mechanical and physicochemical analyses of the aggregates, some influent parameters related to the type of the coarse aggregate were detected. The comparisons with estimations of standard models such as Eurocode 2 were also performed and showed significant differences with the experimental values.Micro-structural analyses were carried out in order to identify the state of the microstructure and the porosity of materials, more particularly at the interface between the cement paste and the coarse aggregate (Interfacial Transition Zones ITZ). The study of the results made it possible to establish correlations between the mechanical behaviour and the micro-structural analyses. A synthesis of the data collected during this research work shows that the coarse aggregate has a considerable influence on the mechanical behaviours (instantaneous and delayed) through various parameters from variable degree of influence

Master of Science / Department of Civil Engineering / Stacey Kulesza / In Kansas, mechanically stabilized earth (MSE) retaining walls are typically backfilled with coarse aggregate. Current backfill material testing procedures used by the Kansas Department of Transportation (KDOT) utilize on-site observations for construction quality assurance and the American Association of State Highway and Transportation Officials standard T 288-12 (“Standard Method of Test for Determining Minimum Laboratory Soil Resistivity”). AASHTO T 288-12 is designed to test a soil sample’s electrical resistivity (ER) that correlates to its corrosion potential. However, the test, based on material passing through a No. 10 sieve, is inappropriate for coarse aggregate typically used by KDOT as the aggregate will be retained on a No. 10 sieve and potentially leads to over-conservative designs. However, ER imaging provides a two-dimensional (2D) profile of bulk ER of backfill material, thereby yielding more information regarding backfill uniformity compared to traditional sampling. The objective of this study was to characterize bulk ER of in-place MSE wall backfill aggregate. In this study, MSE walls selected by KDOT were tested using ER imaging during construction to determine bulk ER of the backfill. Variations within backfill ER may be a result of varying aggregate material, inclusions of fines, thoroughness of compaction, and the presence of water. ER imaging was used on five walls: four MSE walls and one gravity retaining wall that contained no reinforcement. One MSE wall contained metal reinforcement, while the other four walls contained geosynthetic. The ER imaging field method produced a 2D profile that depicted ER uniformity for bulk analysis. A post processing algorithm was generated to remove the subjective nature of the ER imaging results. The program determines the bulk ER based upon the ER imaging results. These results indicate that the laboratory analysis of AASHTO T 288-12 under-estimates the bulk ER of in-situ backfill material. Identification of a material’s bulk ER will help characterize the ER of aggregates in a complementary KDOT project. Results of this study will be used to recommend an in-situ test method for aggregate used by KDOT.

En los últimos años existe una demanda cada vez más creciente de infraestructura; actualmente en el Perú el sector construcción ha ido en constante crecimiento; sin embargo, es uno de los más contaminantes debido a la fabricación del concreto y sus componentes, ya que la industria concretera es responsable de la extracción de recursos no renovables; siendo el concreto el material fundamental para los diferentes tipos de proyectos en vías de desarrollo. Frente a este entorno, se propone como alternativa sostenible el uso de residuos de demolición, es decir agregado grueso de concreto reciclado en reemplazo del agregado grueso natural; sin embargo, en investigaciones anteriores el reemplazo de este, presenta una disminución en la resistencia a la compresión y flexión de 10% - 25% y 23.7% respectivamente. Por esta razón, se seleccionó el vidrio triturado proveniente del reciclado de botellas incoloras, este es un material eco amigable y de características que contribuyen en la resistencia del concreto. En consecuencia, se propone el uso de estos agregados reciclados en reemplazo total y parcial del agregado grueso y fino respectivamente. Los resultados de estos ensayos indicaron un aumento en las propiedades mecanicas del concreto y el porcentaje óptimo de reemplazo de vidrio triturado es 20%, en donde se obtuvo un incremento de 12.33% en la Resistencia a la compresión, 17.19% en la Resistencia a la flexion y 1.98% en la Resistencia a la tracción. / In recent years there is an increasingly growing demand for infrastructure; Currently in Peru the construction sector has been in constant growth; However, it is one of the most polluting due to the manufacture of concrete and its components, since the concrete industry is responsible for the extraction of non-renewable resources; concrete being the fundamental material for the different types of projects under development. Faced with this environment, the use of demolition waste is proposed as a sustainable alternative, that is, coarse aggregate of recycled concrete to replace the natural coarse aggregate; However, in previous research, its replacement shows a decrease in compressive and flexural strength of 10% -25% and 23.7%, respectively. For this reason, the crushed glass from the recycling of colorless bottles was selected since it is an eco-friendly material and features that contribute to the strength of the concrete. Consequently, the use of these recycled aggregates is proposed in total and partial replacement of the coarse and fine aggregate respectively. The results of these tests indicated an increase in the mechanical properties of the concrete and the optimum percentage of replacement of crushed glass is 20%, where an increase of 12.33% in Compressive Strength, 17.19% in Resistance to Compression was obtained. flexion and 1.98% in tensile strength. / Tesis

The diploma thesis is focused on the comparison of the influence coarse-grained aggragate on the properties af asphalt concrete. The theoretical part describes issue of production and usage of asphalt mixtures. The practical part evaluates multiple types of asphalt mixtures and describing their properties. Stiffness by a two-point bending test, a wheel tracking test and low-temperature cracking and properties by uniaxial tension test were used to evaluate the properties of the mixtures.