Ce travail se situe dans le cadre du projet ANR VBD ECOREB qui œuvre avec le projet national PN RECYBETON à la levée des verrous technologiques propres à l’utilisation des granulats recyclés en vue de la formulation des bétons de structure.Pour cette étude six bétons de granulats recyclés correspondant à deux classes de résistance C25/30 et C35/40 et à une classe de consistance S4 sont élaborés. Ces formulations, définies dans le cadre du PN RECYBETON, sont conçues à partir de deux formulations de référence en substituant partiellement ou complètement les granulats naturels par des matériaux issus du recyclage des bétons. Un programme expérimental a été réalisé pour déterminer les propriétés du béton à l’état frais et à l’état durci. Les résultats des essais mécaniques montrent que pour la même classe de résistance à la compression, l’incorporation des granulats recyclés dans le béton induit une diminution de la résistance à la traction et du module d'élasticité .aussi bien qu’une augmentation de la déformation au pic et de la déformation ultime. Sous compression cyclique du type charge-décharge, l’endommagement au pic de contrainte augmente lorsque le taux de substitution est important alors que la vitesse d’endommagement devient plus faible. La campagne d’essais du fluage menée sur des poutres chargées en flexion trois points indique que la cinétique du fluage est influencée par la présence des granulats recyclés et elle est d’autant plus accélérée que le taux de remplacement est important.Les résultats expérimentaux de cette étude ainsi qu’un nombre important des résultats rapportés dans les références bibliographiques ont permis d’évaluer la validité des relations analytiques développées pour prédire les propriétés mécaniques du béton des granulats naturels en vue de leur utilisation pour le béton des granulats recyclés. On montre que ces expressions nécessitent la connaissance de la résistance moyenne à la compression, fcm aussi bien qu’un coefficient qui tient compte de l’effet des granulats recyclés. La comparaison entre les courbes contrainte-déformation obtenues dans le cadre de cette thèse et certains modèles montre, qu’avec les modifications proposées, ils décrivent d’une manière satisfaisante le comportement jusqu’à la rupture. / This work is part of the ANR VBD ECOREB which aims with the project PN RECYBETON to remove the technological locks for the use of recycled aggregates for the formulation of structural concretes.For this study, six concretes of recycled aggregates corresponding to two classes of compressive strength C25 / 30 and C35 / 40 and S4 class of workability are developed. These mixtures, defined in the framework of the PN RECYBETON, are derived from two reference formulations by substituting partially or completely the natural aggregates with materials resulting from the recycling of concretes. An experimental program was carried out to determine the properties of concrete in fresh state and hardened state. The results of mechanical tests show that for the same class of compressive strength, the incorporation of recycled aggregates into the concrete induces a decrease in the tensile strength and the elastic modulus as well as an increase in the peak and ultimate strains. Under loading-unloading compression, the damage at the peak stress increases when the substitution rate is high while the damage rate becomes lower The creep tests carried out on beams loaded under three-point bending indicate that creep kinetics are influenced by the presence of recycled aggregates and is accelerated as the replacement rate is important.The experimental results of the present study together with an extensive number of results reported in the literature have allowed evaluating the current relationships used for predicting mechanical properties of recycled concrete aggregates (RAC). The validity of many analytical expressions of the stress-strain relationship has been also studied and the effect of replacement ratio was taken into account. It was pointed out that design codes relationships dedicated to assess the mechanical properties and the stress-strain compressive curve of natural aggregates concretes (NAC) are not adequate to predict the behavior of recycled aggregates concrete (RAC). It is established that these properties are related to fcm and to a parameter, which takes into account the effect of the recycled aggregates. The comparison between the stress-strain curves obtained in this thesis and some models shows that, with the proposed modifications, these models satisfactorily describe the behavior up to failure.

El presente trabajo de investigación para optar el título en Ingeniería Civil, con énfasis en la rama de construcción, tuvo como finalidad evaluar y comparar el comportamiento del concreto con diferentes proporciones de sustitución de agregado grueso natural (AN) por agregados de concreto reciclado (ACR) con el fin obtener un diseño de concreto que permita la disminucion y uso de agregados naturales, y asi disminuir la depredacion de canteras. El comportamiento se evaluó mediante el análisis de las propiedades mecánicas y durabilidad de los tipos de mezclas realizados con el objetivo de obtener una proporción de sustitución óptima de AN por ACR para que las propiedades se encuentren dentro de los parámetros que indican las normas. Por otro lado, se realizó un modelo de una estructura aporticada para hacer una Evaluación de Impacto Ambiental mediante el uso de la metodología Life Cycle Assessment (LCA) en el programa Athena y, posteriormente, se comparó los resultados obtenidos en dicho programa. / The present research work to choose the degree in Civil Engineering, with emphasis in the construction branch, had the purpose of evaluating and comparing the behavior of concrete with different proportions of substitution of natural coarse aggregate (AN) by aggregates of recycled concrete (ACR ) in order to obtain a concrete design that allows the reduction and use of natural aggregates, and thus reduce the depredation of quarries. The behavior was evaluated by analyzing the mechanical properties and durability of the types of mixtures made with the objective of obtaining an optimal substitution ratio of AN by ACR so that the properties are within the parameters indicated by the standards. On the other hand, a model of a contributed structure was made to make an Environmental Impact Assessment by using the Life Cycle Assessment (LCA) methodology in the Athena program and, subsequently, the results obtained in said program were compared. / Tesis

En la actualidad las cantidades de residuos han incrementado con el pasar de los años, convirtiéndose en una amenaza grave para el medio ambiente. Esto ha generado que reciba mayor atención por las autoridades e investigadores a nivel global, proponiendo usos respetuosos con el medio ambiente de estos residuos, los cuales han ido desarrollando y mejorando en los últimos años. Este estudio profundiza en el posible uso del residuo de vidrio plano como una solución sostenible, al ser adicionados en el concreto. Para esto, se hicieron diseños de mezcla con diferentes cantidades de vidrio pulverizado y se realizaron comparaciones para identificar el efecto en las propiedades del concreto mediante ensayos de asentamiento, resistencia a la compresión y resistencia a la compresión en condiciones de ataque por sulfatos. Los resultados muestran que, para dichas pruebas, la adición de vidrio pulverizado favorece a las características de sus propiedades, presentando además un ahorro económico. / At present the amounts of waste have increased over the years, turning into a serious threat to the environment. This has generated greater attention by authorities and researchers around the world, proposing environmentally friendly uses of these residues, which have been developing and improving in recent years. This study delves into the possible use of pulverized flat glass waste as a sustainable solution, when added to concrete. For this, mixing designs were made with different amounts of glass powder and comparisons were made to identify the effect on the properties of the concrete by slump tests, compressive strength and compressive strength in sulfate attack conditions. The results show that for these tests, the addition of glass powder favors the characteristics of its properties, while presenting an economic saving. / Tesis

<p dir="ltr">The construction industry is one of the largest contributors to carbon emissions, abiotic depletion of natural resources, and waste generation due to the vast quantity of concrete produced. Concrete’s main components have a significant environmental impact. The manufacturing of cement is responsible for 8% of global carbon emissions. In 2019, over 45 billion tons of aggregates were produced. Furthermore, the production of concrete generated over 600,000 tons of concrete waste in 2018.</p><p dir="ltr">Conversely, vegetation consumes 30% of the global carbon dioxide emissions. Recent studies indicated that cryptogamic species, and in particular moss, present a CO₂ uptake of 6.43 billion metric tons more than bare soil. Cryptogamic covers, such as moss and other CO₂ sequestering organisms, are key for the global cycles of carbon and nitrogen. By promoting the growth of living cryptogamic organisms in concrete building facades and roofs, the carbon footprint of concrete can greatly decrease, potentially achieving sub-zero carbon footprint. To attain this solution, cementitious composites must be designed to have an improved bio-receptivity, defined as a material's ability to be colonized by living organisms, or as a substrate to grow living organisms.</p><p dir="ltr">Previous studies show that the bio-receptivity of cementitious composites depends on a material’s acidity and ability to capture and retain water. Yet, the inter-relationship between these properties and bio-receptivity is currently not well understood. Additionally, existing methods to achieve enhanced bio-receptivity in cementitious composites in terms of are often either expensive or counterproductive in terms of sustainability.</p><p dir="ltr">This thesis aims to investigate and develop new methods to create ultra-sustainable composites with enhanced bio-receptivity and low abiotic depletion of natural resources. Additionally, this thesis aims to understand the importance, inter-relationship, and influence of the acidity and water storage properties of cementitious composites on their bio-receptivity.</p><p dir="ltr">The first portion of this thesis is focused on proposing a new method to enhance bio-receptivity of precast cementitious composites elements through accelerated CO₂ exposure treatment and elucidating the function of recycled concrete aggregate use to create ultra-sustainable composites with enhanced bio-receptivity and low abiotic depletion of natural resources. Thus, this study simultaneously tackles the reduction of waste generation and abiotic depletion of natural resources, as well as the promotion of bio-receptivity while reducing the net carbon footprint of the cementitious composites. Results suggested that the proposed accelerated CO₂ exposure treatment enhanced the bio-receptivity of mortars, especially in mortars with RCFA. The combined effect of the RCFA’s high porosity plus the effect of accelerated CO₂ exposures decrease on pH drastically enhanced the ability of promoting moss growth on mortars, enabling the production of low carbon bio-receptive cementitious material with a sub-zero abiotic depletion of natural resources.</p><p dir="ltr">The purpose of the second portion of this thesis was focused on understanding of the inter-related role of the mortar’s porosity, water absorption, and surface pH on the bio-receptivity of cementitious composites. This portion of this thesis also focused on creating a predictive model of bio-receptivity of mortars as a function of water storage properties and surface pH. By conducting this study, the extent of importance of the water storage properties and surface pH on bio-receptivity can be determined. Results suggested that w/c ratio heavily influences the bio-receptivity of mortar, in which a higher w/c ratio increases bulk porosity, water absorption, and decreases the average surface pH. The use of accelerated CO₂ exposure improved bio-receptivity due to and decrease in average surface pH. Additionally, the combined effects of high w/c ratio and accelerated exposure CO₂ exhibited even greater improvements in bio-receptivity. Furthermore, the increase in w/c ratio resulted in the mitigation of accelerated CO₂ exposure adverse effects on bulk porosity and absorption. The developed bio-receptive predictive model successfully predicts the bio-receptivity of mortars as a function of the average surface pH and water absorption. This bio-receptivity prediction model provides us with an instrument to assist in engineering concretes with a target bio-receptivity. The results of this study also show that, while previous literature indicated a maximum pH of 5.0-5.5 to produce a bio-receptive cementitious composite, the pH threshold to obtain a bio-receptive cementitious composite depends on other factors such as porosity of the material, and it is possible to create bio-receptive concretes with a surface pH of 6.2-8.3.</p><p dir="ltr">This research will contribute to creating target-by-design living-engineered concrete facades that can capture CO₂ while reducing the consumption of natural resources.</p>

The use of recycled concrete aggregates (RCA) has gained increased attention in the past few decades as an alternative to decrease the carbon footprint of concrete construction. Yet, most of the research performed so far demonstrates that RCA concrete displays inferior performance in the fresh and hardened states when compared to conventional concrete (CC). The latter is believed due to the fact that very often the different microstructure of RCA is not accounted for while the mix-proportioning of RCA concrete. Recently, a number of mix-design procedures accounting for RCA microstructure have been proposed. Amongst them, the Equivalent Volume (EV) method seems to be quite promising. The EV method may proportion RCA concrete made of coarse (CRCA) or fine (FRCA) RCA and is based on a companion CC. Previous research has demonstrated that the fresh and hardened properties of EV mix-designed CRCA are suitable for structural applications. Yet, very few research, analysis and quantification have been conducted on the fresh behaviour of EV mix- proportioned FRCA concrete. This work presents a comprehensive study on the rheological behaviour of EV mix-designed CRCA and FRCA concrete presenting distinct features (i.e. inner qualities, mineralogy, fabrication process, etc.) through the use of a planetary rheometer (IBB). Results show that the EV is capable of proportioning low embodied energy CRCA and FRCA concrete with shear thinning profiles. The latter suggests that these mixtures are suitable for applications under high torque regimes such as vibrated or pumped concrete.

L'introduction de granulats de béton recyclé (i.e. granulats produits à partir des gravats issus de la démolition d'ouvrages en béton obsolètes) dans les formulations de béton impacte de manière significative le comportement structurel des éléments en béton armé. Ce travail est consacré à l'étude de l'influence des granulats de béton recyclé sur l'adhérence armature-béton. Dans un premier temps, un modèle analytique de l'adhérence armature-béton est développé. L'originalité du modèle proposé réside dans le nombre limité de paramètres physiques sur lesquels il est fondé. Ces paramètres physiques sont ensuite déterminés expérimentalement via la réalisation d'une campagne d'essais d'arrachement. Trois types de bétons, dont deux bétons de granulats de béton recyclé, sont étudiés. Le suivi de l'arrachement de l'armature est complété par des mesures acoustiques permettant d'obtenir des informations provenant du coeur de l'échantillon, où l'armature se trouve. / The use of recycled concrete aggregate (i.e. aggregate produced from concrete demolition rubble) has a significant impact on the mechanical behavior of reinforced concrete members. This work focuses on the influence of recycled concrete aggregate on rebar-concrete bond. First, an analytical madel of the rebar-concrete bond is developed. The original feature of this modellies in the limited number of non-free physically-based parameters on which it is based. These parameters are then experimentally determined through a pull out test campaign. Three types of concrete, including two recycled aggregate concretes, are studied. Pull-out test monitoring is completed by acoustic measurements in order to obtain data from inside the concrete bulk, where the reinforcing bar is located.

Submitted by Vanessa Nunes (vnunes@unisinos.br) on 2015-03-20T15:04:23Z No. of bitstreams: 1 VinicioCecconello.pdf: 2409731 bytes, checksum: fd354892ead7d9cb57266673c9111acd (MD5) / Made available in DSpace on 2015-03-20T15:04:23Z (GMT). No. of bitstreams: 1 VinicioCecconello.pdf: 2409731 bytes, checksum: fd354892ead7d9cb57266673c9111acd (MD5) Previous issue date: 2013-08-16 / FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul / FINEP - Financiadora de Estudos e Projetos / A incorporação de agregados reciclados de concreto, em novos concretos é uma alternativa de reduzir os impactos ambientais relacionados a este material. No entanto, seu emprego pode aumentar a porosidade do concreto e alterar suas propriedades. Neste contexto a de cinza de casca de arroz pode trazer melhorias nas propriedades dos concretos, e principalmente quanto às propriedades mecânicas e a retração. O presente trabalho tem como objetivo a análise da retração, propondo um modelo matemático para este fenômeno, em concreto com associação de agregados reciclados de concreto e cinza da casca de arroz. Foram produzidos concretos com: 25% e 50% de agregado reciclado em substituição ao agregado natural; 0%, 10% e 20% de substituição de cimento por cinza de casca de arroz; e relações água/aglomerante iguais a 0,42, 0,53 e 0,64. A resistência à compressão foi analisada aos 7, 28, 63, 91 e 112 dias, os ensaios de resistência à tração, taxa de absorção, porosidade capilar e porosidade total foram analisadas aos 28 dias já os ensaios de retração foram analisados ao 1, 4, 7, 14, 28, 63, 91 e 112 dias. Os resultados obtidos indicam grande interação entre a cinza de casca de arroz e o agregado reciclado de concreto, esta interação fica ainda mais evidenciada no momento em que é introduzido junto à mistura 20% de cinza de casca de arroz, tanto no modelo apresentado para análise da retração como nas demais propriedades analisadas. / The incorporation of recycled concrete aggregate in new concrete is an alternative to reduce the environmental impacts related to this material. However, their use may increase concrete porosity and change their properties. In this context the rice husk ash can improve the properties of concrete, mainly mechanical properties and shrinkage. This work aims to analyze the concrete shrinkage, proposing a mathematical model for this phenomenon for concretes with the association of recycled concrete aggregates and rice husk ash. Concretes were produced with 25% and 50% of recycled concrete aggregate replacing natural aggregate; 0%, 10% and 20% replacement of cement by rice husk ash, and 0.42, 0.53 and 0.64 water/binder ratios. The compressive strength was a nalyzed at 7, 28, 63, 91 and 112 days. Tensile tests, absorption rate, capillary porosity and total porosity were analyzed at 28 days of age; shrinkage was analyzed at 1, 4, 7, 14, 28, 63, 91 and 112 days of age. The obtained data indicate strong interaction between rice husk ash and recycled concrete aggregate, this interaction is even more evident when it is used 20% rice husk ash, for all properties studied.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-05-29T18:30:06Z No. of bitstreams: 1 Ângelo Cezar Fumagalli Rostirola.pdf: 4315210 bytes, checksum: ff48e5f928774ac2545c3ae6774d5dcf (MD5) / Made available in DSpace on 2015-05-29T18:30:06Z (GMT). No. of bitstreams: 1 Ângelo Cezar Fumagalli Rostirola.pdf: 4315210 bytes, checksum: ff48e5f928774ac2545c3ae6774d5dcf (MD5) Previous issue date: 2013-10-24 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / SINDUSCON-NH - Sindicato das Indústrias da Construção Civil Novo Hamburgo / A construção civil atualmente é a indústria com maior crescimento no Brasil, fomentada por financiamentos e programas do governo federal. É também uma das indústrias que mais consome recursos naturais e energia, além de ser a principal geradora de resíduos sólidos urbanos. Grande parcela destes recursos naturais consumidos pela construção é formada pelos agregados. Uma alternativa econômica e ambientalmente correta, para diminuir a extração deste material, é a sua substituição por algum outro material, se possível por um resíduo, como apontam várias pesquisas. A busca por materiais e produtos ecologicamente corretos está em uma crescente, assim como os estudos para a reciclagem de diversos resíduos. A união entre produtos que consomem um volume menor de matéria-prima com o emprego de resíduos na sua produção parece uma saída viável para um desenvolvimento mais sustentável. Artefatos para a construção civil produzidos com concreto celular autoclavado (CCA) utilizam até quatro vezes menos materiais quando comparados a produtos com características semelhantes, produzidos com concreto convencional, cerâmico, entre outros. Além do menor consumo dos materiais constituintes, o concreto celular possui outras propriedades interessantes, como: suficiente resistência à compressão; isolamento térmico e acústico; baixa densidade; resistência ao fogo. Esta pesquisa teve como objetivo principal avaliar a influência da substituição parcial do agregado natural por agregado reciclado de concreto (ARC) na produção de concreto celular autoclavado. Após realização de estudos-piloto, optou-se pelo emprego da proporção de Cimento e Agregado Natural (AN) de 67% e 33% e sobre estes 0,45% de Cal e 0,3% de Alumínio com relação água/sólidos igual a 0,32. Foram empregados Cimento Portland CP-V ARI, Cal calcítica, areia natural e agregado fino reciclado de concreto, em teores de 0%, 25% e 50%. A dimensão máxima do agregado empregado na produção de CCA é de 150 µm. A cura foi realizada em autoclave após um tempo de espera de 24 horas a partir do início da mistura, por um período de 6 horas. Foram avaliadas a resistência à compressão, a absorção de água capilar, a massa específica e a porosidade. Os ensaios de resistência à compressão foram realizados em 48 e 72 horas, e a absorção de água, em corpos de prova preparados e acompanhados pelo período de 96 horas. A microestrutura dos CCA produzidos foi caracterizada por microscopia eletrônica de varredura (MEV). Verificou-se que existem expressivas alterações nas propriedades do CCA produzidos com ARC em substituição do AN, com a tendência de aumentar a densidade de massa aparente, bem com a resistência à compressão, a medida que aumenta-se o teor de ARC. Na análise dos resultados, percebeu-se que o uso de ARC alterou as propriedades dos concretos produzidos neste estudo exploratório, sem, entretanto, inviabilizar o seu emprego. Com um ajuste da dosagem, pode ser obtido um CCA produzido com ARC, cujo comportamento seja compatível com o comportamento de CCA produzido somente com o AN. / In the last years, the Brazilian construction industry is among those of national production sectors that have been having a great growing, mostly due to the incentive from the government and due to financed resources by private and public agents. This industry is also one of the major consumers of natural resources and energy, besides being the main generator of solid waste. One of these natural resources used in the constructions is sand. An environmentally friendly and economical alternative to reduce the extraction of natural resources is the use of recycled waste. The associated use of low volume of raw materials with alternative materials, like waste, is one of the ways to get more sustainability in the construction sector. Construction and building components made with autoclaved cellular concrete (ACC) employ four times less material than others with the same function. Other advantage of ACC is the performance of its properties like compressive strength, thermal and acoustic behavior, lower density, fire resistance. The aim of this research was to investigate the use of fine grains from recycled concrete aggregate (ARC) as partial sand replacement in the production of autoclaved aerated concrete. With the goal to find the mix proportion some pilot studies were made. After this, it was chosen a relation of 67% of cement and 33% of natural fine aggregate (sand). The lime was used in the amount of 0.45% of total cement and sand, and 0.3% of aluminium. The water to total solids ratio was 0.32. It was employed Portland cement type V according to Brazilian standards, calcitic lime, natural sand and ARC passing in sieve with 150 micron opening. The replacement rate of sand by ARC was 0%, 25% and 50%. From 24 hours after the mixing of materials, the samples were submitted to steam curing in an autoclave chamber for 6 hours. It was evaluated the compressive strength, the density, the capillary water absorption and porosity. The compression strength tests were performed at 48 and 72 hours. Water absorption tests were conducted for 96 hours after samples preparing. The capillary porosity was calculated with the capillary water absorption data. ACC's microstructure analysis was done by scanning electron microscopy (SEM). The results showed in general that the behavior of ACC produced with ARC differs significantly from the ACC produced with natural aggregate. When the ARC rate increases the apparent specific gravity also increases as well as the compressive strength. The observed increase in the apparent specific gravity is not desired. However this behavior of ACC done with RCA does not prevent the use of this recycled aggregate. An optimized study of pre-wetting of RCA could improve its performance as aggregate for use in ACC, once its grain size showed to be appropriated for this kind of use.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-06-30T19:06:20Z No. of bitstreams: 1 Bruno Rommel Cattani Sartori.pdf: 2512461 bytes, checksum: abb3f86120ab4514cee67cbf57c00264 (MD5) / Made available in DSpace on 2015-06-30T19:06:20Z (GMT). No. of bitstreams: 1 Bruno Rommel Cattani Sartori.pdf: 2512461 bytes, checksum: abb3f86120ab4514cee67cbf57c00264 (MD5) Previous issue date: 2013-08-16 / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul / Milton Valente / Este trabalho tem por finalidade contribuir para os estudos de durabilidade de concretos com a inserção de agregados graúdos reciclados de concreto (AGRC) e de cinza de casca de arroz (CCA) em concretos frente à carbonatação. Trabalhando com a hipótese de que o emprego de CCA possa mitigar o efeito da alta porosidade do AGRC nas propriedades do concreto, foram produzidos concretos com 0, 25 e 50% de AGRC; 0, 10 e 20% de CCA e relações água/aglomerante iguais a 0,42, 0,53 e 0,64. Para o ensaio de carbonatação acelerada, utilizou-se uma câmara de carbonatação com alimentação contínua de solução gasosa a 3% de CO2 e umidade relativa controlada, na qual os concretos permaneceram durante 63 dias. Os resultados apontaram para um efeito positivo do emprego de CCA nos concretos produzidos com AGRC. A substituição de cimento por CCA em média pode aumentar a resistência à compressão e à tração. Os concretos com relação a/agl 0,42, para a grande parte dos concretos ensaiados, retornaram resistências à compressão de 40 MPa à 55 MPa, com coeficiente de carbonatação de 1,0mm/dia½ a 1,5 mm/dia½, independente do teor de CCA. No entanto, concretos com relação a/agl mais alta (0,64), apresentaram resistência entre 15 MPa e 30 MPa, sendo que para grande parte destes o coeficiente de carbonatação se apresenta na faixa abaixo dos 3,0 mm/dia½ e acima do 2,0 mm/dia½. / This research contributes to the study of concrete carbonation using recycled concrete coarse aggregates (RCA) and rice husk ash (RHA). The use of RHA may contribute to reduce the effects of RCA's high porosity on the properties of the concrete. It was used 0,25 and 50% of RCA in replacement of natural aggregate; 0,10 and 20% of RHA as cement replacement; and water/binder 0.42, 0.53 and 0.64. For the accelerated carbonation test it was used a carbonation chamber with continuous feeding gaseous solution at 3% CO2 and controled relative humidity, where the concrete samples remained for 63 days. The results point to a positive effect of the use of RHA in concrete produced with RCA. Concretes with water/binder 0.42, for the most of the concrete tested, resulted in a compressive strength of 40 MPa to 55 MPa, with carbonation coefficient of 1.0mm/day1/2 to 1.5 mm/day1/2, independent of the amount of the RHA. However, concretes with higher water/binder (0.64) showed resistance between 15 MPa and 30 MPa, and for most of these the carbonation coefficient is below 3.0 mm/day1/2 and above 2.0 mm/day1/2.

Submitted by William Justo Figueiro (williamjf) on 2015-07-08T22:28:21Z No. of bitstreams: 1 11b.pdf: 3072047 bytes, checksum: 9c0305dfc155386ec7b41cddd7d15b40 (MD5) / Made available in DSpace on 2015-07-08T22:28:21Z (GMT). No. of bitstreams: 1 11b.pdf: 3072047 bytes, checksum: 9c0305dfc155386ec7b41cddd7d15b40 (MD5) Previous issue date: 18-05-18 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / FINEP - Financiadora de Estudos e Projetos / A construção civil é um dos setores que mais consome recursos naturais não renováveis, além de ser um dos principais geradores de resíduos sólidos urbanos (RSU). Dentre os diversos recursos naturais extraídos da natureza, os agregados utilizados na construção civil são os insumos minerais mais consumidos no mundo. Com a crescente restrição da extração de areias dos rios e a escassez de areias naturais é essencial que o setor da construção venha a adotar uma postura ambiental e sustentável, através de desenvolvimentos tecnológicos de processos de reciclagem de resíduos. Uma das alternativas para a construção civil, tanto do ponto de vista econômico quanto ambiental, no abastecimento de areia para a construção é a substituição das areias extraídas dos rios (areia natural) por resíduos de concreto, para a produção de argamassas. Este estudo tem como objetivo principal avaliar o comportamento de argamassas de revestimento com incorporação de agregado miúdo reciclado de concreto (AMRC), em substituição à areia natural extraída de rio (AN). Os AMRC foram obtidos a partir de resíduos de dois tipos de concreto empregados na pré-fabricação: de concreto submetido à cura térmica à vapor (ARCT) e outro de concreto submetido à cura convencional (ARCC). As argamassas foram confeccionadas com cimento CP II Z– 32 e cal CH-I, empregando-se traço em volume 1:1:6 com índice de consistência fixado em 260 ± 5 mm, para as três misturas de argamassas. O estudo foi desenvolvido em duas etapas. Na primeira etapa foram analisadas a caracterização morfológica e a distribuição granulométrica das areias. Na etapa seguinte analisou-se o comportamento e características das argamassas no estado fresco e no estado endurecido. A análise das argamassas no estado fresco contemplou dados de índice de consistência, penetração de cone, squeeze flow, retenção de água, densidade de massa e teor de ar incorporado. No estado endurecido as propriedades estudadas foram densidade de massa, resistência à compressão, resistência à tração na flexão, absorção de água por capilaridade e coeficiente de capilaridade, absorção de água, índices de vazios, massa específica, módulo de elasticidade dinâmico e porosidade por intrusão de mercúrio. Verificaram-se diferenças significativas no comportamento das argamassas confeccionadas com os dois agregados reciclados. No estado fresco foi observado perda de trabalhabilidade; perda de densidade de massa; aumento de ar incorporado, com perdas mais expressivas para a mistura com ARCC. No estado endurecido observou-se redução da resistência à compressão e da resistência à tração na flexão para as argamassas com ARCC. Os dados apontaram ainda diminuição de absorção de água por capilaridade; aumento da absorção de água por imersão; aumento do índice de vazios; aumento da massa específica e redução do módulo de elasticidade dinâmico para ambas as argamassas com agregados reciclados. / The construction industry is one of the sectors that consume non-renewable natural resources, besides being one of the main generators of municipal solid waste. Among the various natural resources extracted from nature, the aggregates used in construction are the most consumed mineral inputs in the world. With the increasing restriction of sand extraction from rivers and the scarcity of natural sands it is essential that the construction industry adopt an environmental and sustainable development, through technological processes to recycle waste. One of the alternatives to the construction industry, from an economical and environmental point of view, the supply of sand for construction is the replacement of sand extracted from rivers (natural sand) for concrete waste, for the production of mortars. This study aims at evaluate the behavior of rendering mortar with incorporation of recycled aggregate concrete, replacing the natural sand. The morphological characteristics and composition of two aggregates made from concrete were analysed: one from concrete subjected to thermal curing and other to conventional curing, compared with a river sand. Characterization tests were performed on fresh mortar (consistency index, cone penetration, squeeze flow, water retention, density and air content) and hardened mortar (density, compressive strength, flexural strength, capillarity water absorption and capillarity coefficient, water absorption, density, dynamic modulus of elasticity and mercury intrusion porosimetry). For this experiment were followed the requirements of NBR 13281 (ABNT, 2005) and used Brazilian CP II Z-32 cement and CH-I lime. A proportion of 1:1:6 (cement, lime and sand) by volume, with index consistency set at (260 ± 5) mm was adopted for the three mixtures of mortars. There were significant differences in the behavior of the two mortars made with recycled aggregates, such as: loss of workability; loss of density; increased air content (especially mixing with ARCC), in fresh stage. Reduction of compressive strength and reduced flexural strength (except in the mixture with ARCT), reduction of water absorption by capillarity, increased water absorption by immersion, an increase in the index of emptiness, increased density and reduced dynamic modulus of elasticity, in the hardened mortar.