Dissertations / Theses on the topic 'Mortier – Additifs'

Ce travail de recherche porte sur le retrait plastique et la fissuration induite pour les matériaux cimentaires présentant une grande surface libre par rapport au volume. Le mortier de référence considéré pour cette étude est une formulation par ailleurs exploitée dans le cadre des travaux initiés par le projet CEReM (Consortium pour l’Etude et la Recherche sur les Mortiers). Dans le cadre de cette thèse, un ensemble de moyens expérimentaux a été mis en place de façon à étudier le comportement du mortier au très jeune âge dans des conditions de retrait libre et de retrait empêché. La mesure sans contact du retrait surfacique est réalisée au moyen d’une instrumentation optique. Une nouvelle technique de retrait empêché a été également mise en place : elle se distingue des autres couramment rencontrées dans la littérature par sa simplicité et elle permet d’avoir directement l'évolution de la contrainte interne de traction dans le matériau au cours du retrait. L'ensemble de ces protocoles expérimentaux ont permis d’étudier l'influence des fibres (fibres de verre, fibres de polypropylène), de l'adjuvant anti-retrait (type Glycol), des poudres de polymère (éther de cellulose, le latex “EVA”) sur le comportement au très jeune âge du matériau cimentaire. Une partie de la thèse est consacrée à la modélisation numérique du comportement du matériau cimentaire au cours du retrait plastique (du gâchage jusqu'au seuil de durcissement). Dans cette partie, un modèle élastoplastique est proposé. La plasticité est décrite par le critère isotrope de Von Mises dans lequel nous avons introduit une évolution de la surface de charge en fonction de la maturation du matériau. L'implantation de ce modèle de comportement dans un code de calcul a conduit à la simulation numérique de l’essai de retrait empêché : une comparaison entre modèle et expérience est ensuite discutée

La gestion des déchets agricoles et la promotion de matériaux de construction durables offrent de nombreux avantages considérables. En intégrant des pratiques durables dans le secteur de la construction, nous avons la capacité de réduire notre empreinte écologique en limitant l'exploitation excessive des ressources naturelles.La recherche menée dans la présente étude vise à développer un béton et un mortier de ciment structurels allégés avec des agrégats organiques de grignons d’olive. Deux types d’agrégats ont été utilisés selon qu’ils soient mélangés ou non avec des margines. L'objectif principal de cette étude est l’évaluation expérimentale des propriétés mécaniques et thermiques des éprouvettes de béton et de mortier allégés par rapport aux éprouvettes de béton et de mortier ordinaires. Elles ont été préparées en utilisant des agrégats des grignons d’olive à l’état sec et saturé, avec un pourcentage de substitution de sable naturel variant de 0% à 15%. Les résultats ont montré que la formulation optimale pour la production d’un béton allégé consiste en 5% d’agrégats de grignons d’olive à l’état sec et mélangés avec les margines. Cette formulation, offre de meilleures propriétés mécanique, notamment une résistance à la compression de 25 MPa, une résistance à la traction de 4,61 MPa et un module d'élasticité dynamique de 44,39 GPa. En plus, le matériau réalisé présente une masse volumique sèche réduite entraînant une diminution d’environ 5,69% par rapport au béton de référence.Pour le mortier de ciment, les meilleurs résultats ont été obtenus avec un mélange contenant 5% d’agrégats de grignons d’olive à l’état sec et mélangés avec les margines. Les résultats ont montré un effet marginal sur la résistance à la compression (Rc), atteignant 33,50 MPa, et ce après 28 jours de durcissement. Cependant, pour le béton et le mortier, l'analyse microstructurale a révélé une faible adhérence entre les agrégats de grignons d’olive et la matrice cimentaire au niveau de la Zone de Transition Interfaciale. Les tests expérimentaux ont montré également que l'augmentation de la teneur en agrégats de grignons d'olive réduit la vitesse de propagation des ultrasons et le module d'élasticité dynamique du béton et du mortier allégé ainsi que leur maniabilité tout en augmentant leur porosité.En ce qui concerne les propriétés thermiques des matériaux élaborés, l'incorporation d'agrégats de grignons d'olive a entraîné une amélioration de la résistance thermique. Dans le cas du béton allégé avec 5% d’agrégats de grignons d’olive à l’état sec et mélangés avec les margines, la conductivité thermique (λ) est passée de 1,3 W/m.K (pour l’éprouvette témoin) à 0,86 W/m.K. Dans le cas du mortier de ciment contenant 5% d’agrégats de grignons d’olive à l’état sec et mélangés avec les margines, la conductivité thermique (λ) est passée de 1,1 W/m.K (éprouvette témoin) à 0,87 W/m.K.En conclusion, cette étude a révélé que les matériaux élaborés et testés dans les conditions de laboratoires répondent aux normes requises pour une utilisation générale dans le bâtiment
The management of agricultural waste and the promotion of sustainable building materials offer many considerable benefits. By integrating sustainable practices into the construction sector, we have the ability to reduce our ecological footprint by limiting the excessive exploitation of natural resources. The research conducted in this study aims to develop a lightweight structural concrete and cement mortar using organic olive pomace aggregates. Two types of aggregates were used, depending on whether they were mixed with or without olive mill wastewater. The main objective of this study is to experimentally evaluate the mechanical and thermal properties of lightened concrete and mortar specimens in comparison with ordinary concrete and mortar specimens. They were prepared using dry and saturated olive pomace aggregates, with a percentage substitution of natural sand ranging from 0% to 15%. The results showed that the optimal formulation for producing lightweight concrete consists of 5% dry olive pomace aggregates mixed with olive mill wastewater. This formulation offers better mechanical properties, including a compressive strength of 25 MPa, a tensile strength of 4.61 MPa, and a dynamic modulus of elasticity of 44.39 GPa. Additionally, the resulting material has a reduced dry bulk density, leading to a decrease of approximately 5.69% compared to the reference concrete. For cement mortar, the best results were obtained with a mixture containing 5% dry olive pomace aggregates mixed with olive mill wastewater. The results showed a marginal effect on compressive strength (Rc), reaching 33.50 MPa after 28 days of curing. However, for both concrete and mortar, microstructural analysis revealed weak adhesion between olive pomace aggregates and the cement matrix at the Interfacial Transition Zone. Experimental tests also showed that increasing the content of olive pomace aggregates reduces the ultrasound propagation velocity and the dynamic modulus of elasticity of lightweight concrete and mortar, as well as their workability, while increasing their porosity.As regards the thermal properties of the developed materials, the incorporation of olive pomace aggregates led to an improvement in thermal resistance. In the case of lightweight concrete with 5% of dry olive pomace aggregates mixed with olive mill wastewater, the thermal conductivity (λ) decreased from 1.3 W/m·K (for the control specimen) to 0.86 W/m·K. In the case of cement mortar containing 5% of dry olive pomace aggregates mixed with olive mill wastewater, the thermal conductivity (λ) decreased from 1.1 W/m·K (control specimen) to 0.87 W/m·K. In conclusion, this study revealed that the materials developed and tested under laboratory conditions meet the required standards for general use in construction

La fabrication additive ou impression 3D est la technique la plus récente introduite dans le secteur de la construction. De nombreuses questions restent posées, notamment la maîtrise des propriétés à l'état frais et durci du matériau utilisé, et la stratégie de renforcement pour fournir la ductilité et les capacités structurelles des éléments.Cette thèse traite de l’effet des propriétés à l’état frais du matériau sur l’état durci et sur la réponse mécanique des éléments imprimés. Le travail a commencé par la formulation et la caractérisation rhéologique de nouveaux mélanges imprimables. La thixotropie des mortiers, c’est à dire de la variation du seuil de cisaillement au cours du temps, a été particulièrement étudiée et permet une meilleure compréhension de l'effet de certains adjuvants chimiques et minéraux sur la vitesse de structuration du mélange. Ensuite, la relation entre la rhéologie du matériau et la liaison développée avec les armatures a été explorée, en tenant compte de la direction des couches par rapport à la barre sur la qualité de la liaison. Enfin, cette recherche comprend une caractérisation microstructurale des matériaux imprimés, ainsi qu'une évaluation de la durabilité des éléments imprimés lorsqu'ils sont soumis à des attaques d'acide sulfurique.Plus précisément, l'évolution du seuil de cisaillement a été mesurée pour différents mélanges imprimables sur une certaine période de temps à l'aide du pénétromètre à chute libre, et l'effet de certains additifs chimiques et minéraux a été examiné. Ici, il a été constaté que les paramètres de formulation influencent le taux de structuration du mélange, mais dans des amplitudes différentes. En particulier, l'ajout de superplastifiant, de filler calcaire et l’augmentation du dosage en eau diminuent le taux de structuration du matériau, alors que l’agent de viscosité l'augmente. Ensuite, l'effet de la rhéologie du matériau, de la méthode d'impression et de la direction des couches par rapport à la barre, sur la qualité de la liaison acier/béton imprimé a été étudié à travers des tests d'arrachement sur des éléments imprimés réalisés manuellement ou à l'aide d'une imprimante automatisée. Ici, différents mélanges avec des ouvrabilités et des comportements thixotropes différents ont été utilisés. Des couches parallèles et perpendiculaires à la barre ont été imprimées. Les résultats ont montré que les échantillons imprimés étaient capables de développer une contrainte d’adhérence acceptable par rapport aux échantillons moulés. Ces résultats indiquent également que l'impression manuelle peut être considérée comme une méthode d'essai préliminaire pour simuler le travail d'une imprimante, et que la rhéologie du matériau n’a pas eu d’effet majeur sur la liaison avec les barres. De plus des couches imprimées parallèlement à la barre présentent une meilleure liaison par rapport à celle obtenue pour les échantillons ayant des couches imprimées perpendiculairement. Concernant l'évaluation de la microstructure et de la durabilité des échantillons imprimés, différents mélanges ont été utilisés pour couvrir une large gamme de propriétés des matériaux. Ici, des échantillons imprimés ont été exposés à différentes concentrations d'acide sulfurique et la microstructure des échantillons dégradés et non dégradés a été évaluée. Les résultats ont montré que les échantillons qu'ils soient imprimés ou non, ont les mêmes performances contre une attaque acide. En particulier, les échantillons imprimés n'ont montré aucun signe de faiblesse entre les couches, ni à une échelle micro ni à une échelle macro. La différence majeure entre un échantillon imprimé et un échantillon coulé est que les échantillons imprimés ont une distribution et une morphologie de la taille des pores plus étalées, ce qui est causé par les paramètres d'impression utilisés
Currently, the latest technique being introduced to the construction field is known as Additive Manufacturing or 3D printing. Many challenges encounter this technique, notably the fresh and hardened state properties of the cementitious material used for 3D printing; and the reinforcement strategy to provide ductility and tensile capacity for structural elements.This thesis deals with the effect of the material’s fresh state properties on the hardened state and mechanical response of 3D printed elements. Initially, the work has started by formulating new printable mixes and testing their rheological properties; in particular their thixotropic behavior, depending on the material’s yield stress variation over a certain period of time. After then, the results were linked to the mechanical and hardened state performance of 3D printed elements. Thus, a better understanding of the effect of certain chemical and mineral admixtures on the thixotropic behavior of the mix was carried out. Then, the relation between the material’s rheology and thixotropic behavior with the bond developed between printed layers and reinforcing bars has been exposed, and the effect of the layers direction with respect to the steel bar on the quality of the bond was further assessed. At last, this research includes a microstructural characterization of 3D printed materials, as well as a durability assessment of the printed elements performance when subjected to sulfuric acid attacks.More precisely, the yield stress evolution so-called thixitropic behavior was measured for different printable mixes over a certain period of time using the fall-cone penetrometer; and the effect of some chemical and mineral additives was considered. Herein, it was found that the material variables influence the structuration rate of the mix, but in different magnitudes. In particular, the addition of HRWR, Limestone filler and water content decrease the structuration rate of the material, whereas VMA increases it. Afterwards, the effect of the material’s rheology, printing method and layers direction with respect to steel bar, on the developed link have been studied through a series of pull-out tests done over printed elements made either manually using a laboratory device or using an automated printer. Herein, different mixes with different workabilities and thixotropic behaviors were used. Alongside, concrete layers were printed either parallel or perpendicular to the steel bar. The overall results showed that printed samples were able to develop an acceptable bond strength in comparison with the mold casted specimens. Implicitly, these results indicated first that the manual printing can be considered as a preliminary testing method to simulate the work of an actual printer; second, the material’s rheology did not majorly affect the bond with steel bars; third, parallel printed layers to the steel bar can still provide better bonding with it in comparison to that attained by the samples having perpendicular printed layers. As for the microstructural and durability assessment of 3D printed samples, different mixes were used to cover a wider range of material properties. Here, 3D printed samples were exposed to different concentrations of sulfuric acid, and the microstructure of the degraded and non-degraded samples was assessed. The results showed that concrete samples whether printed or not have the same performance when subjected to acid attack. In particular, printed samples did not show any sign of inter-layer weaknesses, neither at a micro nor macro scales. However, the only difference between a printed specimen and a non-printed one is that printed samples have a more spread pore size distribution and morphology, which is caused by printing parameters used

Les objectifs de cette thèse sont de mieux comprendre le phénomène d’autocicatrisation naturelle et d’initier une démarche en vue de proposer des approches technologiques pratiques, fiables et peu couteuses qui permettront d’optimiser et de favoriser le potentiel d’autocicatrisation des bétons et des matériaux cimentaires en général. Les approches proposées consistent à introduire, dans les formulations des matériaux cimentaires, des réactifs internes latents qui permettront d’augmenter le potentiel d’autocicatrisation par différents mécanismes. Trois types de réactifs sont étudiés; des ajouts cimentaires riches en chaux libre, des ajouts granulés riches en ciment anhydre et/ou en chaux libre et des micro-granulats de verre riches en silice amorphe. L’ajout des ajouts cimentaire et des granulés visent à augmenter le potentiel d’autocicatrisation par carbonatation. L’ajout des micro-granulats de verre a pour objectif de créer, dans les fissures un gel silico-calcaire alcalin expansif. Il en ressort que l’augmentation de la teneur en portlandite de la matrice en ajoutant de réactifs riches en chaux libre augmente considérablement le potentiel d’autocicatrisation de fissures larges (>200 µm). L’ajout de granulés faiblement hydratés à base de ciment ou de ciment avec agent expansif à base de chaux libre confère aux mortiers une capacité de cicatrisation accrue. La formation de gel expansif dans les fissures suite à l’activation de la réaction alcali-silice des micro-granulats de verre ne confère pas à la matrice cimentaire un fort potentiel d’autocicatrisation entre 0 et 12 mois.

Les adjuvants polymère peuvent apporter de signifcatives améliorations à diverses propriétés de mortiers et de bétons. Cependant, même si de nombreux produits commerciaux sont actuellement sur le marché, il est impossible à ce jour d'établir un lien formel entre les caractéristiques physico-chimiques de l'adjuvant et son impact sur différentes propriétés du matériau auquel il est ajouté. L'objectif de cette étude est donc la synthèse d'adjuvants modèles afin d'étudier les impacts respectifs de deux aspects des latex : les propriétés liées à la nature chimique du polymère (hydrophilie et Tg), ainsi que celles liées à la nature de la surface des particules (tensioactifs et colloïdes protecteurs de différentes natures, charges greffées). Il sera alors possible d'associer chaque modification des proprités du mortier à la caractéristique du latex qui en est à l'origine. Nous étudierons ensuite la stabilité de l'adjuvant, son adsorption éventuelle sur les phases minérales ainsi que sa localisation dans la microstructure du mortier. Enfin, nous montrerons que la présence d'un adjuvant polymère modifie le processus d'hydratation du ciment et influence directement le nombre ainsi que la taille des hydrates formés

Ce travail propose de quantifier par une méthodologie expérimentale rigoureuse l'effet des additions minérales sur la variation du besoin en eau et du besoin en adjuvant des mortiers, leur contribution au remplissage de la porosité et à l'amélioration des résistances mécaniques ainsi que leur action aux propriétés de transfert et à la résistance chimique en milieu agressif sévère. Les principales variables de formulation sont la nature minéralogique, la finesse et la quantité de l'addition, le type de ciment et son dosage. Les résultats obtenus montrent que les additions, indépendamment de leur nature et jusqu'à une certaine quantité, contribuent à maintenir les propriétés de transfert des mortiers sans former un volume important de nouveaux produits hydratés capables de réduire la porosité ouverte. En revanche, la nature et la finesse des additions sont déterminantes pour leur contribution au développement des résistances mécaniques et dans un moindre degré à la résistance chimique
This work proposes to quantify by a rigorous experimental methodology the effect of mineral additions on the water requirement and the superplasticizer requirement variation of mortars, their contribution to filling the porosity and to improving the mechanical strength, and their action to the transfer properties and to the chemical resistance in hard aggressive medium. The principal mixture proportion variables are the mineralogical nature, fineness and quantity of the addition, the cement type and proportioning. The obtained results show that the additions, independently of their nature and until a certain quantity, contribute to maintain the mortars transfer properties without forming a high volume of new hydrated products able to reduce open porosity. On the other hand, the additions nature and fineness are determining for their contribution to the mechanical strength development and in a lesser extent to the chemical resistance

Dans le but de gérer les déchets coquilliers générés par la pêche et l’aquaculture, une valorisation dans les matériaux cimentaires est envisagée. Trois types de coquilles présentes localement sont utilisés : huître, coquille Saint-Jacques et crépidule. Chacun d’eux est trié, nettoyé, concassé, tamisé pour obtenir les fractions granulométriques : 0/0,063 mm, 0,063/2 mm, 2/4 mm, 4/6,3 mm, 6,3/10 mm et 10/14 mm. Les caractéristiques des coquilles sont déterminées pour définir leurs potentiels et appréhender leur comportement dans les matériaux cimentaires. Les conclusions confortent ce choix de valorisation et l’intégration des coquilles est étudiée dans les mortiers et les bétons, en tant qu’additions, granulats et fillers. Les résultats sur mortiers montrent que l’huître et la coquille Saint-Jacques sont performantes sous forme d’additions ; les crépidules sont plus appropriées en tant que granulats. Globalement, l’ajout de coquilles en remplacement de granulats entraîne une perte d’ouvrabilité et de résistance du matériau cimentaire. La comparaison des mortiers et bétons est faite à consistance similaire : un ajout d’eau est donc nécessaire pour conserver l’ouvrabilité et peut expliquer les baisses de résistances. Un superplastifiant est alors ajouté à certaines formulations de béton. Leurs résistances sont 1,1 à 1,9 fois plus importantes que celles des bétons témoins. Les analyses microstructurales ne révèlent pas la présence d’un nouveau matériau formé : les coquilles auraient donc un rôle de remplissage dans la matrice cimentaire. Ce travail de recherche témoigne de la possible et bénéfique intégration des coquilles dans les matériaux cimentaires
This research work was born from a desire to manage waste shells produced by fishing and shellfish farming activities. In this purpose, a study of waste shells reusing in cementitious materials is envisaged. Three types of local shells are used: oyster, scallop and slipper limpet. Each of them is sorted, cleaned, crushed, sieved to obtain the grading fractions: 0/0,063 mm, 0,063/2 mm, 2/4 mm, 4/6,3 mm, 6,3/10 mm and 10/14 mm. Shells properties are determined to define their best potentialities and to comprehend their behavior in cementitious materials. The conclusions consolidate this reuse idea, and shells integration is studied in mortar and concrete, as additions, aggregates and fillers. The mortars results show that oyster and scallop shells are successful as additions, slipper limpet shells are better as aggregates. From a global point of view, the aggregates substitution by shells decreases workability and resistance of cementitious materials. Mortar and concrete were made with the same workability; an addition of water is thus necessary to maintain the workability and can explain the resistance decrease. A superplasticizer is then added to some concrete. Their resistances are 1. 1 to 1. 9 times more important than control concrete specimens. The microstructural analysis survey reveals that no new material seems to be formed; shells would thus have a role of filling in cement matrix. This research work confirms the possible and beneficial integration of shells as addition, fillers or aggregates into cementitious materials

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
A vitamina E é usada nas dietas com a finalidade de melhorar o crescimento, a resistência ao estresse e a doenças, assim como a sobrevivência de peixes. Também pode ser eficiente na conservação do pescado durante o processamento e estocagem, inibindo a degradação dos lipídios pela oxidação. O presente trabalho avaliou os efeitos antioxidantes da vitamina E in vivo e in vitro na qualidade final dos hambúrgueres produzidos com filés de tilápias congelados durante 0, 30, 60 e 90 dias. Foi utilizado um delineamento inteiramente casualizado, com seis tratamentos, em esquema fatorial 3x2, caracterizado pela suplementação de dois níveis de vitamina E nas dietas (100 e 200 mg / kg de ração) e o grupo controle (zero mg/kg de ração) e adição ou não de 100 ppm de vitamina E aos hambúrgueres, com quatro repetições. Os peixes, com peso médio inicial de 184,23 + 1,68g foram alimentados com as dietas experimentais durante 63 dias. Após esse período, foram abatidos e os filés processados em hambúrgueres. Foram avaliados os parâmetros de desempenho, composição centesimal e a oxidação lipídica, determinada pelas substâncias reativas ao ácido tiobarbitúrico (SRATB). Os resultados mostraram que não houve diferença significativa para as variáveis de ganho de peso, conversão alimentar e crescimento específico entre os tratamentos. A composição química variou dentro dos valores encontrados para pescados. O aumento do nível de vitamina E promoveu redução nos valores de SRATB das amostras em todos os intervalos de tempo, e que a adição in vivo da vitamina E protegeu os hambúrgueres da oxidação lipídica de forma mais eficiente do que a adição in vitro, sendo que a interação entre ambas resultou em maior redução nas taxas de oxidação.
Vitamin E is used in diets with the aim of enhancing growth, resistance to stress and pathology, and also fish survival. It can be efficient in fish conservation during processing and frozen storage, inhibiting lipid degradation from oxidation. The present work evaluated the antioxidant effects of vitamin E utilization in vivo and in vitro in the final quality of hamburgers made from tilapia filets during frozen storage over 3 months. A randomized design, in a 3x2 factorial scheme was utilized, which correspond to the two levels of diet vitamin E (100 and 200 mg / kg diet) and the control group (zero mg/kg diet) and addition or not of 100 ppm of vitamin E to the hamburgers, with four repetitions. The fishes, with initial weight 184.23 + 1.68 g, were fed the experimental diets for 63 days, after which they were killed and processed into hamburgers. The performance parameters analyzed were centesimal composition and lipid oxidation, determined by the thiobarbituric acid reactive substances (TBARS). The results showed no significant difference between treatments for weight gain, food conversion or specific growth. The chemical composition varied within the values found for fish. Increased vitamin E levels promoted reduction of TBARS values over all time intervals. This means values suggested that the addition in vivo of tocopherol protected the hamburgers from lipid oxidation more efficiently when compared to in vitro addition, but the interaction between both resulted in higher reduction in rate of oxidation.

Etudes de l'influence sur le comportement mecanique des mortiers de six ajouts ultra-fins (trois fumees de silice condensee et trois alumines de synthese), en constatant l'absence d'influence d'une eventuelle reaction pouzzolanique et par contre l'influence du remplissage des porosites

[EN] The present research suggests, on one hand, optimizing a multi-technical method for the characterization of organic compounds and traditional lime mortars to use in monumental buildings of antiquity. To illustrate the effectiveness of this methodology it has been applied to a study case, the stucco from mural painting of Maya culture (Ancient Mesoamerica), which has been chosen by the need to continue studying the composition of preparation layers of these stuccos. There are two reasons for this choice: the first one is that knowledge of materials and of execution techniques of these surfaces is providing new data to understand the technological complexity of this culture; and the second one is based on the fact that just this type of research will allow us to know with certainty how these preparation layers were made and, this way, ensure the correct interventions of conservation and restoration. From these considerations, the study conducted establishes a methodological approach that comes from the specialized literature search of geographical and cultural context, the physical (geology and climatology) and biological environment (flora and vegetation) from Yucatan Peninsula (Mexico), getting theoretical knowledge necessary to deal with a detailed description and characterization of the raw materials from the geological environment that were used in the manufacture of the preparation layers from Maya mural painting. The method continues with the use of instrumental analysis techniques such as optical microscopy (OM), polarizing optical microscopy (POM), infrared Fourier transform spectroscopy (FT-IR), x-ray diffraction (XRD), scanning electron microscopy-x-ray microanalysis (SEM-EDX), x-ray microdiffraction (µ-XRD), transmission electron microscopy (TEM) and the optimization of instrumental techniques for analyzing organic compounds, such as gas chromatography/mass spectrometry (GC/MS). On the other hand, the current researches tend to reinforce the idea of incorporating organic components to the cementitious matrix of historical mortars. There is a debate about whether these additives modify the fresh mortar properties and if they also improve the hardened mortar properties. In this study is suggested the development of a method of making lime mortars with an application in the field of restoration, to provide adequate quality control over their constituents. To do this, it has been used an experimental research of air lime mortar paste to which cementitious matrix, two natural organic additives of vegetable origin in different proportions have been incorporated, so changes in its behavior related to the main rheological, hydraulics and physical-mechanical properties of the mortar can be assessed, as ecological and sustainable alternative to non-biodegradable and irreversible synthetic resins, and to ensure greater compatibility with the original materials.
[ES] La presente investigación propone, de un lado, la optimización de un método multitécnica para la caracterización de componentes orgánicos y morteros de cal tradicionales en construcciones monumentales de la antigüedad. Para ejemplificar la eficacia de esta metodología, se ha aplicado a un caso de estudio, los estucos de la pintura mural de la cultura maya (Antigua Mesoamérica), que ha sido elegido por la necesidad de seguir estudiando la composición de las capas de preparación de estos estucos. Existen dos motivos para esta elección: el primero es que el conocimiento de los materiales y de las técnicas de ejecución de estas superficies está aportando nuevos datos para comprender la complejidad tecnológica de esta cultura; y el segundo se basa en que tan sólo este tipo de investigaciones nos permitirán conocer con certeza como se realizaron estas capas de preparación y, de este modo, garantizar las correctas intervenciones de conservación-restauración. A partir de estas consideraciones, el estudio llevado a cabo establece un planteamiento metodológico que parte de la búsqueda de bibliografía especializada del contexto geográfico, del marco cultural, del medio físico (la geología y la climatología) y biológico (la flora y la vegetación) de la Península de Yucatán (México), consiguiendo el conocimiento teórico necesario para afrontar una descripción y caracterización ajustada de las materias primas del entorno geológico que se usaron en la manufactura de las capas de preparación de la pintura mural maya. El método continua con el aprovechamiento de técnicas instrumentales de análisis, como la microscopia óptica (MO), la microscopia óptica de luz polarizada (MOP), la espectroscopia infrarroja por transformada de Fourier (FT-IR), la difracción de rayos-x (DRX), la microscopia electrónica de barrido-microanálisis de rayos-x (SEM-EDX), la microdifracción de rayos-x (µ-DRX), la microscopía electrónica de transmisión (TEM) y la optimización de técnicas instrumentales avanzadas para el análisis de compuestos orgánicos, como la cromatografía de gases/espectrometría de masas (GC/MS). Por otro lado, las investigaciones actuales tienden a reforzar la idea de incorporar componentes orgánicos a la matriz cementante de los morteros históricos. Existe un debate sobre si estos aditivos modifican las propiedades del mortero fresco y si, además, mejoran las propiedades del mortero endurecido. En este estudio se propone la puesta a punto de un método de elaboración de morteros de cal normalizados de aplicación en el campo de la restauración, que permita un adecuado control de calidad sobre sus constituyentes. Para ello, se ha partido de la investigación experimental de morteros de cal aérea en pasta a los que se les ha incorporado en su matriz cementante dos aditivos orgánicos naturales de origen vegetal en proporciones variables, de modo que se puedan valorar las modificaciones de su comportamiento en relación a las principales propiedades reológicas, hídricas y físico-mecánicas del mortero, como alternativa ecológica y sostenible de las resinas sintéticas no biodegradables e irreversibles, y para asegurar una mayor compatibilidad con los materiales originales.
[CAT] La present investigació proposa, per una banda, l'optimització d'un mètode multitècnica per a la caracterització de components orgànics i morters de calç tradicionals en construccions monumentals de l'antiguitat. Com exemplicació de l'eficàcia, aquesta metodologia s'ha aplicat a un cas d'estudi, els estucs de la pintura mural de la cultura maia (Antiga Mesoamèrica). L'elecció d'aquest cas d'estudi està motivada per la necessitat de seguir estudiant la composició de las capes de preparació d'aquests estucs. Existeixen dos motius per a això: el primer és que el coneixement dels materials i de les tècniques d'execució d'aquestes superfícies està aportant noves dades per a comprendre la complexitat tecnològica d'aquesta cultura i el segon és que, sols aquesta classe d'investigacions ens permetran conèixer amb certesa com foren realitzades aquestes capes de preparació, i en conseqüència, garantir correctes intervencions de conservació-restauració. A partir d'aquestes consideracions, l'estudi portat a terme estableix un plantejament metodològic que parteix de la recerca de bibliografia especialitzada, aconseguint un coneixement teòric, del context geogràfic, del marc cultural, del medi físic (la geologia i la climatologia) i biològic (la flora i la vegetació) de la Península de Yucatán (Mèxic), necessari per a afrontar la correcta descripció i caracterització de les matèries primeres de l'entorn geològic, utilitzades en la manufactura de las capes de preparació de la pintura mural maia i conseqüentment, per a la correcta interpretació dels estucs procedents dels assentaments arqueològics de les Terres Baixes Maies del Nord (Península de Yucatán, Mèxic) estudiats, mitjançant l'aprofitament de tècniques instrumentals d'anàlisis, com la microscòpia òptica (MO), la microscòpia òptica de llum polaritzada (MOP), l'espectroscòpia infraroja per transformada de Fourier (FT-IR), la difracció de raigs-x (DRX) i la microscòpia electrònica de rastreig-microanàlisis de raigs-x (SEM-EDX), la microdifracció de raigs-x (µ-DRX), la microscòpia electrònica de transmissió (TEM) i l'optimització de tècniques instrumentals avançades, per l'anàlisi de compostos orgànics, com la cromatografia de gasos/espectrometria de masses (GC/MS). Per altra banda, les investigacions actuals tendeixen a reforçar la idea d'incorporar components orgànics als morters històrics a la matriu cimentant. Existeix un debat sobre si aquests additius modifiquen les propietats del morter en estat fresc i si, a més a més, milloren les propietats del morter en estat endurit. En aquest estudi, es proposa la posada a punt d'un mètode d'elaboració de morters de calç normalitzats d'aplicació en el camp de la restauració, que permeti un adequat control de qualitat sobre els seus constituents, a partir de la investigació experimental de morters de calç aèria en pasta amb la incorporació de dos additius orgànics naturals d'origen vegetal, a la seva matriu cimentant, en proporcions variables, per tal de valorar les modificacions del seu comportament en relació a les principals propietats reològiques, hídriques i fisicomecàniques del morter, com alternativa ecològica i sostenible de les resines sintètiques no biodegradables i irreversibles, i per a assegurar una major compatibillitat amb els materials originals.
Guasch Ferré, N. (2016). OPTIMITZACIÓ DE MÈTODES MULTITÉCNICA PER A LA CARACTERITZACIÓ DE COMPONENTS ORGÀNICS I MORTERS DE CALÇ TRADICIONALS DE L'ANTIGUITAT. DESENVOLUPAMENT DE METODOLOGIES EXPERIMENTALS PER A LA SEVA CONSERVACIÓ I RESTAURACIÓ. APLICACIÓ A UN CAS D'ESTUDI: ELS ESTUCS DE LA PINTURA MURAL DE LA CULTURA MAIA (ANTIGA MESOAMÈRICA) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61385
TESIS

Orientador: Léa Silvia Sant'Ana
Banca: Rose Meire Vidotti
Banca: Luiz Edivaldo Pezzato
Resumo: A vitamina E é usada nas dietas com a finalidade de melhorar o crescimento, a resistência ao estresse e a doenças, assim como a sobrevivência de peixes. Também pode ser eficiente na conservação do pescado durante o processamento e estocagem, inibindo a degradação dos lipídios pela oxidação. O presente trabalho avaliou os efeitos antioxidantes da vitamina E "in vivo" e "in vitro" na qualidade final dos hambúrgueres produzidos com filés de tilápias congelados durante 0, 30, 60 e 90 dias. Foi utilizado um delineamento inteiramente casualizado, com seis tratamentos, em esquema fatorial 3x2, caracterizado pela suplementação de dois níveis de vitamina E nas dietas (100 e 200 mg / kg de ração) e o grupo controle (zero mg/kg de ração) e adição ou não de 100 ppm de vitamina E aos hambúrgueres, com quatro repetições. Os peixes, com peso médio inicial de 184,23 + 1,68g foram alimentados com as dietas experimentais durante 63 dias. Após esse período, foram abatidos e os filés processados em hambúrgueres. Foram avaliados os parâmetros de desempenho, composição centesimal e a oxidação lipídica, determinada pelas substâncias reativas ao ácido tiobarbitúrico (SRATB). Os resultados mostraram que não houve diferença significativa para as variáveis de ganho de peso, conversão alimentar e crescimento específico entre os tratamentos. A composição química variou dentro dos valores encontrados para pescados. O aumento do nível de vitamina E promoveu redução nos valores de SRATB das amostras em todos os intervalos de tempo, e que a adição "in vivo" da vitamina E protegeu os hambúrgueres da oxidação lipídica de forma mais eficiente do que a adição "in vitro", sendo que a interação entre ambas resultou em maior redução nas taxas de oxidação.
Abstract: Vitamin E is used in diets with the aim of enhancing growth, resistance to stress and pathology, and also fish survival. It can be efficient in fish conservation during processing and frozen storage, inhibiting lipid degradation from oxidation. The present work evaluated the antioxidant effects of vitamin E utilization in vivo and in vitro in the final quality of hamburgers made from tilapia filets during frozen storage over 3 months. A randomized design, in a 3x2 factorial scheme was utilized, which correspond to the two levels of diet vitamin E (100 and 200 mg / kg diet) and the control group (zero mg/kg diet) and addition or not of 100 ppm of vitamin E to the hamburgers, with four repetitions. The fishes, with initial weight 184.23 + 1.68 g, were fed the experimental diets for 63 days, after which they were killed and processed into hamburgers. The performance parameters analyzed were centesimal composition and lipid oxidation, determined by the thiobarbituric acid reactive substances (TBARS). The results showed no significant difference between treatments for weight gain, food conversion or specific growth. The chemical composition varied within the values found for fish. Increased vitamin E levels promoted reduction of TBARS values over all time intervals. This means values suggested that the addition in vivo of tocopherol protected the hamburgers from lipid oxidation more efficiently when compared to in vitro addition, but the interaction between both resulted in higher reduction in rate of oxidation.
Mestre

La vitesse à laquelle le monde actuel fonctionne a des répercutions directes sur tout ce qui nous entoure et, en premier plan, sur le marché de la construction dont les cirières sont de plus en plus exigeants tels que les courts délais de construction, la complexité des formes, etc. L’utilisation des bétons fluides dont les propriétés rhéologiques sont bien maîtrisées est une clé pour satisfaire à ces critères, d’autant plus qu’on se trouve au seuil d’une nouvelle ère dans le monde de la construction incluant l’impression 3D des bétons. Cependant, une sélection adéquate des ajouts minéraux (AM) et des adjuvants chimiques (superplastifiants, SP et agents de viscosité, AV) qui entrent dans la conception des bétons fluides s’avère un problème crucial. Un programme expérimental très étendu est mené pour mettre la lumière sur l’effet de huit différents AM dans des systèmes binaires et ternaires ainsi que l’effet de leurs interactions avec les adjuvants chimiques (SP et AV) sur les propriétés des mortiers de bétons équivalents (MBE). Deux classes de bétons fluides sont visées dans cette étude comprenant les bétons autoplaçants (BAP) pour la construction des bâtiments et les bétons semi-fluides (BSF) pour les infrastructures de transport. Une attention particulière est portée sur les propriétés rhéologiques, sans pour autant négliger la chaleur d’hydratation ainsi que les propriétés mécaniques. Les résultats ont montré qu’il est difficile de faire une généralisation sur l’influence des AM sur les propriétés des MBE. Les propriétés physiques des AM telles que la finesse, la forme ou encore la granulométrie des particules sont des facteurs qui jouent un rôle important dans la rhéologie des bétons fluides. Cependant, l’influence de ces facteurs peut être masquée par l’interaction physique et chimique qui peut avoir lieu entre les poudres et les adjuvants chimiques utilisés (type de SP en présence de ou sans AV compatibles). La morphologie des particules des AM a un effet direct sur la viscosité plastique des MBE. Une forme angulaire et irrégulière (facteur de Ferret autour de 0,4), contribue à augmenter la viscosité plastique des MBE et une forme sphérique (facteur de Ferret proche de 1) contribue à diminuer leur viscosité plastique. Par ailleurs, les résultats de l’analyse statistique ont montré que l’influence des AM en combinaison ternaire (une poudre à faible réactivité avec une poudre à réactivité élevée), en présence d’un rapport eau/poudres (E/P) relativement élevé (0,45), sur la majorité des réponses n’est que la somme des effets individuels de ces poudres. Par contre, un effet d’interaction entre les poudres pour certaines réponses a commencé légèrement à prendre place lorsque le rapport E/P est diminué à 0,41. Cependant, dans le développement des résistances à la compression à 28 et 91 jours, les poudres à réactivité élevée comme la fumée de silice ou le métakaolin avaient généralement une contribution positive plus importante que celle des poudres à faible réactivité. Les résultats de l’hydratation des MBE ternaires, suivie par la calorimétrie isotherme, n’ont pas montré l’effet synergétique escompté de la combinaison d’une poudre à faible réactivité avec une autre à réactivité élevée dû à l’augmentation de la demande en SP en présence de cette dernière. Une optimisation multiparamétrique a permis de sélectionner des ciments ternaires servis au développement des bétons écologiques présentant les meilleures performances. Finalement, l’utilité de la méthode des MBE dans la prédiction de l’effet des AM sur les bétons a été discutée.
Abstract : The speed with which the world operates today has direct repercussions on everything around us and, in the foreground, on the construction market, where the criteria are more and more demanding such as short construction times, complexity of forms, etc. The use of fluid concretes where rheological properties are well controlled is a key to satisfy these criteria, especially since we are on the threshold of a new era in the construction world including the 3D concrete printing. However, an adequate selection of mineral additives (MA) and chemical admixtures (superplasticizers, SP and viscosity agents, VA) that are used in the design of fluid concretes is a crucial problem. A very extensive experimental program is conducted to shed light on the effect of eight different MA in binary and ternary systems as well as the effect of their interactions with the chemical admixtures (SP and VA) on the properties of concrete equivalent mortars (CEM). Two classes of fluid concretes are investigated in this study, including self-consolidating concrete (SCC) for building constructions and semi-flowable concrete (SFC) for transportation infrastructures. Particular attention is paid to the rheological properties, without neglecting the heat of hydration as well as the mechanical properties. The results showed that it is difficult to generalize on the influence of MA on the properties of CEM. The physical properties of MAs such as fineness, shape or particle size distribution are factors that play an important role in the rheology of fluid concretes. However, the influence of these factors can be masked by the physical and chemical interaction that may occur between the powders and the chemical admixtures used (type of SP in the presence or not of a compatible VA). The particle morphology of MA has a direct effect on the plastic viscosity of CEM. An angular and irregular shape (Ferret factor around 0.4) contributes to increase the plastic viscosity of CEM and a spherical shape (Ferret factor close to 1) contributes to decrease their plastic viscosity. Moreover, the results of the statistical analysis showed that the influence of MA in ternary combination (low-reactivity powder with high-reactivity powder), in the presence of a relatively high water-to-powder ratio (W/P) of 0.45, on the majority of responses is only the sum of the individual effects of these powders. On the other hand, an interaction effect between the powders for some responses began slightly when the W/P was decreased to 0.41. However, in developing 28- and 91-day compressive strengths, high-reactivity powders such as silica fume or metakaolin generally had positive contribution higher than low-reactivity powders. Results of ternary CEM hydration followed by isothermal calorimetry did not show the expected synergistic effect of combining a low-reactivity powder with another with high reactivity due to increased demand in SP in the presence of the latter. A multiparametric optimization allowed selection of ternary cements used to develop ecological concretes with the best performance. Finally, the use of the CEM method in prediction of the effect of AM on concrete was discussed.

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The mortar is a type of adhesive products used in large scale in construction, it is a function of its variety and ease of application . Although industrialized product and endowed with technology in its production is very frequent occurrence of the same pathology , which causes frequent damage and losses in the construction industry. Faced with this real market situation , the technical and scientific study of the effects of the addition of diatomite on the rheological and mechanical behavior of adhesive mortars are needed. This work back as a suggestion the use of diatomite as a mineral additive in formulations of adhesive mortars for partial replacement of cellulose based additives . The choice of using this mineral occurs through physical, chemical and rheological properties that justify its use in this product line , and is a raw material abundant in our region and can thus contribute positively to the minimization of direct costs cellulose -based additives . Industrial adhesive mortar used for comparison , was type AC1 . Formulations of adhesive mortar with diatomite held constant dosed quantities of sand, cement and the water / cement (w / c ) , or adhesive mortar formulations were developed with levels 10, 20, 30 and 40% of diatomite substituting part of the cellulose -based additives . These mortars were subjected to the following tests that define and evaluate the rheological and mechanical behavior of this type of mortar. The results attest the best performance of the adhesive mortar type AC1 with partial replacement of 30 % of the cellulose-based additive for diatomite
As argamassas do tipo colante ? um dos produtos utilizados em grande escala na constru??o civil, isso se d? em fun??o da sua variedade e da facilidade de aplica??o. Embora seja produto industrializado e dotado de tecnologia em sua produ??o ? muito frequente a ocorr?ncia de patologias nas mesmas, o que ocasiona danos e preju?zos frequentes na ind?stria da constru??o civil. Frente a esta situa??o real de mercado, se fazem necess?rios o estudo t?cnico e cient?fico dos efeitos da adi??o de diatomita no comportamento reol?gico e mec?nico de argamassas colantes. Este trabalho tr?s como sugest?o a utiliza??o da diatomita como um aditivo mineral nas formula??es das argamassas colantes em substitui??o parcial dos aditivos a base de celulose. A op??o do uso deste mineral se d? pelas suas propriedades f?sicas, qu?micas e reol?gicas que justificam seu uso nesta linha de produto, al?m de ser uma mat?ria prima abundante em nossa regi?o, podendo desta forma contribuir de maneira positiva para a minimiza??o dos custos diretos com aditivos a base de celulose. A argamassa colante industrial utilizada, para efeito de compara??o, foi a do tipo AC1. As formula??es das argamassas colantes dosadas com diatomita mantiveram constantes as quantidades de cimento, areia e a rela??o ?gua/cimento (a/c), ou seja, foram desenvolvidas formula??es de argamassas colantes com teores 10, 20, 30 e 40% de diatomita em substitui??o parcial dos aditivos a base de celulose. Essas argamassas foram submetidas aos seguintes ensaios que definem e avaliam o comportamento reol?gico e mec?nico deste tipo de argamassa. Os resultados obtidos atestaram o melhor desempenho das argamassas colantes tipo AC1 com substitui??o parcial de 30% do aditivo a base de celulose pela diatomita

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Generally, cellulose ethers improves mortar properties such as water retention, workability and setting time, along with adherence to the substrate. However, a major disadvantage of the addition of cellulose ethers in mortars is the delay in hydration of the cement. In this paper a cellulose phosphate (Cp) was synthesized water soluble and has been evaluated the effect of their incorporation into mortar based on Portland cement. Cellulose phosphate obtained was characterized by spectrophotometry Fourier transform infrared (FTIR), X-ray diffraction (XRD), elemental analysis and scanning electron microscopy (SEM). Mortar compositions were formulated with varying phosphorus content in cellulose and cellulose phosphate concentrations, when used in partial or total replacement of the commercial additive based hydroxyethyl methyl cellulose (HEMC). The mortars formulated with additives were prepared and characterized by: testing in the fresh state (consistency index, water retention, bulk density and air content incorporated) and in the hardened state (absorption by capillarity, density, flexural and compression strength). In mixtures the proportion of sand:cement of 1:5 (v / v) and factor a / c = 1.31 and water were held constant. Overall, the results showed that the celluloses phosphates employed in mortars added acted significantly when partially substituting the commercial additive. With regard to consistency index, water retention and bulk density in the fresh state and absorption by capillarity and bulk density apparent in the hardened state, showed no appreciable differences as compared to the commercial additive. The incorporated air content in the fresh state reduced markedly, but did not affect other properties. The mortars with cellulose phosphate, partially replacing the commercial additive showed an improvement of the properties of flexural strength and compressive strength
Geralmente, ?teres de celulose melhoram as propriedades de argamassas, tais como reten??o de ?gua, trabalhabilidade e o tempo de pega, juntamente com a ades?o ao substrato. No entanto, uma das principais desvantagens da adi??o dos ?teres de celulose nas argamassas ? o retardo na hidrata??o do cimento. Neste trabalho foi sintetizada uma celulose fosfatada (Cp) sol?vel em ?gua e foi avaliado o efeito da sua incorpora??o em argamassa ? base de cimento Portland. A celulose fosfatada obtida foi caracterizada por espectrofotometria de infravermelho por transformada de Fourier (FTIR), difra??o de raios-X (DRX), an?lise elementar, an?lise termogravim?trica (TGA) e microscopia eletr?nica de varredura (MEV). Argamassas com composi??es variando o teor de f?sforo relativamente ? celulose e as concentra??es de celulose fosfatada, quando utilizada em substitui??o parcial ou total do aditivo comercial a base de hidroxietil metil celulose (HEMC). As argamassas formuladas com os aditivos foram preparadas e caracterizadas por: ensaios no estado fresco (?ndice de consist?ncia, reten??o de ?gua, densidade e teor de ar incorporado) e no estado endurecido (absor??o por capilaridade, densidade, resist?ncia ? flex?o e compress?o). Nas misturas a propor??o de areia, cimento e ?gua foram mantidos constantes. De um modo geral, os resultados mostraram que as celuloses fosfatadas empregadas nas argamassas atuaram significativamente quando adicionados parcialmente em substitui??o ao aditivo comercial. No que se refere ao ?ndice de consist?ncia, reten??o de ?gua e densidade de massa no estado fresco e absor??o por capilaridade e densidade de massa aparente no estado endurecido, n?o demonstraram diferen?as apreci?veis comparativamente ao aditivo comercial. O teor de ar incorporado no estado fresco reduziu de forma marcante, mas n?o influenciou as demais propriedades. As argamassas com celulose fosfatada, substituindo parcialmente o aditivo comercial, mostraram uma melhora das propriedades de resist?ncia ? flex?o e de resist?ncia ? compress?o.

Recently, additive manufacturing (AM), or "3D printing," is expanding into civil infrastructure applications, particularly cementitious materials. To ensure the safety, health, and welfare of the public, quality assurance and quality control (QA/QC) methods via standardized testing procedures are of the upmost importance. However, QA/QC methods for these applications have yet to be established. This thesis aims to implement existing ASTM standards to characterize additive manufactured cementitious composites and to gather better information on how to tackle the challenges that are inherent when printing with cementitious materials. In this work, fresh mix properties and hardened concrete properties were investigated using current ASTM standards as a starting point for applying or adapting them for AM applications. Specifically, this project applied existing ASTM standards for fresh mix mortars to measure setting time, flow, and early compressive strength as qualitative indicators of printability, pumpability, and buildability. The fresh mix properties were investigated for 12 different mortar mixes to demonstrate the effect that moisture content, absorption, and sand type can have on these fresh mix properties. The results for setting time and compressive strength demonstrated that there was less variability in the properties when the moisture condition of the aggregate was measured and accounted. Flow was shown to be strongly influenced by the sand type. Additively manufactured mortars were used to print a box in a layer-by-layer process. To evaluate the effect of layering on the flexural strength, three-point bending tests were implemented using four different loading orientations to explore the anisotropic mechanical properties. The observed anisotropic behavior was corroborated with stereo-digital image correlation data showing the stress-strain and load-deflection relationships. Two orientations (A and B) demonstrated brittle behavior while the other two orientations (C and D) experienced quasi-brittle behavior. In addition, setting a minimum unit weight of 132 pcf enabled an analysis of the effect that defects had on the mechanical performance: specimens greater than 132 pcf demonstrated greater and less variable strengths than the specimens less than 132 pcf. The discussion of how defects impacted performance of the different orientations can be valuable when determining how to effectively model, design, and inspect 3D printed structures in the future. The findings of this thesis confirm that existing ASTM standards for mortars can be modified and applied to AM cementitious composites for QA/QC. It is recommended that mixtures used in 3D printing of cementitious composites should design and accommodate the moisture condition of the aggregate to optimize the predictability of the fresh and early-age properties. For the hardened properties, it is recommended that testing procedures such as flexural testing account for anisotropic behavior. Furthermore, for implementation of 3D printed concrete structures, it is highly recommended that design is a function of loading orientation due to the anisotropic properties of the composite.
Master of Science
Recently, additive manufacturing (AM), or "3D printing," is expanding into civil infrastructure applications, specifically cementitious materials such as mortar and concrete. Understanding and predicting the behavior of the materials when using this new technique is vital for quality assurance and quality control (QA/QC). However, standard test methods have yet to be established for this new construction technique. This thesis aims to use existing testing standards to characterize AM cementitious composites and to gather better information on how to tackle the challenges of printing with these materials. In this work, properties before and after the materials hardened were studied by adapting current testing standards. Specifically, this project applied existing testing standards for fresh mix mortars to measure setting time, flow, and early compressive strength. These properties can serve as indicators of specific printing requirements. The fresh mix properties were studied for 12 different mortar mixes to show the effect of moisture content, absorption, and sand type. The results suggest that there was less variability in the properties when the moisture condition and type of the aggregate was accounted. The fresh mix materials were printed in a layer-by-layer process and then hardened in place. The effects of the layers were explored by performing flexure tests using four orientations with respect to how the load was applied to the layers. The observed difference in behavior for the different orientations was supported by digital image correlation data. In addition, an analysis of the effect defects had on the performance was included. Understanding how defects impacted performance can be valuable for effectively designing 3D printed structures in the future. The results of this thesis confirm that existing testing standards for mortars can be adapted and applied to AM cementitious materials for QA/QC. It is recommended that mixtures used in 3D printing of cementitious materials should account for the moisture condition of the aggregate to improve the predictability of the fresh and early-age properties. For the hardened properties, it is recommended that the design is a function of loading orientation due to the difference in behavior for the different orientations of the material.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The mango is one of the most popular fruits in Brazil, and the best know type is Mangifera indica L. The production of this fruit is seasonal and its industrialization has grown in the last years as a means of diminishing loss in the harvest time. The mango processing generates a great amount of residues, around 40 to 60% of the entire amount of raw material. From the residues generated, 12 to 15% is made up of peel and 15 to 20% is seeds. The residues cannot be accumulated indefinitely where they were produced, and are normally discarded with no previous treatment, far from the processing unit. In this sense, the use of the mango seed as a source of cellulose is an alternative in order to diminish the loss and impact on the environment. In this study, the mango seed of the Ubá variety of mangifera indica L. was used as a source of cellulose. The mango seed, originating from a juice factory in the municipality of Araguari-MG, showed a content of cellulose of 55.00% ± 1.0, while the content of Klason lignin was 23.85% ± 0.3. The fibres of the mango seed were used in the production of methylcellulose and the samples were produced by means of heterogeneous methylation using dimethyl sulfate (DMS) and iodomethane as alkylating agents. The methylcelluloses produced were characterized as to their thermal properties by means of scanning exploratory calorimetry (DSC) and thermogravimetric analysis (TGA). The crystalline fraction of the polymers was determined by diffraction of X-rays (DRX), and the substitution degrees (GS) were determined by chemical means. The GS values, determined by chemical means were of 1.35 for MCD and 0.45 for MCI, showing a higher substitution in the synthesis using DMS as methylation agent. Aqueous solutions of methylcellulose, in the concentration of 0.2% m/m and 0.6% m/m (polymer mass/cement mass) were used as an additive in mortar and its effect was assessed, when newly prepared, by means of Consistency Index (CI) tests, density and water retention. After hardened, tests by means of the assessment of potential resistance in adherence and traction (Ra) were carried out. The methylcellulose samples obtained with DMS (MCD) and iodomethane (MCI) as methylate agents, used in the proportion of 0.6% w/w, showed better result; the increase was of 27.75% and 71.54% in the IC and an increase of 23.33% and 26.67% respectively in the Ra, showing that polymers can be used in the production of adhesive mortars.
A manga é uma das frutas mais populares no Brasil, sendo a espécie mais difundida a Mangifera indica L. A produção dessa fruta é sazonal e sua industrialização tem crescido nos últimos anos como forma de diminuir as perdas no período de safra. O processamento da manga gera uma grande quantidade de resíduos, em torno de 40 a 60% de toda a matéria prima. Dos resíduos gerados 12 a 15 % são constituídos de cascas e de 15 a 20% de sementes. Os resíduos não podem ser acumulados indefinidamente no local onde foram produzidos e geralmente são descartados sem um tratamento prévio, longe da unidade processadora. Nesse sentido a utilização do caroço de manga como fonte de celulose se torna uma alternativa para diminuir as perdas e o impacto ambiental. No presente trabalho, o caroço de manga, Mangifera indica L. variedade Ubá, foi utilizado como fonte de celulose. O caroço de manga, proveniente de uma fábrica de suco do município de Araguari-MG, apresentou um teor de celulose de 55,00 % ± 1,0, enquanto o teor de lignina Klason foi de 23,85 % ± 0,3. As fibras do caroço de manga foram utilizadas para produção de metilcelulose e as amostras foram produzidas através da metilação heterogênea, utilizando-se o dimetilsulfato (DMS) e o iodometano como agentes alquilantes. As metilceluloses produzidas foram caracterizadas quanto às propriedades térmicas por calorimetria exploratória de varredura (DSC) e análise termogravimétrica (TGA). A fração cristalina dos polímeros foi determinada por difração de raios-X (DRX), e os graus de substituição (GS) foram determinados por via química. Os valores de GS, determinados por via química, foram de 1,35 para a MCD e 0,45 para a MCI, demonstrando uma maior substituição na síntese utilizando DMS como agente metilante. Soluções aquosas de metilcelulose, na concentração de 0,2 % m/m e 0,6% m/m (massa de polímero/massa de cimento), foram empregadas como aditivo em argamassas e o seu efeito foi avaliado, no estado fresco, através de ensaios de Índice de Consistência (IC), densidade e retenção de água. No estado endurecido, através da resistência potencial de aderência à tração (Ra). As amostras de metilcelulose obtidas com DMS (MCD) e iodometano (MCI) como agentes metilantes, utilizadas na proporção de 0,6% m/m, apresentaram um melhor resultado, sendo que o aumento foi de 27,75 % e 71,54 % no (IC) e um aumento na Ra de 23,33 % e 26,67%, respectivamente, mostrando que os polímeros podem ser empregados na produção de argamassas adesivas.
Doutor em Química

The presents study results of the addition of sulfonated polystyrene, derived from discarded plastic cups as additive in mortars. The mortar were studied with polystyrene content of 0.0, 0.2, 0.6, 1.0 and 1.4% (relative to the mass of cement). CPV - ARI Portland cement and sand washed were used at rate 1:4 by weight. It was determined consistency index, water retention, water absorption, void index, static modulus of elasticity, compressive strength, tensile strength in bending and adhesion. The mortar modified with the additive showed increase in the porosity, tensile strength in bending, adhesion, plastic capacity and water retention. Furthermore the use of polystyrene leads to decrease in the density, the modulus of elasticity and in the capillary water absorption with increasing content of sulfonated polystyrene, which may indicate that even by increasing the number pores in the mortar, the pores are not communicated among themselves and the polymeric film had contributed for the mechanical properties.
O trabalho apresenta resultados do estudo da adição de poliestireno sulfonado, oriundo de copos plásticos descartados, como aditivo em argamassas. Foram analisadas argamassas com os teores de poliestireno de 0,0; 0,2; 0,6; 1,0 e 1,4% em relação à massa de cimento. Foi utilizado o cimento Portland CPV - ARI e areia lavada no traço 1:4 em massa. Para se avaliar a influência da adição de poliestireno nas propriedades das argamassas determinouse índice de consistência, retenção de água, absorção de água, índice de vazios, módulo estático de elasticidade, resistência à compressão, resistência à tração na flexão e resistência potencial de aderência à tração. Em relação à argamassa sem aditivo a argamassa modificada demonstrou aumento na resistência de aderência à tração, resistência a tração na flexão, porosidade, absorção de água, retenção de água e consistência. No entanto, o aumento do teor de poliestireno sulfonado leva à uma redução do módulo de elasticidade, da massa específica e da absorção de água por capilaridade, o que pode indicar que mesmo aumentando o número de poros na argamassa, estes poros não são intercomunicáveis e o filme polimérico contribui para o incremento das propriedades mecânicas, especialmente à tração.
Mestre em Engenharia Civil

碩士
國立臺北科技大學
土木工程系土木與防災碩士班
106
Graphite materials are now widely used in everyday life. With the development of nano-graphene materials, these materials have become one of the hottest and leading. However, there are few related studies on applying these materials to concrete. This study used graphene-based materials, such as graphite powder, graphene, 2 % graphene oxide, and 10 % graphene oxide, in cement mortar. The materials’ dispersion and the engineering properties of cement mortar with additions graphene-based materials were been investigated. First, consider the use of four different water-reducing levels (18 %, 27 %, 28 %, 30 %) polycarboxylate superplasticizers to investigate the dispersion of graphite materials. Various graphite materials were added to the cement mortar with cement weight percentage (0~0.4 %), and the properties of fresh mortar, mechanical strength, thermoelectric properties and microstructure were tested to explore the influence of graphite materials on the engineering properties of cement mortar. From the test results, the absorbance measured by the ultraviolet spectrophotometer (UV) could be as a dispersion indicator for the graphene-based material in the cement mortar solution. When the superplasticizer is used as the dispersing agents for the graphene-based materials, its water-reducing rate is not positively correlated with the dispersion of the graphene-based material. The higher the number of carboxylate ions in the superplasticizer, the better the dispersion effect on graphene. When the amount of the superplasticizer is increased from 0 times to 6.6 times by the graphite material, the absorbance changes between 0.52 and 1.93 A.U. Among them, the dispersion degree is the best when the amount of the superplasticizer is 4 times by the graphite material. There is a most obvious improvement made by 10% graphene oxide on the mechanical strength of cement mortar. When the addition rate was increased from 0% to 0.4%, the compressive strength and flexural strength of the cement mortar varied from 305 to 418 kgf/cm2 and 56 to 75 kgf/cm2 at 28 days age, respectively. For the samples mentioned above, the addition rate of 0.15% is the best. There is great influence of 2% graphene oxide on the conductivity and thermal conductivity of cement mortar. When the addition rate is 0% to 0.4%, the conductivity of the cement mortar varies from 34 to 106 S/m, and its thermal conductivity is between 0.97 and 1.63 W/mK at 28 days age. The addition of graphene oxide can improve the electrical and thermal conductivity of cement mortar. When the addition rate is fixed at 0.15 %, the total pore volume of the cement mortar to which graphite powder, graphene, 2% graphene oxide, and 10% graphene oxide are added is 0.136, 0.119, 0.106, and 0.102 ml/g, respectively. The control group was 0.132 ml/g. Graphite powder may increase the amount of pores, while both graphene and graphene oxide reduce the pore volume. The phenomenon mentioned above is most obvious with 10 % graphene oxide, which can be reduced by about 30 %. The scanning Electron Microscopy test results show that the addition of graphene-based materials can not only effectively fill the pores of the mortar, but also make the cement mortar denser. It can also bond with the hydration product to increase the nucleating point of the hydration product and promote the hydration reaction

In the present scenario where the constructions are increasing, the need to find a supplementary cementing material for the improvement of strength and which has less environmental effects is of great significance. Ureolytic bacteria are the ones which can improve the strength of cement mortar by the precipitation of calcium carbonate in the presence of urea and a calcium source. In the present study Bacillus sphaericus is used to check its applicability in this regard. Various tests like consistency and initial setting time are done to find out the effect of bacterial solution on cement. Tests such as compression strength and sorptivity test are used in the present study to identify the variation in the mechanical properties of cement mortar. To know the mineralogy and morphology of the calcium carbonate precipitated by the bacteria XRD and FESEM analysis are carried out. Compressive strength (at 7-day and at 28-day) of mortar cube found to be increasing with the increase of bacteria concentration up to 107 cells/ml The optimum doses of bacteria found to increase the average compressive strength by 58% (at 7-day) and 23% (at 28-day) over the control specimen. The more increase in strength after 7 day curing may be due to the presence of nutrient medium and it getting depleted as it reaches 28 days and causing death of bacteria The minimum cumulative water absorption is obtained for a cell concentration of 109 cells/ml The mineralogy and morphology of the calcium carbonate precipitated by the bacteria test was able to confirm that the bacterially precipitated calcium carbonate is calcite and is having lamellar rhombohedra or hexagon shape

碩士
國立臺灣科技大學
營建工程系
92
Admixtures are crucial materials during the procedure of high performance concrete research and development. Among these materials, pozzolanic material plays an important role. Generally, using fly ash, slag, silica fume etc. to improve consolidation and durability of concrete. Owing to the innovation of science and technology, materials head to nanoscale. Lots of reports reveal that nanomaterial science concept must to be considered when study the properties of concrete and enhance the function of concrete. This research chooses pastes as well as mortars of 0.45, 0.55 and 0.65, W/C ratio as control group. Investigating the effects of pastes and mortars with various types of nanoscale pozzolanic materials under different addition ratio. Including permeability, setting time, flow value, compressive strength; resist coefficient, ultrasonic velocity and micro analysis. The study results show that W/C ratio is form high to low as strength from small to large, permeability form high to low. Furthermore, adding zero-dimentional nanomaterials perform better characteristics. In aspect of compressive strength, increasing about 37.8% while adding 0.6% nano silica powder in paste; increasing about 18.6% while adding 0.4% nano silica powder in mortar. In aspect of permeability, increasing about 49.9% while adding 0.4% nano silica plate in paste; increasing about 27.5% while adding 0.4% nano silica plate in mortar. After adding pozzolanic materials, total cementitious quantity increases, so strength development better than control group. Pozzolanic reaction becomes fast when materials reach to nanoscale. One C-S-H colloid produces, the other porosity becomes smaller, make high compressive strength and law permeability coefficient. Resist coefficient and ultrasonic velocity of zero-dimensional nanomaterial added greater than control group. However, flow value and setting time decrease as increasing zero-dimensional nanomaterial. Because nano scale material absorbs more water and reacts rapidly. Hence, shorter setting time and smaller flow value present worse workability.

碩士
國立臺灣科技大學
營建工程系
106
This study investigated the engineering properties development of hardened paste and mortar using class F fly ash to partially replace cement and addition of sodium silicate to partially replace mixing water. Experimental variables included three different water-binder ratios (0.3, 0.4, 0.5), four different fly ash substitutions (0%, 10%, 30%, and 50%), and three different amount of sodium silicate (0%, 5%, and 10%) were observed. The fresh properties including workability, setting time, and pH value, then the hardened properties including compressive strength, drying shrinkage, ultrasonic pulse velocity (UPV), dynamic Young’s modulus, dynamic shear modulus, and dynamic Poisson’s ratio were examined through in this study. The results showed that the application of fly ash improved the engineering properties of paste and mortar for the fly ash substitution up to 30%. At the early age, the strength decreased with the increase of fly ash substitutions due to the low hydration rate using the fly ash. However, the strengths of all the paste and mortar specimens increased by about 20% using the fly ash replacement up to 30% compared with that of the control set at the age of 56 days. The application of sodium silicate did not affect the engineering properties. On the contrary, it reduced the engineering properties. It can be concluded that the presence of sodium silicate did not activate the pozzolanic reaction of fly ash as expected.

Crack formation under tensile forces is a major weakness of concrete. Cracks make concrete vulnerable to the extreme environment due to the ingress of water and harmful compounds from the surrounding environment. Conventional methods of crack repairing are expensive and time consuming. It is estimated that in Europe, cost related to repair works is half of the annual construction budget and the US has average annual maintenance cost for existing bridges through the year is estimated to $5.2 billion. To overcome this problem, a self-healing concrete is produced based on the application of mineral producing alkaliphilic Bacillus Subtilis (strain 168) bacteria. Metabolic activities of these bacteria on calcium-based nutrients results in precipitation of calcium carbonate, which helps to repair concrete cracks. In bacteria based self-healing concrete, the bacteria are protected in the dense cementitious matrix by encapsulating them in “bacteria-carriers”. However, the presently available bacteria-carriers are not always suitable for concrete because of their complex manufacturing procedures or high cost. With the aim to develop a more suitable bacteria-carrier, in this study feasibility of cellulose fiber as a novel bacteria-carrier for self-healing mortar is investigated. Cellulose fibers compared to other bacteria-carriers can serve the dual purpose of arresting cracks and at the same time be a bacteria-carrier in large scale concrete construction. Two types of bacterial mortar by using cellulose fiber as a carrier was prepared. For one type, nutrients were added inside the mortar mix, while for the other, nutrients were added into the curing water. The two types of composites; control and cellulose fiber reinforced concrete (CeFRC) have also been investigated for autogenous healing of concrete. The crack healing efficiency of bacterial mortars was investigated using image analysis and ultrasonic pulse velocity (UPV) test and compared with unreinforced and control cellulose fiber mortars. Variation in compressive strength for all mixes compared to control mortar is also presented in this thesis. Research shows that self-sealing mortar using cellulose fiber as a bacteria-carrier result in maximum self-healing as compared to other mixes. This study also aims to evaluate the self-healing potential and water permeability of CeFRC. Compressive strength and flexural tests were also performed to evaluate the mechanical properties of the composites. Water permeability test was used to evaluate the coefficient of permeability and the self-healing performance was investigated by using UPV and a patented self-healing test. The results indicate that the water permeability coefficient decreased by 42% (+15% or -21%) whereas the healing ratio increased at a higher rate for the initial days of healing when cellulose fibers were added in the concrete. CeFRC also results in a 7.8% increase in flexural strength.
Graduate
2020-09-13

碩士
國立臺北科技大學
土木與防災研究所
97
The number of skyscrapers is increasing day after day with the fast development of economy in recent years. Therefore, concrete still remains a major part no matter in primary or secondary structures. The use of concrete is always measured in hundreds or even thousands of tons. With such a massive quantity, the quality of concrete determines the safety of a building, and the compression strength of concrete is a crucial index for direct reference. Standard mortar compression strength test specimens were prepared as per CNS61 for Type I Portland Cement. The specimens are cubes of 5cm×5cm×5cm. The specimens were prepared with equal amount of standard sand and water, and part of cement was replaced with fly ash and GGBF slag. The additions of fly ash and slag are 10%, 20%, 30% and 40% of the bonding material for different specimens in 7 days, 28 days and 90 days of age. From these specimens, the optimized addition of fly ash and GGBF slag was found for improvement of mortar compression strength. In addition, cylindrical specimens were prepared as per CNS 1239 for compression tests. The cylinders were 15cm×30cm in dimension with a strength of 280 . Fly ash and GGBF slag equivalent to 10%, 20% and 30% of amount of bonding material were used to replace cement. Specimens of 20 days and 90 days of age were used for concrete compression strength test. The results from mortar and cement tests were made available for comparing if the optimized additions of fly ash and GGBF slag are close. Standard mortar strength test was used to replace concrete compression test in the study for the optimized addition of fly ash and GGBF slag. The results show that the optimized addition of fly ash and GGBF slag in mortars and that in concrete are quite similar.

Бетонування при негативних температурах пов'язане з ризиками розморожування бетону. При температурі + 5 ° С і нижче, волога, що знаходиться в розчині, кристалізується і припиняється процес гідратації цементу. Крім того, вода при кристалізації (замерзання) збільшується в об'ємі, і при розширенні розриває існуючі структурні зв'язки, які при відтаванні вже не відновлюються. Модифікований розчин пришвидшує закінчення термінів будівельних робіт за рахунок покращення текучості та пластичності, що дає більшу зручність укладання бетону.
Concreting at low temperatures is associated with the risks of defrosting concrete. At a temperature of + 5 ° C and lower, the moisture in the solution crystallizes and the process of cement hydration stops. In addition, water during crystallization (freezing) increases in volume, and when expanded, it breaks existing structural bonds, which, when thawing, are no longer restored. The modified mortar accelerates the completion of construction works due to improved fluidity and ductility, and gives greater convenience in laying concrete.
ВСТУП...5 Розділ 1. ВПЛИВ СИНТЕТИЧНИХ РЕЧОВИН НА ВЛАСТИВОСТІ БЕТОНУ 1.1 Загальні положення…7 1.2 Причини зниження морозостійкості бетону…9 1.3 Підвищення морозостійкості бетону…11 1.4 Властивості добавок-модифікаторів…13 1.5 Принципи дії проти морозних добавок…18 Розділ 2. ВПЛИВ МОРОЗОСТІЙКИХ ДОБАВОК НА БУДІВЕЛЬНОТЕХНІЧНІ ВЛАСТИВОСТІ БЕТОНУ 2.1Випробування бетонного розчину на зручноукладність …21 2.2 Виготовлення зразків бетону (бетонних кубиків 100х100х100мм) ... 24 2.3 Випробування зразків бетону на морозостійкість… 26 2.4Випробування на міцність гідравлічним пресом... 29 2.5Дослідження пористості бетону…31 Розділ 3. РЕЗУЛЬТАТИ ДОСЛІДЖЕНЬ БЕТОНУ 3.1Випробування бетонного розчину на зручноукладність… 33 3.2 Випробування на міцність гідравлічним пресом… 35 3.3 Випробування на морозостійкість… 38 3.4 Результати досліджень пористості…40 Розділ 4. ОБГРУНТУВАННЯ ЕКОНОМІЧНОЇ ЕФЕКТИВНОСТІ ДОСЛІДЖЕНЬ 4.1 Економічна ефективність добавок-модифікаторів…42 Розділ 5. ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ 5.1.1 Закон України "Про охорону праці"…44 5.1.2 Заходи безпеки при роботі з добавками…45 5.1.3. Мікроклімат робочої зони…46 5.2 Безпека в надзвичайних ситуаціях...47 5.2.1 Організація цивільного захисту на промислових об’єктах будівельної галуз...47 ЗАГАЛЬНІ ВИСНОВКИ …50 БІБЛІОГРАФІЯ ...51