La investigación actual se enfoca en evaluar cómo afecta el uso de Nanotubos de Grafeno y el Sistema SNS 360 al concreto estructural con resistencia de 21Mpa. Utilizamos una metodología cuantitativa de carácter experimental, considerando como variables independientes a los Nanotubos de Grafeno y el Sistema SNS 360, y como variables intervinientes las propiedades constituyentes propias del concreto. La muestra analizada incluye una mezcla de concreto estándar y otra con nano-adiciones, sumando un total de 160 prototipos: 140 cilíndricos y 20 prismáticos. Los ensayos realizados abarcan determinación del f’c, tracción y flexión en distintos intervalos: 3, 7, 14 y 28 días. Se experimentó con dosificaciones de MWCNT de 0.10%, 0.25% y 0.05%, añadiendo 1% y 2% de SNS 360 en cada caso. Los resultados indican que la dosificación de 0.05% de MWCNT combinado con 2% NPF ofrece las mejores prestaciones en el concreto. Algunos parámetros obtenidos son: asentamiento de 3.8”, peso unitario de 2321 kg/cm3, contenido de aire del 1.8%, y tiempo de fraguado de 125 min. A los 28 días, el f’c alcanzó 330 kg/cm2, la tracción fue de 27 kg/cm2, y la flexión llegó a 64 kg/cm2. En cuanto al desgaste, superó en 0.078% al diseño estándar, y la permeabilidad mostró una penetración máxima de 19.29 mm. El costo por m³ es de S/ 991.71, indica un aumento del 33.4% en relación con el concreto convencional. / The current research focuses on evaluating how the use of Graphene Nanotubes and the SNS 360 System affects structural concrete with a strength of 21 MPa. We use a quantitative methodology of an experimental nature, considering as independent variables the Graphene Nanotubes and the SNS 360 System, and as intervening variables the intrinsic constituent properties of the concrete. The analyzed sample comprises a standard concrete mix and another with nano-additives, totaling 160 prototypes: 140 cylindrical and 20 prismatic. Tests were conducted on compression, tension, and bending resistance at different intervals: 3, 7, 14, and 28 days. We experimented with MWCNT dosages of 0.10%, 0.25%, and 0.05%, adding 1% and 2% of SNS 360 in each instance. The findings suggest that a dosage of 0.05% MWCNT combined with 2% NPF provides the best performance in concrete. Notable data includes a settlement of 3.8”, a unit weight of 2321 kg/cm3, an air content of 1.8%, and a setting time of 125 min. At 28 days, the compression strength reached 330 kg/cm2, tension stood at 27 kg/cm2, and bending achieved 64 kg/cm2. Regarding wear, it exceeded the standard design by 0.078%, and permeability showed a maximum penetration of 19.29 mm. The cost per m³ is S/ 991.71, marking an increase of 33.4% compared to conventional concrete.

La presente investigación tiene como objetivo general comparar cuál de las dos fibras tanto CFRP (polímero reforzado con fibra de carbono) o GFRP (polímero reforzado con fibra de vidrio) sería la más adecuada para el incremento de la resistencia de las columnas y vigas antes sismos de magnitudes 8.1 y 6.6 en la escala de Richter, necesario para poner en servicio la I.E N°440 Las Flores de la Pradera, que cuenta con 3 pabellones de las cuales el pabellón A-A, B-B son de un nivel con un área de 189.96m2 (7.90m x 24.01m), de 200.41m2 (7.90m x 25.37m), el pabellón C-C es de dos niveles de 36.46m2 (5.58m x 6.34m). El ser aplicadas en las infraestructuras esenciales que han logrado brindar rigidez, seguridad, durabilidad, eficacia, pero frente a la postura del tiempo útil o limitaciones de funciones extremas que han llegado a poner en riesgo su estabilidad. Los polímeros reforzados con fibra de carbono y vidrio han sido un material de solución esencial, definiéndola como una técnica restauradora que, junto a sus propiedades, características y su uso que se han dado en diferentes Áreas de Infraestructuras. Finalmente, se llegó a concluir en la investigación que cumplió el incremento de las resistencias de las vigas a flexión y corte demostrando como el reforzamiento estructural con los polímeros reforzados más adecuado que cual otro material y lo más esencial es que no modifica la estética de la arquitectura en gran magnitud. Pero lo más con una diferencia de que la fibra de carbono (CFRP) no requiere tantas capas como la fibra de vidrio ya que tiene un mejor desempeño en deformación vs esfuerzo a tensión. / The general objective of this research is to compare which of the two fibers, CFRP (carbon fiber reinforced polymer) or GFRP (glass fiber reinforced polymer), would be the most suitable for increasing the resistance of columns and beams before earthquakes. of magnitudes 8.1 and 6.6 on the Richter scale, necessary to put into service the I.E N ° 440 Las Flores de la Pradera, which has 3 pavilions of which pavilion A-A, B-B are one level with an area of 189.96m2 (7.90m x 24.01m), 200.41m2 (7.90m x 25.37m), pavilion C-C has two levels of 36.46m2 (5.58m x 6.34m). Being applied in essential infrastructures that have managed to provide rigidity, security, durability, efficiency, but in the face of the useful time posture or limitations of extreme functions that have come to put their stability at risk. Carbon and glass fiber reinforced polymers have been an essential solution material, defining it as a restorative technique that, together with its properties, characteristics and its use that have been given in different Infrastructure Areas. Finally, it was concluded in the investigation that the increase in the resistance of the beams to bending and shear was achieved, demonstrating how the structural reinforcement with reinforced polymers is more adequate than any other material and the most essential thing is that it does not modify the aesthetics of the structure. architecture in great magnitude. But the most important difference is that carbon fiber (CFRP) does not require as many layers as fiberglass since it has a better performance in deformation vs. tensile stress.

Este trabajo experimental propone una solución sostenible para la construcción mediante el uso de ladrillos hechos de micelio fúngico y aserrín. La idea surge del problema ambiental que enfrenta el mundo debido a la explotación de materias primas no renovables para la fabricación de materiales de construcción convencionales. En este estudio, el micelio de Pleurotus Ostreatus se mezcló con tres sustratos de diferentes granulometrías: aserrín (MA), virutas de madera (MB) y una mezcla de aserrín y virutas (MC), en proporciones de 10% de micelio y 90% de sustrato. Después de dejar la mezcla en condiciones húmedas durante unos 30 días para permitir un crecimiento óptimo del micelio, se extrajo del molde como un solo bloque sólido y se sometió a pruebas físicas y mecánicas. Los resultados de estos ensayos arrojaron una resistencia a la compresión máxima de 2.81 kg/cm2 perteneciente a la MC y una mínima de 2.38 kg/cm2 para la MA; un módulo de rotura máximo de 3.53 kg/cm2 perteneciente a la MC y un mínimo de 2.59 kg/cm2 para la MA; una densidad de 0.08 g/cm3 para a la MA, 0.15 g/cm3 para la MB y 0.19 g/cm3 para la MC; en absorción se obtuvo un 63.95% para la MA, 30.11% para la MB y 15.4% para la MC; respecto al análisis de costos de producción se halló que es un 28% más barato que un ladrillo convencional de arcilla y un 37% más barato que un ladrillo casetón de tecnopor. En conclusión, este estudio demuestra que el uso de ladrillos hechos a base de micelio fúngico y aserrín podría ser una alternativa sostenible y rentable para el sector construcción.

La presente investigación tiene como objetivo evaluar la influencia de la incorporación de agregado grueso reciclado (AGR) y cenizas de aserrín (CDA) en la elaboración de adoquines de concreto para tránsito ligero, para ello primero se realizó la caracterización de los agregados naturales y reciclado y se clasificó las cenizas de aserrín; posteriormente como primera etapa de demostración se determinó el porcentaje óptimo de cenizas, para ello se realizó el diseño de mezcla para la muestra patrón y con adiciones de 5%, 10% y 15% de CDA, de donde mediante los ensayos físico mecánicos se obtuvo que el porcentaje óptimo es el 5%, dado que mejoran las propiedades de los adoquines, luego se realizó la segunda etapa donde se elaboraron especímenes con el porcentaje óptimo de ceniza determinado y el 100% de agregado grueso reciclado, a los cuales como en la primera etapa se le realizó los mismos ensayos donde se determinó que la incorporación del 100% de AGR hace que disminuya la resistencia a la compresión y las otras propiedades se mantienen dentro de los parámetros permitidos. / The objective of this research is to evaluate the influence of the incorporation of recycled coarse aggregate (AGR) and sawdust ash (CDA) in the elaboration of concrete paving stones for light traffic, for which the characterization of natural and recycled aggregates was first carried out. and sawdust ash was classified; Subsequently, as the first demonstration stage, the optimum percentage of ashes will be reduced, for which the mixture design was carried out for the standard sample and with additions of 5%, 10% and 15% of CDA, from which, through the physical-mechanical tests, it was obtained. that the optimal percentage is 5%, since the properties of the paving stones improve, then the second stage was carried out where specimens were made with the optimal percentage of determined ash and 100% recycled coarse aggregate, to which, as in the In the first stage, the same tests were carried out where it was established that the incorporation of 100% of AGR causes the compressive strength to decrease and the other properties to remain within the permitted parameters.

Thesis (MEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The suitability of local construction materials for construction purposes is governed by several rock mechanical properties. Strength, durability, performance and petrography of aggregates all influence the decisions engineers make in deciding if the aggregate is suitable and sustainable throughout the lifetime of a structure. This thesis investigates these properties by combining engineering, chemistry and geological disciplines to make informed decisions. The pertaining project for which the research was conducted is the construction of the gravimeter vault at the Matjiesfontein Geodesy and Earth Observation Observatory (MGO) although the research acquired can be used for other projects of a similar nature and other outbuildings at the MGO. Material at and around the site were tested for strength and durability according to certain South African National Standards (SANS). Slake durability was tested as certain rock types tend to slake when exposed to the atmosphere such as tillite of the Dwyka formation and shale of the Karoo Supergroup. Concrete cube strength was determined on cubes containing crushed rock from Matjiesfontein as well as river sand. Cube strength was conducted to analyse performance and to establish a mix design that would be sustainable throughout the lifetime of the project. Petrographic examination using Powder X-ray diffraction (PXRD), X-ray fluorescence (XRF), Scanning Electron Microscopy (SEM) and inspection under a petrographic microscope were conducted. These methods were used to determine if a risk exists for alkali-silica reactivity (ASR) in concrete when the rock types are used as aggregate, particularly if high quartz-bearing rock types such as quartzite of the Table Mountain group were to be used as coarse aggregate. Inspection of thin sections for strained quartz under a petrographic microscope and SEM imaging were important in determining if ASR may occur. The gravimeter vault was constructed using materials sourced mainly from Laingsburg. Tillite satisfied all tests and analyses conducted during the research, making it more suitable for construction than the other materials from Matjiesfontein. The slake durability test indicates that tillite is nearly as durable as quartzite, which is considered the most durable rock type at Matjiesfontein. This is due to atmospheric conditions in the Karoo being very dry with low humidity in comparison to the coast where slaking is known to occur. Slaking properties were most prominent for shale at Matjiesfontein and if excavated, it is recommended to cover the exposed shale with a layer of asphalt or cement to prevent slaking. The 10% fines aggregate crushing test (10%FACT) value for tillite was over the 210 kN prerequisite and the wet-to-dry ratio over 75% making it suitable for road construction according to the 10%FACT. All cube tests reached the desired 40 MPa prerequisite although the mixtures containing local river sand were unworkable. Unlike quartzite and quartzitic sandstone from Matjiesfontein, tillite is low in quartz and has minimal strained quartz. Therefore, no risk exists for ASR if tillite were to be used as aggregate in concrete. / AFRIKAANSE OPSOMMING: Die geskiktheid van plaaslike konstruksiemateriale vir konstruksiedoeleindes word deur sekere rots meganiese eienskappe beïnvloed. Sterkte, duursaamheid, volhoubaarheid en petrografie van aggregaat beïnvloed die besluite wat ingenieurs moet neem sodat die aggregaat aan standaarde voldoen en gedurende die leeftyd van ‘n struktuur volhoubaar is. Hierdie tesis ondersoek die genoemde eienskappe deur ingenieurs-, chemiese- en geologiese dissiplines te kombineer. Die voorgenome projek, waarvoor die navorsing ter sprake is, is vir die konstruksie van die gravimeterkluis by die “Matjiesfontein Geodesy and Earth Observation Observatory (MGO)”, alhoewel die navorsing ook gebruik kan word vir soortgelyke projekte, sowel as die konstruksie van die res van die geboue by die MGO. Materiale van die terrein en die omgewing is volgens sekere Suid-Afrikaanse kodes vir sterkte en duursaamheid getoets. Die blusbaarheid van materiale is getoets omdat sekere materiale, soos tilliet van die Dwyka-formasie en skalie van die Karoo Supergroep blus wanneer dit aan die atmosfeer blootgestel word. Die betonsterkte van kubusse, waarin plaaslike gesteentes en riviersand van Matjiesfontein vir aggregaat gebruik is, is bepaal. Die kubusse is getoets om die sterkte daarvan te analiseer en om ‘n betonmengsel, wat tydens die leeftyd van die projek volhoubaar is, daar te stel. Petrografiese eksaminering deur X-straal difraksie (XRD), X-straal fluoressensie (XRF), Skandeerelektronmikroskopie (SEM) en inspeksie onder ‘n petrografiese mikroskoop is gedoen. Met die doel om die petrografiese samestelling van materiale van Matjiesfontein te bepaal, is hierdie metodes gevolg om te uit te vind of daar ‘n risiko vir alkalie-silikaat reaksies (ASR) bestaan, as die gesteentes in beton gebruik word. Veral gesteentes met ‘n hoë hoeveelheid kwarts, soos kwartsiet van die Tafelberg-groep, is hier ter sprake. Inspeksie van dunsnitte vir gespanne kwarts onder ‘n petrografiese mikroskoop en SEM was belangrik om die risiko vir ASR te bepaal. Die gravimeterkluis is hoofsaaklik met materiale afkomstig van Laingsburg gebou. In vergelyking met die ander gesteentes by Matjiesfontein is tilliet, volgens alle toetsparameters, die mees geskikte gesteente vir konstruksiedoeleindes. Die blusbaarheid van tilliet vergelyk goed met kwartsiet, wat as die sterkste en duursaamste gesteente by Matjiesfontein, beskou word. Die rede hiervoor is die atmosferiese toestande wat baie droër is, asook die laer humiditeit in die Karoo, in vergelyking met gebiede nader aan die kus waar blusting meer algemeen voorkom. Die blusbaarheid van skalie by Matjiesfontein kom algemeen voor. As daar dus uitgrawing in hierdie gebied plaasvind, word dit aanbeveel dat ‘n laag sement of asfalt oorgegooi word om die blusting te verhoed. Die 10%FACT waarde vir tilliet was bo die vereiste 210 kN, asook bo die 75% nat-teenoor-droog-verhouding en daarom is dit volgens die 10%FACT-toets as padboumateriaal geskik. Alhoewel mengsels, wat plaaslike riviersand bevat het, onwerkbaar was, het alle toetsmonsters (kubusse) die vereiste 40 MPa- sterkte bereik. In vergelyking met kwartsiet en kwarsitiese sandsteen, bevat tilliet min kwarts en ook minimale gespanne kwarts. Daar bestaan dus geen risiko vir ASR indien tilliet van Matjiesfontien in die beton gebruik word nie.

This thesis argues that early nineteenth-century domestic architecture along Indiana's eastern National Road (Wayne, Henry and Hancock Counties) was a product of the available local materials, not a product of cultural influences traveling along the Road. While the first chapter drives in this point, the second and third chapters describe the local materials (builders and carpenters, wood, saw-mills, clay, brickmaking and limestone), and explain construction techniques in a series of case study buildings. The thesis concludes by not only confirming the proposition, but also by making a few conclusions regarding early nineteenth-century construction methods. / Department of Architecture

Cellulose Nanocrystals have been used in a wide range of applications including cement composites as a strength enhancer. This work analyses the use of CNC from several sources and production methods, and their effects on rheology and hydration of pastes made using different cement types with different compositions. Cement Types I/II and V were used to prepare pastes with different water to cement ratios (w/c) and measure the changes in rheology upon CNC addition. The presence of tricalcium aluminate (cement chemistry denotes as C3A) made a difference in the magnitude of CNC effects. At dosages under 0.5vol% to dry cement, CNC reduced the yield stress up to 50% the control value. Pastes with more C¡A reduced yield stress over a wider range of CNC dosages. CNC also increased yield stress of pastes with dosages above 0.5%, twice the control value for pastes with high C3A content at 1.5% CNC and up to 20 times for pastes without C3A at the same dosage.<br>All the CNCs used were characterized in length, aspect ratio, and zeta potential to identify a definitive factor that governs the effect in the rheology of cement pastes. However, no definitive evidence was found that any of these characteristics dominated the measured effects.<br>The CNC dosage at which the maximum yield stress reduction occurred increased with the amount of water used in the paste preparation, which provides evidence of the dominance of the water to cement ratio in the rheological impact of CNC.<br>14<br>Isothermal calorimetry showed that CNC cause concerning retardation effects in cement hydration. CNC slurries were then tested for sugars and other carbohydrates that could cause the aforementioned effect, then slurries were filtered, and impurities were detected in the filtrate, these impurities were quantified and characterized, however, the retardation appeared to be unaffected by the amount of the species detected, suggesting that the crystal chemistry, which is a consequence of the production method, is responsible of this retardation.<br>This work explores the benefits and drawbacks of the use of CNC in cement composites by individually approaching rheology and heat of hydration on a range of physical and chemical tests to build a better understanding of the observed effects.<br>Understanding the effect of CNCs on cement paste rheology can provide insights for future work of CNCs applications in cement composites.

Atualmente, o reaproveitamento de resíduos resultantes de atividades industriais vem se tornando um dos pontos mais importantes na melhoria dos aspectos produtivos, como também na minimização de problemas ambientais decorrentes da forma de produção e do descarte final do resíduo gerado no decorrer do processo de produção. Desta maneira, as indústrias estão buscando implantar um sistema de gestão ambiental (SGA), no qual o resíduo, anteriormente descartado, passa a ser considerado matéria prima para a fabricação de novos materiais. Dentro deste enfoque, e considerando os impactos gerados pelas indústrias de papel e celulose, estudos que visam demonstrar o potencial de utilização do lodo residual gerado durante a produção de papel na indústria Votorantim Celulose e Papel (VCP), município de Jacareí, SP-Brasil, têm sido desenvolvidos, por meio de uma parceria de indústria e universidades (UNESP - Bauru e USP - São Carlos). Após análises químicas e toxicológicas do lodo residual, obteve-se uma composição de aproximadamente 58,9% de fibras, sendo classificado como Classe II, segundo a NBR 10.004/87. Para avaliar o seu potencial de utilização em materiais de construção, foram confeccionados tijolos de adobe com o solo arenoso proveniente do município de Bauru, SP, nos traços 0%, 10%, 15%, 20%, 25%, 30% e 40% em volume de resíduo. Foram realizados diversos ensaios para caracterização dos tijolos (retração, absorção de água e resistência à compressão simples), bem como ensaios de intemperismo, gotejamento, verificação da ação do fogo (perda de massa, propagação das chamas e ensaio de incombustibilidade dos materiais de construção), como também a obtenção de suas características térmicas e acústicas. Com os resultados dos ensaios, foi realizada uma análise geral, por meio da interação dos melhores valores encontrados e, assim, escolhido o traço numa faixa de 20% a 25% de resíduo. Os resultados demonstraram a viabilidade do uso do resíduo em tijolos de adobe, conferindo aos mesmo bons níveis de resistência, manuseio, leveza e durabilidade. / Nowadays, reuse of residues from industrial activities is one of the most important aspects in productivity improvement, as well as, minimization of environmental problems originated from production way and residue disposal during the productive process. Industries are requesting and Environmental Management System (SGA), in which residues, formerly discarded, began to be considered raw materials for production of new materials. In this context and considering impacts generated by paper and cellulose manufacturing, studies have been developed, aiming to demonstrate potential use of residual mud generated during paper production in Votorantin Cellulose and Paper Industry (VCP), located in Jacareí, São Paulo State, Brazil, through a partnership between this industry and universities (UNESP - Bauru and USP - São Carlos). After chemical and toxicological analyses of the residual mud, a composition of aproximately 58,9% of fibres was obtained and classified as Class II acording to NBR 10.004/87. For evaluating its potential use in buildings, adobe bricks were made with sandy soil from Bauru (São Paulo State), considering 0% (witness), 10%, 15%, 20%, 25%, 30% and 40% of residuary volume. Several rehearsals were carried out for brick characterization (retraction, water absorption and resistance to simple compression), and to verify intemperism, leak and fire action (mass loss, flame propagation and fireproof rehearsals), as well as thermal and acoustic characteristics (qualities). A general analysis interacting all values obtained indicated the percentage of residuary volume, in the range of 20% to 25% as the best condition. The results demonstrated viability of use of paper and cellulose residual mud in adobe bricks manufacturing, since they presented good levels of resistance, handling, lightness and durability.

abstract: Being a remarkably versatile and inexpensive building material, concrete has found tremendous use in development of modern infrastructure and is the most widely used material in the world. Extensive research in the field of concrete has led to the development of a wide array of concretes with applications ranging from building of skyscrapers to paving of highways. These varied applications require special cementitious composites which can satisfy the demand for enhanced functionalities such as high strength, high durability and improved thermal characteristics among others. The current study focuses on the fundamental understanding of such functional composites, from their microstructural design to macro-scale application. More specifically, this study investigates three different categories of functional cementitious composites. First, it discusses the differences between cementitious systems containing interground and blended limestone with and without alumina. The interground systems are found to outperform the blended systems due to differential grinding of limestone. A novel approach to deduce the particle size distribution of limestone and cement in the interground systems is proposed. Secondly, the study delves into the realm of ultra-high performance concrete, a novel material which possesses extremely high compressive-, tensile- and flexural-strength and service life as compared to regular concrete. The study presents a novel first principles-based paradigm to design economical ultra-high performance concretes using locally available materials. In the final part, the study addresses the thermal benefits of a novel type of concrete containing phase change materials. A software package was designed to perform numerical simulations to analyze temperature profiles and thermal stresses in concrete structures containing PCMs. The design of these materials is accompanied by material characterization of cementitious binders. This has been accomplished using techniques that involve measurement of heat evolution (isothermal calorimetry), determination and quantification of reaction products (thermo-gravimetric analysis, x-ray diffraction, micro-indentation, scanning electron microscopy, energy-dispersive x-ray spectroscopy) and evaluation of pore-size distribution (mercury intrusion porosimetry). In addition, macro-scale testing has been carried out to determine compression, flexure and durability response. Numerical simulations have been carried out to understand hydration of cementitious composites, determine optimum particle packing and determine the thermal performance of these composites. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2018

Les impacts de la construction sur l'environnement et sur la santé des habitants sont aujourd'hui des enjeux prioritaires. Les matériaux en terre crue connaissent un essor important pour de nombreuses raisons (écologique, économique, etc.), mais des questions se posent sur leur sensibilité à la prolifération des moisissures vis-à-vis de la qualité de l'air intérieur. Au cours de ces travaux, les flores bactériennes et fongiques présentes sur des supports en terre crue, biosourcés ou non, au sein d'habitations, ainsi que dans les matières premières, ont été caractérisées selon des méthodes par culture et par métabarcoding. Les champignons détectés sont similaires à ceux présents dans les habitations conventionnelles. L'ajout de fibres végétales ne modifie pas la structure des communautés fongiques mais rend le matériau plus sensible à la prolifération. Celle-ci n'intervient qu'en condition d'accident hydrique. Des approches de lutte biologique à partir de bactéries ont été initiées pour inhiber la prolifération fongique sur ces matériaux. / Impacts of building on environment and on health of inhabitants are nowadays priority issues. The interest for earthen materials is increasing for many reasons (ecological, economical, etc.), but some questions are raised about their fungal proliferation sensitivity considering the quality of indoor air. This work consists in characterizing by cultural and metabarcoding methods the fungal and bacterial communities on the surface of earthen building materials, biobased or not, and raw materials. Detected fungi are related to those which are identified in conventional buildings. The addition of vegetal fibers don't modify the fungal communities structure, but make the material more favorable for proliferation. The fungal development appears only under water damage condition. Biocontrol methods with bacteria have been initiated in order to inhibit the fungal proliferation on these materials.