Dissertations / Theses on the topic 'Earth plaster'

In this project I look at our relationship to Nature and how it is expressed in western material culture.  I propose that this relationship is ambivalent and paradoxical and seek means to make this evident.  I look to 18th century gardens for a historical and cultural context and to Rene Descartes for an explanation as to how this ambivalence came to be.  This is the work of someone who thinks too much, makes cynical and wide sweeping assumptions about human behavior and has access to a workshop 7 days a week for 2 years.

My stoneware sculptures in my MFA final project were named Earth Divers because clay as a material is earth and clay is also symbolic of the Earth. The way that I physically dive into clay up to my elbows is a poetic performance. The sculptures were built in sections horizontally and then stacked vertically. I began the process by first making life size plaster molds of the human figure taken from live people. Earth Divers take their architectural structure specifically from the organic curves of the negative voids that are characteristic of the plaster figure molds. I built into these plaster molds a block or brick like section. I then removed the large block sections from the molds and stacked the sections one on top of the other combining the figurative and architectural structures with gothic influence. The sculptor, Stephen De Staebler, who works in a similar fashion, describes his work as, "... first laying the figure down and later standing it in a vertical position." The way of life that was lost with the manufacturing past of my family at Castone Brick is found in the use of industrial nostalgia by modeling I-beam shapes as part of the structure of the stacked sections. I also fired nuts, bolts, and washers of various sizes in the clay that build the surface of the human forms. The square nut seen in my work is no longer being manufactured and is symbolic of the passing of the industrial age in America. Finally, to build the surfaces of my sculptures I used slips, glazes, and a variety of clays on top of clay, and laid glass fragments on the horizontal surfaces to create a look of pooled water when my work was fired similar to what I have seen in the Lehman Caves in Baker, Nevada. "I believe there is a force in this world that lives beneath the surface, something primitive and wild that awakens when you need an extra push just to survive, like wild flowers that bloom after a fire turns the forest black. Most people are afraid of it and keep it buried deep inside themselves. But, there will always be a few people who have the courage to love what is untamed inside us." (Tim McGraw)

The theme of this thesis are surfaces made of unburned earth and used in architecture. The thesis focuses mainly on detailed mapping and analysis of the present state. However, it does not omit the historical roots of earthen surfaces in the area of today`s Czech Republic. In these roots it looks for connections with contemporary practice. The thesis deduces conclusions from thorough evaluation of the present situation – it shows perspectives and possible drift of the future development of earthen surfaces. Both in the field of architecture and in areas broadening this field.

Secteur clé dans la lutte contre le réchauffement climatique et dans la transition énergétique, le domaine du bâtiment doit prioritairement repenser et transformer son activité. L'utilisation de matériaux premiers et biosourcés permet, entre autres, de répondre efficacement à ces enjeux environnementaux. Ils participent à la préservation des ressources naturelles et à la diminution des consommations de matières premières d'origine fossile par valorisation de déchets ou coproduits renouvelables ainsi qu'à la limitation des émissions de gaz à effet de serre et à la création de nouvelles filières économiques. Dans ce contexte, le travail de thèse réalisé vise à proposer une solution constructive bio et géosourcée à faible impact environnemental. Ainsi, un matériau d'isolation thermique répartie en béton végétal, utilisé en remplissage d'une structure porteuse, est considéré ici. Pour la formulation de béton léger, le potentiel de deux agroressources, le maïs et le tournesol, est évalué. Ces granulats disponibles localement sont considérés en remplacement de la chènevotte de chanvre, couramment utilisée mais plus faiblement disponible. Ils sont alors associés à un liant. Deux matrices minérales différentes sont utilisées dans l'étude : une chaux formulée et un liant pouzzolanique. L'exploration de la microstructure des matériaux composites et de leurs composants, ainsi que l'étude des interactions entre les différentes phases permettent une compréhension des performances hygrothermiques et mécaniques des matériaux développés. La plus forte porosité ouverte des composites à base de liant pouzzolanique confère aux agrobétons une capacité tampon hygrique supérieure à celle des matériaux à base de chaux formulée. Par ailleurs, les hydrosolubles de maïs ont un effet délétère sur la prise et le durcissement du liant, compromettant ainsi le comportement mécanique du béton végétal durci qui est alors incompatible avec son utilisation en construction. Au regard des propriétés d'usage, la formulation à base de liant pouzzolanique et de granulats de tournesol apparaît donc comme étant la plus satisfaisante. Rarement laissés à l'état brut dans un bâtiment, ces agrobétons sont recouverts d'un enduit susceptible d'altérer les performances hygrothermiques de la paroi. La deuxième partie du travail de thèse consiste à évaluer et optimiser les performances d'un enduit de finition en terre crue. Dans ce type d'enduit, le rôle de liant est joué par la fraction argileuse contenue dans la terre. Cette propriété colloïdale peut s'accompagner de variations volumiques importantes en fonction de l'état hydrique du matériau et de la nature minéralogique des argiles, pouvant conduire à une fissuration de l'enduit au séchage.[...]
As a key sector in the fight against climate change and in the energy transition, the building industry must re-think and transform its activity. The use of raw and bio-based materials can help to respond to this environmental challenge effectively, enabling natural resources to be saved thanks to the recovery of agricultural waste and by-products, the consumption of fossil raw materials to be reduced, greenhouse gas emissions to be limited, and new economic sectors to be created and developed. In this context, this thesis research project aims to develop a constructive bio- and geo-based solution with low environmental impact. A thermally self-insulating vegetal concrete, used to fill a load-bearing structure, is considered. For the mix design of this lightweight concrete, the potential of two agricultural by-products, maize and sunflower, is evaluated. These two locally available aggregates are considered as substitutes for hemp shiv, which is currently the most commonly used of such products even though little is available. They are then mixed with a binder. Two mineral matrices are considered in the study: a lime-based preformulated binder and a metakaolin-based pozzolanic binder. The exploration of the microstructure of both vegetal concretes and their components, together with studies of the chemical interactions between the lignocellulosic particles and the mineral binder, provide a better understanding of the hygrothermal and mechanical performances of the bio-based materials developed. The very open and interconnected pore structure of pozzolanic-based composites is responsible for their higher moisture buffering capacity than those obtained with lime-based materials, while the water-soluble components of maize disturb the setting time and the mechanical behaviour of mineral binders after hardening, thus preventing the use of maize-based concrete in construction. From the standpoint of suitability for use, pozzolanic binder and sunflower bark chips appear to be the most promising combination of raw materials for designing a hygrothermally and mechanically effective bio-aggregate based concrete. In practice, vegetal concrete walls are rarely left uncoated in a building. The presence of wall coating is likely to influence the hygrothermal behaviour of the wall. The second part of the thesis work consists of evaluating and optimising the performances of an unfired earth-based finish coating. In this type of plaster, the clayey phase ensures the global cohesion of the material by acting as a binder for the sand grain skeleton. Depending on the water state of the material, more or less affected by the soil mineralogical composition, clay can induce drying shrinkage of the mortar, leading to cracking of the plaster. [...]

Le pisé est une technique constructive vernaculaire consistant à compacter successivement des couches de terre humide entre des coffrages. Cette technique, présente dans le monde entier, l'est en particulier en France dans la région Auvergne-Rhône-Alpes. Comme il n'existe pas de réglementation attachée à cette technique constructive, il est très difficile pour des propriétaires de réparer leur bien. Le développement de cette technique pour de nouveaux projets souffre aussi de cette absence alors qu'elle répond à certains enjeux posés par le Développement Durable. Le travail présenté ici fait partie intégrante du projet national PRIMATERRE dédié à l'étude des constructions impliquant de la terre. Une loi de comportement élasto-plastique est développée dans ce travail pour modéliser le comportement du pisé. Elle s'appuie sur une approche hiérarchisée de la modélisation en lien avec le nombre d'essais disponibles pour identifier les paramètres de modèle mais aussi en lien avec la complexité de phénomènes à prendre en compte. Ce modèle s'inspire d'un modèle pré-existant, CJS, développé en géotechnique pour modéliser le comportement mécanique des matériaux granulaires. Une adaptation s'est imposée pour prendre en compte les spécificités du comportement mécanique du pisé qui possède de nombreuses similitudes avec celui des matériaux quasi-fragiles. Deux niveaux de modélisation pour le modèle de comportement appelé CJS-RE sont présentés, pouvant être utilisés dans un contexte de sollicitation monotone. Le premier niveau CJS-RE1 est un modèle élastique parfaitement plastique alors que le second niveau CJS-RE2 est un modèle élasto-plastique à écrouissage isotrope. Deux mécanismes de déformation plastique sont présents, l'un lié aux phénomènes purement déviatoires et l'autre aux phénomènes de traction. La validation du modèle a été entreprise sur la base de la simulation d'essais en laboratoire de compression diagonale et de chargement latéral (pushover) sur des murets, issus de la littérature. Le niveau CJS-RE1 a été capable de capturer les phénomènes essentiels issus de ces deux tests et peut être utilisé comme une première approches des problèmes. Le niveau CJS-RE2 a permis de retrouver plus précisément le comportement non linéaire du pisé sur une large gamme de déformations, que ce soit dans l'essai de compression diagonale ou dans le pushover. Enfin, la prise en compte d'interfaces entre les couches dans la modélisation semble constituer une approche surdimensionnée lorsque seule la résistance d'un système constitué en pisé est recherchée. Cependant, parce qu'elles apportent une certaine ductilité au système dans la modélisation, elles peuvent être utilisées lorsque des résultats plus détaillés sont attendus
Rammed earth is a vernacular building technique consisting in compacting successively layers of moist earth within formworks. This technique is present worldwide and in particular in the region Auvergne-Rhône-Alpes in France. As no regulation exists for rammed earth structures in France, the owners of such structures are helpless at the time when repairing damages appearing in any aging heritage structures. Moreover, this lack of regulation tends to slow down the development of such a constructive solution in new projects though this technique answers many of the issues raised by the sustainable development. The work presented herein is part of the national research project PRIMATERRE devoted to the study of construction building involving earth. Herein, an elasto-plastic constitutive law is developed for modeling the behavior of rammed earth. It is based on a hierarchical approach of the modeling in relation to the information available to identify the set of model parameters and the refinement of phenomena to be modelled. This model was adapted from a pre-existing CJS model used in advanced foundation engineering for the modelling of granular soils. The necessary adaptation of some mechanisms of the model in the context of rammed earth material which holds the characteristics of a quasi-brittle material is highlighted. Two levels for the model denoted CJS-RE which can be used in the context of monotonous loadings are presented herein. The first level is a simple elastic perfectly plastic model (CJS-RE1) and the second model is an elasto-plastic model with an isotropic hardening (CJS-RE2). Two mechanisms of plastic deformation are involved, one related to purely deviatoric phenomena and one related to tensile phenomena. The validation of the model was performed based on different sets of actual tests including diagonal compression tests and pushover tests on wallets. The simple elasto-plastic model CJS-RE1 was able to capture some basic features for these two tests and may be used for a first estimate of the system resistance. The more sophisticated model CJS-RE2 was found better to retrieve the nonlinear behavior of rammed earth over a larger range of deformations throughout both a diagonal compression test and a pushover test. Finally, the modelling of interfaces between layers of earth seems oversized when the resistance of the system is investigated. However, since they may influence the simulated ductility of the system, they may be used to model the behavior of rammed earth system more precisely

This thesis presents the development of a high-resolution viscous-plastic (VP) sea ice model. Because of the fine mesh and the size of the domain, an efficient and parallelizable numerical scheme is desirable. In a first step, we have implemented the nonlinear solver used in existing VP models (referred to as the standard solver). It is based on a linear solver and an outer loop (OL) iteration. For the linear solver, we introduced the preconditioned Generalized Minimum RESidual (pGMRES) method. The preconditioner is a line successive overrelaxation solver (SOR). When compared to the SOR and the line SOR (LSOR) methods, two solvers commonly used in the sea ice modeling community, pGMRES increases the computational efficiency by a factor of 16 and 3 respectively. For pGMRES, the symmetry of the system matrix is not a prerequisite. The Coriolis term and the off-diagonal part of the water drag can then be treated implicitly. Theoretical and simulation results show that this implicit treatment eliminates a numerical instability present with an explicit treatment. During this research, we have also observed that the approximate nonlinear solution converges slowly with the number of OL iterations. Furthermore, simulation results reveal: the existence of multiple solutions and occasional convergence failures of the nonlinear solver. For a time step comparable to the forcing time scale, a few OL iterations lead to errors in the velocity field that are of the same order of magnitude as the mean drift. The slow convergence is an issue at all spatial resolutions but is more severe as the grid is refined. It is attributed in part to the standard VP formulation that leads to a momentum equation that is not continuously differentiable. To obtain a smooth formulation, we replaced the standard viscous coefficient expression with capping by a hyperbolic tangent function. This provides a unique solution and reduces the com
Cette thése de doctorat présente le développement d'un modéle a haute résolution visco-plastique (VP) de la glace de mer. Etant donné le maillage fin utilisé et la taille du domaine, un schéma numérique efficace et parallélisable est souhaitable. En premier lieu, nous avons utilisé le solveur non linéaire utilisé dans les mod éles VP existants (appelé le solveur standard). Ce solveur non linéaire est basé sur un solveur linéaire et une boucle externe (BE). Comme solveur linéaire, nous avons appliqué la méthode du résidu minimal généralisé avec préconditionneur (pGMRES). Le préconditionneur est un solveur de surrelaxation successive (SOR) par ligne. En comparant avec les autres méthodes utilisées dans la communauté, nous avons constaté que pGMRES est 16 fois plus rapide qu'un solveur SOR et 3 fois plus rapide qu'un solveur SOR par ligne. Pour pGMRES, la symétrie de la matrice du systéme n'est pas requise. Le terme de Coriolis et la partie hors diagonale de la contrainte du vent peuvent donc etre traités implicitement. Des résultats théoriques et des simulations démontrent que ce traitement implicite élimine une instabilité qui peut etre présente dans le cas d'un traitement explicite. Au cours de cette recherche, nous avons aussi observé que la solution non linéaire approximée converge trés lentement avec le nombre d'itérations de la BE. De plus, des résultats de simulation montrent: l'existence de solutions multiples et des cas de non convergence du solveur non linéaire. Lorsque le pas de temps est comparable a l'échelle temporelle du forçage, un petit nombre d'itérations de la BE implique des erreurs sur les vitesses simulées du meme ordre de grandeur que la vitesse moyenne. La lente convergence est un probléme pour toutes les résolutions spatiales mais est plus sévére a haute résolution. Elle est attribuable entre autr

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991.
Vita.
Includes bibliographical references.
by Joanne Theresa Fredrich.
Ph.D.

Excessive settlement and foundation instability are some of the main problems commonly encountered in fills and embankment structures built on a soft soil of low bearing capacity.The Expanded Polystyrene(EPS)replacement method, by partially or fully replacing the conventional fill material with extremely lightweight EPS geofoam, may solve these problems. In this thesis, experimental and theoretical work have been carried out to investigate the behaviour of EPS under various loading conditions in geotechnical applications and the effectiveness of EPS replacement technique has been studied using numerical models.Several tests were performed for this study and the results of these tests are given
Doctor of Philosophy (PhD)

Thesis (Ph.D.) -- University of Western Sydney, Nepean, 2001.
A thesis submitted for the degree of Doctor of Philosophy, School of Civic Engineering and Environment, University of Western Sydney, Nepean, January, 2001. Bibliography : p. 215-225.

Les travaux s'inscrivent dans le cadre de la protection contre la propagation d'incendie. On distingue les protections actives,regroupant l'ensemble des actions allant de la détection d'un incendie à l'intervention des secours, des protections passivesparties intégrantes de la structure des bâtiments. Ces protections peuvent être appliquées directement sur les structures à protéger par projection, ou venir les recouvrir au moyen de panneaux plus ou moins épais assemblés. L'assemblage de panneaux permet également de former des conduits de ventilation ou de désenfumage. Les travaux entrepris portent sur la caractérisation du comportement de matériaux minéraux dédiés à la construction sous chargement thermique sévère. Le cas de liants hydratés homogènes fortement perméables est particulièrement étudié et les matériaux à base de sulfate de calcium en est l'illustration. En effet, la faible conductivité thermique et la capacité de chaleur latente du plâtre représentent des critères importantspour limiter dans le temps les transferts thermiques. Cependant, son utilisation est limitée par ses faibles propriétésmécaniques. Afin d'identifier et de comprendre les différents mécanismes entrant en jeu lors d'une élévation de température de type incendie, une caractérisation multi-échelle a été développée sur des matériaux à base de gypse. Les travaux sont réalisés avec un plâtre pris fabriqué à partir d'un hémihydrate β naturel gâché à l'eau. A la micro-échelle, la composition du produit de base et ses propriétés thermiques ont été étudiées. Une attention particulière a été portée à lidentification des cinétiques de changements de phases. A la méso-échelle, une caractérisation mécanique et structurale est réalisée à température ambiante. Des essais thermogravimétriques sont également développés : (i) sur des échantillons cylindriques en condition isotherme, ce qui permet d'y associer une analyse dilatométrique et une caractérisation après refroidissement des résistances mécaniques et de la porosité ; (ii) sur des échantillons sphériques, à rampe de chauffe imposée, pour étudier les cinétiques de transferts pour une chauffe isotrope. Le rôle de la micro-échelle est mis en avant pour chaque configuration.A la macro-échelle, nous travaillons avec des panneaux plans dont une des faces est sollicitée thermiquement par élévationde température normalisée : ISO 834. La configuration d'étudeest horizontale. Une caractérisation du comportementthermique, hydrique, chimique, structurale et mécanique est alors mise en oeuvre. L'analyse du comportement espacetempspermet de distinguer l'influence de la température dansl'avancement de la déshydratation mais également le rôle desvitesses de chauffe et de la micro-échelle. Ces travaux se terminent par la caractérisation multi-échelle de mélanges plâtre-fumée de silice. Ces formulations permettent notamment d'améliorer la tenue du matériau à haute température et ainsi de prolonger la durée de protection

A linear economy, which usually describes the current economic model, has not considered the ecological and social perspectives. This can be explained by increased consumption patterns, especially in the western world, led to large amounts of waste, reduced limited natural resources and increased environmental problems. Circular economy has been presented as a sustainable economic model where resources are reused as far as possible and the production of goods is to be made without toxic substances and with renewable energy instead of fossil fuels. This thesis aims to examine what defines a circular business model and how companies' business models differ within linear and circular economic models from a perspective of sustainable development. It also examines possible problems that exist in the development of circular business models. Plastic is a case in point used in this thesis, as the material is well used within the linear economy and leads to increasing environmental issues. The theoretical framework the examination was based on has its origins in the business economics literature on business models. From this literature, an ideal circular business model was designed to be able to compile the results and compare business models within the companies. This thesis indicates a lack of perspicuity in what the circular business model looks like. With the help of ten desk studies and one semi-structured interview the difference between circular and linear business models in perspective of sustainable development has proven to be rather unclear. However, it was possible to show that the majority of the studied circular companies use more environmentally friendly materials and showcase more partnerships in regards to increasing social work. The study also identifies a certain problem within the creation of a circular business model as the meaning includes a lack of definition. This can validate companies that advocate the environment and consider themselves as circular when, according to the study´s ideal business model, they do not meet all criteria.
En linjär ekonomi, som vanligtvis beskriver den nuvarande ekonomiska modellen, har inte tagit hänsyn till ekologiska och sociala perspektiv. Detta kan förklaras av ökade konsumtionsmönster, särskilt i västvärlden, som lett till stora mängder avfall, minskade ändliga naturresurser och ökade miljöproblem. Cirkulär ekonomi har presenterats som en hållbar ekonomisk modell där resurser återanvänds så långt det går och produktionen av varor ska göras utan toxiska ämnen och med förnybar energi istället för fossil. Denna uppsats syftar till att undersöka hur den cirkulära affärsmodellen ser ut och hur företags affärsmodeller skiljer sig inom de linjära och cirkulära ekonomiska modellerna utifrån perspektivet hållbar utveckling. Vidare undersöks eventuella problem i utvecklandet av cirkulära affärsmodeller. Plast är ett typexempel i uppsatsen eftersom materialet används mycket inom den linjära ekonomin och leder till ökade miljöproblem. Den teoretiska ram som undersökningen baseras på har sitt ursprung i företagsekonomisk litteratur om affärsmodeller. Ur denna litteratur har en ideal cirkulär affärsmodell konstruerats för att sammanställa resultatet och jämföra företagens affärsmodeller. Studien visar att det inte finns en tydlighet i hur den cirkulära affärsmodellen ser ut. Med hjälp av tio skrivbordsstudier och en semistrukturerad intervju har skillnaden mellan cirkulära och linjära affärsmodeller i perspektivet av hållbar utveckling visats vara relativt diffus. Dock visar uppsatsens resultat att majoriteten av de undersökta cirkulära företagen använder mer miljövänliga material och har fler partnerskap rörande ett utökat socialt arbete. Studien identifierar även att det finns en viss problematik i utformningen av cirkulära affärsmodeller då innebörden innefattar definitionsbrister. Detta kan validera företag som förespråkar miljö och anses som cirkulära när de enligt studiens ideala affärsmodell inte uppfyller alla kriterier.

Cirka 35 tusen ton plast beräknas flyta omkring i haven. Där plastkoncentrationerna ärsom störst antas det bero på havsströmmar, nedskräpning från folktäta kuster menäven fiskeredskap som lämnats kvar eller gått sönder till havs. På grund av UVstrålning,saltvatten och kemiska reaktioner vittrar plastpartiklarna sönder och bildardet som kallas för mikroplast. Avsiktligt tillverkade mikroplaster kan även tillsättastill produkter med olika önskvärda egenskaper, exempelvis som en polerande effekt itandkräm och andra hygienartiklar. De plastpolymerer som återfinns mest i haven ärpolyetylen (PE), polypropylen (PP), polystyren (PS) och polyetylen tereftalat (PET).Man har hittat mikroplaster i olika marina livsmedel såsom som räkor, musslor samtolika matfiskar bland annat torsk men även i livsmedel som havssalt. Det är docksvårt att säga hur dessa mikroplaster kan påverka vår hälsa men konsumerar man fiskoch skaldjur finns det en risk att man också konsumerar mikroplaster. Trots attmikroplaster upp till 5 millimeter med största sannolikhet passerar vårtmatsmältningssystem vid konsumtion, finns det ändå risker då tillsatser iplastpolymererna kan vara hormonstörande och cancerogena.

In the context of the critical sustainability problem of marine plastic pollution, the present paper presents a quasiexperimental research that explores the effects that participating on beach clean-up has on students’ knowledge,awareness and behavioural intentions. Considering this intervention as an outside of school practical implementation of Education for Sustainable Development (ESD), this research aims to determine if the addition of direct experiences with nature within ESD programs can lead to a behavioural change in favour of the environment. Analysing the factors that influence pro-environmental behaviour and the role that ESD has on transforming society towards a more sustainable one, a one-time pre-test post-test research with non-equivalent groups was performed. A questionnaire on beach litter and self-reported behaviour, implemented in two schools of the Amalfi Coast, Italy, indicate that in comparison to a group which only received a lecture, a group that participated in a beach clean-up increased their knowledge and awareness towards marine plastic pollution, in addition to their willingness to participate in another beach clean-up. This supports the theory that learning in nature can have a higher influence in shaping pro-environmental behaviour, and therefore the inclusion of this type of activities within ESD programs can help beat marine plastic pollution.

Syftet med denna kvalitativa studie är att genom fokusgruppintervjuer undersöka vad elever i årskurserna 5-6 kan och  resonerar om begreppen källsortering, nedskräpning och miljöförstöring Studien tar upp hur hållbar utveckling är upplagt i läroplanens inledande delar och kursplaner, hur de tre dimensionerna av hållbarhet definieras samt tidigare forskning inom ämnet. I det resultat som visualiseras framkom det hur 20 elever på en Grön Flaggskola och en icke Grön Flaggskola ser på nedskräpning och källsortering. Undersökningens resultat indikerar att eleverna är väl insatta i dagens miljöproblem och de vet hur de ska motverka dessa. Anmärkningsvärt visade eleverna på Grön Flaggskolan inte mer kunskap om till exempel hållbarhet. Dock påvisas det att majoriteten av eleverna på båda skolorna innehar en nonchalant inställning till problemen, lägger dessa på andra individer och skjuter problemen framför sig. I studien framförs slutligen en diskussion om införandet av ett nytt ämne i läroplanen, vem som bär ansvaret och hur lärarna kan engagera sina elever att arbeta för en bättre planet.
The purpose of this qualitative study is, through focus group interviews investigate what pupils in grades 5-6 can and reason about waste sorting, littering and pollutions. The study examines how sustainable development is presented in the curriculum's introductory parts and curricula, how the three dimensions of sustainability are defined and previous research within the subject. The result that emerged visualizes how 20 pupils at an Eco-School and a non-Eco-school look at littering and sorting waste. The results of the survey indicate that the pupils are well acquainted with today's environmental problems, and they know how to counteract with these. The pupils on the Eco School did remarkably not show more knowledge about for example sustainability. However, it is demonstrated that the majority of the pupils at both schools hold a nonchalant approach to the problems, place these on other individuals and postpone the problems before them. Finally, the study discusses the introduction of a new topic in the curriculum, who carries the responsibility and how the teachers can engage their students to work for a better planet.

Cette étude a pour objet de comparer les propriétés acoustiques, mécaniques et hygrothermiques de différents biocomposites destinée à l’isolation des bâtiments à base de granulats issus de co-produits végétaux et d’un liant à base d’argile. Nous avons d’abord analysé les matières premières afin d’obtenir d’une part la masse volumique et les propriétés thermiques et hydriques des granulats végétaux et les caractéristiques minéralogiques et gravimétriques de la terre crue sélectionnée d’autre part. L’évolution de la conductivité thermique des mélanges terre:granulats végétaux a été étudiée à différents taux d’humidité et différentes masses volumiques. D’un point de vue hydrique, les capacités de sorption/désorption de ces matériaux ont été mesurées en régime statique de même que la capacité de tampon hydrique simulant un régime dynamique. L’un des principaux intérêts de cette étude est de confirmer qu’une large gamme de co-produits végétaux produits à l’échelle locale pourrait être utilisée en tant que granulats pour l’élaboration de bétons végétaux
The purpose of this study was to compare hygrothermal acoustical and mechanical properties ot different materials based on vegetal aggregates and clay in order to characterize the performances of different biocomposites to provide building insulation solutions with a view to valorizing agricultural waste. We first analyzed the raw materials in order to get the density, thermal and hydric properties of the vegetal aggregates in one hand and the mineralogy and gravimetric data of the selected crude earth in the other hand. Thermal behavior of earth:vegetal aggregates mixes have been investigated at different humidity rates and different density ranges. Additionally, hydric properties have been measured to produce sorption and desorption curves and moisture buffer values (MBV) in one hand and capillarity of both aggregates and biocomposites on the other hand. One of the main interests of this study is to confirm that a wide range of locally produced vegetal byproducts could be used as - bioaggregates for concretes. Local biomaterials industries could therefore emerge depending on the locally available resources at country scale

Globally, there is a need for alternative building materials that require less energy to produce than conventional materials. These alternative materials have gained popularity in recent years, however there is a need to better understand their physical properties in order to increase confidence in their use. As such, a testing program was undertaken to investigate the structural properties of some of these materials. A series of compressed earth blocks made from a mixture of earth and cement compressed to 8 - 12 MPa were tested for their compressive capacity in masonry prisms. The blocks had been weathered for one to two years. The blocks with no cement had a capacity of 2.22 MPa, while cement stabilized blocks had a capacity of 8.11 MPa. Weathering did not result in any significant reduction in the strength of the blocks. Bales of high density straw were tested both with and without cement plaster skins. Unplastered bales exhibited a stiffness between 0.3 - 0.7 MPa when oriented Flat, and 1.2 MPa on edge. The bales had a dilation ratio between 0.1 - 0.3 in the Flat orientation and averaging 3.5 in the Edge orientation. The high density bales plastered with cement plaster exhibited ultimate strengths averaging 171.2 kN/m. Capacity was heavily dependent on plaster strengths, and when normalized for plaster strengths, high density bales had capacities lower than those of regular density bales tested previously (34.1 kN/m/MPa compared to 44.3 kN/m/MPa). Three walls made of straw with cement plaster were constructed with pin-ended conditions to study the effects of buckling in straw bale walls. The average capacity was 12.8 kN/m/MPa when normalized for plaster strength. Pin ends resulted in plastic hinges forming more easily in the walls, and pin ended specimens had a 75% reduction in strength compared to previous tests of "standard" end conditions. Taller walls also resulted in reduced strengths.
Thesis (Master, Civil Engineering) -- Queen's University, 2013-10-30 09:26:46.491

Bioconsolidation is a relatively novel technique used for consolidation, repair, protection and improvement of construction materials. This biotechnology is based on the precipitation of chemical compounds produced by microbial metabolism. It can be used for treatment or formulation. Although recently applied in several construction materials, such as earth blocks or cement-based materials, bioconsolidation has been unexplored on earth-based plastering mortars. Although the use of earth mortars for earth plasters has been growing on recent years for its eco-efficiency, they are less resistant to damage by contact with water. Therefore, the use of a bioproduct may have a great potential for the improvement of earth mortars´ weaknesses. In the present thesis, two types of bioconsolidation techniques have been studied on earth mortars: as a biotreatment for the improvement of surface properties; and as a component for earth mortars’ formulation (bioformulation) for the improvement of the whole material. The bioproducts used are based on microbial iron mineralization using Escherichia coli cells, since iron compounds are present in earth materials, are non-toxic, easy to handle and are not expensive. Several experimental conditions have been studied leading to the proposal that iron concentration is a key parameter. Tested biotreatments show promising results, producing a slight consolidative effect and significant increasing of water absorption resistance of earth mortars. Bioformulated mortars present a very distinct macrostructure, with a great decrease on mechanical properties. Nevertheless, they achieve a considerable improvement on resistance towards water and a lower thermal conductivity. The results show the interest on further studies on the use of iron-based bioproducts on earth mortars.

There has been a rising interest by the building sector in using passive solutions to regulate the indoor relative humidity, since humidity levels can directly affect the health and comfort of the occupants. Earth based materials are known for their ability to regulate the relative humidity and improve indoor comfort. Another motivation is the potential to reduce the energy consumption of air conditioning systems. The assessment of the hygrothermal transfers within earthen walls/plasters has been the focus of many researchers, but the proper modelling and coupling of these characteristics for unconventional materials like earthen walls and plasters still is a major scientific and technical challenge. The main objective of this dissertation consists in first to check the validity of steady state material characteristics obtained through standard procedures. Furthermore, validate different assumptions and the reliability of the different methods to determine the precision of the experimental test results. The second objective is to analyse the influence of temperature on those characteristics and their consequences on the hygrothermal behaviour. For that purpose, two types of porous hygroscopic materials are studied: compressed earth samples and earth plasters with the addition of organic natural fibres. Results showed a high variability due to experimental set ups and conditions. However the influence of temperature on the sorption and transfer properties could be determined. An analysis of the results based on thermodynamics gave surface characteristics and the heat involved in the adsorption and condensation process of the materials used.

Relative humidity influence strongly the indoor air quality and human comfort. Therefore, the hygrothermal behaviour of building materials is an important parameter and there has been a growing interest in studying passive solutions to regulate the indoor relative humidity. Since earth materials have the ability to absorb and release water vapour, they can be used to moderate the amplitude of indoor relative humidity and therefore to improve the indoor air quality and consequently save energy. Many researchers have been focussed on studying the hygrothermal properties of earth building materials, but it is still a scientific challenge to characterize precisely the hygrothermal coupling of those materials. This dissertation focuses on two main objectives, developed and studied in three different porous materials: compacted earth, earth plaster and hemp concrete. The first one is to analyse the effectiveness and the influence of three different drying-methods (oven-drying at 60°C, oven-drying at 105°C and vacuum-drying), and recommend one standard method, for each material studied, since there is no clear guidance to determine the correct dry mass of biobased and earth materials. Complementary to the first objective, it is evaluated the impact of drying/wetting cycles using the same three drying-methods. The second objective is to study the evolution of sorption curves with temperature, for biobased and raw-earth materials. The analysis of the results showed that the first drying process affects the moisture uptake of all the studied materials, from there forward. Oven-drying at 60ºC and vacuum-drying are the methods that produce less impact in the porous network. More specifically, vacuum-drying is the method that allows less impact in the first drying of compacted earth and hemp concrete, and both, vacuum-drying and oven-drying at 60°C, are suitable for a non-impact drying of earth plaster. However, they are not completely efficient in drying earth materials since hysteresis is observed in drying/wetting cycles. Using oven-drying at 105°C it is not observed hysteresis and therefore, this is the most effective method, but it is the method that most presents impact in the porous network after the first drying. Analysing the influence of temperature on the absorption curves, the results show that temperature cycles have no relevant impact on the hygrothermal behaviour of earth materials. Comparing the sorption curves of the three materials plotted at the same temperature, the influence of temperature is more relevant than the materials itself for compacted earth and earth plaster. The same cannot be stated for the hemp concrete.

碩士
國立成功大學
土木工程學系
88
Abstract Finite element software ABAQUS is used to analyse the stress-strain state , and pull-out forces of spread earth anchor .In addition to the pocket commonly used in earth anchor , reinforced-spread earth anchor is proposed with claws sticked to the pocket .These claws are designed to ejected into the soil when high-pressure concrete is filled into the pocket . Mohr-Coulomb failure criterion is assumed to follow the soil failure behavior .The pull-out force and the failure angle of the commonly earth anchor and that of the proposed reinforced-spread earth anchor with claws are analysed .Anchor diameter、anchor depth were both considered as the variables in the analysis. The results show that : 1.The anchor diameter is one of the most import factors to affect the pull-out force . The disturbed soil increased due to the existing of clawed anchor being much greater than that of the common ones when both have the same anchor diameters . 2.The increase of disturbed soil volume depends on the location of the claws as the applied pull-out force is small . As the applied pull-out force increased to the critical pull-out force , the failure angle and the influenced volume of the disturbed soil is closed to that for a common spread earth anchor .

Earth mortar plasters and hemp concrete are hygroscopic materials since they have the ability to uptake and release water vapour. These materials can be used for a passive control of relative humidity (RH) inside buildings, with the benefits of improving the health and comfort of the occupants, as well as reducing the energy consumption of buildings. The quantification of this passive control potential for buildings material has been extensively studied by the scientific community since the last decade. These studies notably lead to the Nordtest project (Rode et al. 2005) where the concept of Moisture Buffering Value (MBV) was developed, as well as a test protocol in order to quantify this characteristic of the material. The main objective of this dissertation is to study the impact of temperature and thickness of a coating material on its passive regulation potential of indoor air RH. For that purpose, two types of hygroscopic coatings materials are studied: earth mortar plasters and hemp concretes. The influence of the thickness is analysed through dynamic MBV test (“Moisture Buffering Value“ test) at 23°C on three formulations of each material (earth and hemp concrete) at three different thicknesses. The influence of temperature is performed only for hemp concrete formulations on static (sorption curves) and dynamic (MBV tests) tests at 23°C and 40°C. The analysis of the results, made using the support of theoretical models, allows underlining that the thickness involved in the daily passive control of RH remains most of the time limited (only the first centimetre of the earth plasters and 5cm for hemp concretes). However, some surface irregularities may have a strong impact on this active thickness. The other main result of this dissertation is the strong impact of temperature on both static and dynamic hygroscopic characteristics of the material. Indeed, the increase of temperature at a constant RH tends to significantly reduce the water content of the material. But, on the other side, due to higher vapour pressure at saturation and water vapour diffusion coefficient, the dynamic sorption-desorption properties increased with temperature by approximately 65%.
Developed within the IBIS project and BIOTERRA project with the collaboration of the "Direction Territoriale Centre-Est" of the CEREMA

Clay plays an important role in the suitability of soil for use in construction. The affinity of a clay for moisture makes it susceptible to shrinkage and swelling on drying and wetting and therefore problematic in terms of construction, where stability is required for the integrity of a structure to remain intact. It is therefore important to have methods of dealing with problematic clays in order to allow clays to be used as a construction material. One of the methods is known as soil stabilisation, where the properties of a soil and mainly the clay fraction are altered to make it more suitable for its intended purpose. The thesis investigates the use of a highly plastic clayey soil for the production of building blocks. Due to the clayey nature and its associated properties the soil it is not suitable in its natural state. Soil stabilisation is investigated as a method to alter the properties of the soil. The principles of soil stabilisation are presented as an introduction to the laboratory testing programme. Combinations of lime, cement and fly ash are investigated as a stabilising agent. They are investigated to determine which combination alters the properties of the soil to such an extent, that a compressed soil block produced using the combination and the clayey soil, would perform satisfactorily according to accepted standards. Combinations were designed so that comparisons could be made between blocks to determine what effect the addition of a certain stabilising agent would have on the performance of the block in terms of the tests conducted. The engineering properties of the untreated soil which are not considered suitable for use in compressed soil blocks, are significantly enhanced by he addition of the stabilising agents. The test conducted on the blocks indicate that the addition of 4% lime, 20% fly ash and 7% cement added to the soil produces a block that satisfies the criteria adopted for the research and that are generally in accord with international standards. A mineralogical analysis was also undertaken in an attempt to identify changes in the mineralogy of the soil, and particularly the clay, as a result of the addition of the three stabilising agents. This analysis was done using x-ray diffraction. Due to the nature of the clay mineral and possibly the poor crystal structure thereof, the results were disappointing. No significant change in the clay was observed to correlate with the results of the improved performance as indicated by the physical tests.