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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Predicting the resistance of fired clay bricks to salt attack

Burgess-Dean, Leon Sylvester, leon.burgessdean@deakin.edu.au January 2001 (has links)
The salt attack of Fired Clay Bricks (FCBs) causes surface damage that is aesthetically displeasing and eventually leads to structural damage. Methods for determining the resistances of FCBs to salt weathering have mainly tried to simulate the process by using accelerating aging tests. Most research in this area has concentrated on the types of salt that can cause damage and the damage that occurs during accelerated aging tests. This approach has lead to the use of accelerated aging tests as standard methods for determining resistance. Recently, it has been acknowledged that are not the most reliable way to determine salt attack resistance for all FCBs in all environments. Few researchers have examined FCBs with the aim of determining which material and mechanical properties make a FCB resistant to salt attack. The aim of this study was to identify the properties that were significant to the resistance of FCBs to salt attack. In doing so, this study aids in the development of a better test method to assess the resistance of FCBs to salt attack. The current Australian Standard accelerated aging test was used to measure the resistance of eight FCBs to salt attack using sodium sulfate and sodium chloride. The results of these tests were compared to the water absorption properties and the total porosity of FCBs. An empirical relationship was developed between the twenty-four-hour water absorption value and the number of cycles to failure from sodium sulfate tests. The volume of sodium chloride solution was found to be proportional to the total porosity of FCBs in this study. A phenomenological discussion of results led to a new mechanism being presented to explain the derivation of stress during salt crystallisation of anhydrous and hydratable salts. The mechanical properties of FCBs were measured using compression tests. FCBs were analysed as cellular materials to find that the elastic modules of FCBs was equivalent for extruded FCBs that had been fired a similar temperatures and time. Two samples were found to have significantly different elastic moduli of the solid microstructure. One of these samples was a pressed brick that was stiffer due to the extra bond that is obtained during sintering a closely packed structure. The other sample was an extruded brick that had more firing temperature and time compared with the other samples in this study. A non-destructive method was used to measure the indentation hardness and indentation stress-strain properties of FCBs. The indentation hardness of FCBs was found to be proportional to the uniaxial compression strength. In addition, the indentation hardness had a better linear correlation to the total porosity of FCBs except for those samples that had different elastic moduli of the solid microstructure. Fractography of exfoliated particles during salt cycle tests and compression tests showed there was a similar pattern of fracture during each failure. The results indicate there were inherent properties of a FCB that determines the size and shape of fractured particles during salt attack. The microstructural variables that determined the fracture properties of FCBs were shown to be important variables to include in future models that attempt to estimate the resistance of FCBs to salt attack.
2

Recyclage des déchets de terre cuite / Recycling of fired clay waste

Cilli-Dogru, Elmas 30 November 2016 (has links)
Le recyclage ou la réutilisation des déchets de démolition de maisons individuelles, de petits collectifs et de sites industriels édifiés en terre cuite, est actuellement limité par la présence de déchets composites, formés par l’assemblage de terre cuite, de mortier et / ou de plâtre principalement. Dans l’optique de valoriser la terre cuite dans la même filière ou dans d’autres secteurs industriels, la présence de plâtre, pouvant générer des ions sulfates au contact de l’eau, est un obstacle. La principal option de fin de vie des déchets de terre cuite en mélange est ainsi l’enfouissement en installation de stockage de classe 3. Le but de cette thèse a été de développer une méthode de séparation des déchets de démolition de terre cuite, plus intéressante d’un point de vue environnemental que l’enfouissement, et permettant de récupérer des matières premières secondaires de terre cuite valorisables dans des filières pertinentes. Une étude du gisement a été réalisée afin d’établir la nature des assemblages en présence dans les déchets de déconstruction et de fournir des échantillons représentatifs. Ces échantillons ont permis la détermination des mécanismes d’adhésion des interfaces. Une méthode de séparation a ainsi été développée et la compatibilité des matières premières secondaires de terre cuite a été comparée vis-à-vis de trois filières de valorisation. / Recycling or reuse of demolition waste from individual houses, small collectives and industrial sites built with fired clay bricks, is currently limited by the presence of mixed waste, which is mainly an assembly of fired clay bricks, mortar and gypsum. In the perspective to valorize fired clay waste from demolition, the presence of gypsum, which may contain sulfates, is a restriction. Currently, the main end-of-life option for non-dissociated fired clay waste is the landfilling in waste storage facilities of class 3. The aim of this PhD thesis is to develop a separation process of mixed fired clay waste, environmentally more friendly than landfilling, in order to recover and valorize secondary raw materials in relevant industrial sectors. A study of the deposit has been done to identify the nature of the mixed demolition waste and to supply representative waste samples. Those samples enable to define the adhesion mechanisms at the interfaces. Then, a separation method has been developed. Finally, three routes have been investigated in order to valorize the recovered clay bricks.
3

Utilization of reclaimed bricks to facilitate circular economy (CE) in the construction industry : A study of Pakistan’s construction industry

Atiq, Adil January 2023 (has links)
This thesis investigates the possible utilization of reclaimed bricks within the framework of circular economy (CE) and sustainable construction approaches, with a particular emphasis on Pakistan's construction industry. The research is based on the theoretical foundations of the Triple Bottom Line (TBL) and Resource Efficiency concepts. Qualitative methods were used to collect data, and a thematic framework was employed to analyse the results. The findings indicate that Pakistan's reclaimed brick sector aligns with the principles of the TBL theory, supporting sustainability in its social, economic, and environmental aspects. Through waste reduction, material reuse, and resource conservation, the industry demonstrates its commitment to environmental preservation. Furthermore, it plays a significant role in the economy by providing affordable infrastructure solutions and contributing to the growth of the construction industry. Additionally, the industry promotes social well-being by providing employment opportunities and financial stability. The study illustrates how Pakistan's reclaimed brick operations effectively integrate social, economic, and environmental factors to create a more environmentally friendly built environment. In summary, reclaimed bricks present a sustainable and resource-efficient alternative for the construction industry, in line with the principles of resource efficiency, preserving resources, minimizing waste, and promoting circular economy practices. The adoption of reclaimed bricks can help Pakistan and other countries achieve their sustainability objectives, reduce environmental impact, and construct structures that are longer-lasting and resource-efficient.
4

Homogenization of mechanical and thermal properties of fired clay bricks : effects of porosity / Homogénisation des propriétés mécaniques et thermiques des briques d'argile cuites : effet de la porosité

Tian, Zeye 28 June 2018 (has links)
En raison de l'exigence de protection de l'environnement, les briques d'argile cuites sont face à une nouvelle tendance de développement. Briques d'argile cuites ne sont pas seulement satisfaits de la mécanique force mais aussi augmentation de l'utilisation de l'énergie. La conductivité thermique est un paramètre très important mesurer l'utilisation de l'énergie. Sur le principe de garantir essentiellement propriétés mécaniques, la réduction de la conductivité thermique a été l'un des développements importants objectifs dans l'industrie du bâtiment.Basé sur l'analyse de la microstructure, les pores microscopiques ont un effet sur la macroscopie constantes élastiques et conductivité thermique. Micropores parallèles résultant de la production les méthodes provoquent l'isotropie transversale des briques d'argile cuites. Cependant, ce n'est pas clair que l'influence des micropores sur les propriétés macroscopiques. Bien que certains modèles étudié l'effet de la porosité sur les propriétés mécaniques des briques d'argile cuite, ces modèles sont empiriques et ont ignoré de nombreuses informations microscopiques. Un des buts de la thèse est d'analyser l'influence de la forme, l'orientation et la distribution spatiale de microscopique facteurs sur les propriétés mécaniques et la conductivité thermique afin de fournir une référence optimiser la micro-structure des briques d'argile cuites. / Due to the environmental protection requirement, fired clay bricks are facing new development tendency. Fired clay bricks are not only satisfied with mechanical strength but also rising energy utilization. Thermal conductivity is a very important parameter to measure the energy utilization. On the premise of guaranteeing the basically mechanical properties, reducing thermal conductivity has been one of important development goals in building industry.Based on the analysis of micro-structure, microscopic pores have an effect on macroscopic elastic constants and thermal conductivity. Parallel micropores resulting from producing methods cause the transverse isotropy of fired clay bricks. However, it is not clear that the influence of micropores on the macroscopic properties. Though some models studied the effect of porosity on mechanical properties of fired clay bricks, these models are empirical and ignored many microscopic information. One of the goals of the thesis is to analyze the influence of shape, orientation and spatial distribution of microscopic factors on mechanical properties and thermal conductivity in order to provide a reference to optimize the micro-structure of fired clay bricks.
5

Propriedades de argamassas obtidas pela substituição parcial de cimento Portland por rejeitos particulados de tijolos / Mortars Properties Obtained by Partial Replacement of Portland Cement by Ground Waste Calcined Clay Bricks

Scandolara, Juliano Pedro 29 July 2010 (has links)
Made available in DSpace on 2016-12-08T17:19:36Z (GMT). No. of bitstreams: 1 PRE-TEXTUAIS.pdf: 48578 bytes, checksum: 21f78cab7ee8f139f12bf814c8bfa87f (MD5) Previous issue date: 2010-07-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work describes the results of an investigation on the possible applications of ground waste calcined clay bricks (WCB) for use as an active partial replacement for Portland cement in mortars. The investigation has been carried out using a full factorial design for experimental design. For the study, the physical and mechanical properties along their durability of mortar produced with WCB were investigated and the results presented. Mortar mixtures were prepared using WCB as the partial replacement of Portland cement at the level 10%, 20% and 30 wt.% with water/cement ratios of 0.45, 0.55 and 0.65. The necessary data for establishing a mix proportion design and a quality control method are obtained. Properties of fresh (consistency index and specific gravity) and hardened (7-day, 28-day and 120-day compressive strength, 28-day water absorption and 28-day alkali content) mortars were evaluated on specimens. Such statistical modeling is discussed against qualitative X-ray diffraction and microstructures of some selected samples were studied using SEM. Several empirical equations, surface and contour plots for the physicalmechanical properties of fresh and hardened recycled mortar with WCB as replacement content were obtained via regression analysis. The influence of level of WCB on the properties has been established, and its suitability for use in a mortar application has been assessed. The consistency decreased in parallel to an increase in the proportion of WCB. Specific gravity of mortars was far lower than that of normal no replacement mortars. A given 28-day compressive strength (21 MPa to 37 MPa) can be achieved at several water/cement ratio and the replacement contents up to 30 wt. %, thus producing na economical mixture mortar with WCB and lower cement Portland content. XRD and SEM analyses results indicated the presence of quartz, calcite, ettringite, portlandite, and silicates in recycled mortars. / Este trabalho apresenta os resultados da investigação do uso de rejeitos particulados de tijolos (RPT) na forma de pó, proveniente de tijolos de cerâmica vermelha, como substituinte parcial do cimento Portland, na produção de argamassas para construção civil. O estudo foi realizado adotando-se o projeto fatorial completo 32 acoplado com técnicas de metodologia de superfícies de resposta. Foram preparadas argamassas usando RPT em níveis de 10%, 20% e 30% (em massa), em substituição ao cimento Portland, com os níveis de relação água/cimento de 0,45, de 0,55 e 0,65. As misturas foram curadas por períodos de 7, 28 e 120 dias. As propriedades das argamassas contendo RPT no estado fresco foram avaliadas: massa específica e índice de consistência. As propriedades avaliadas das argamassas com RPT no estado endurecido foram: resistência à compressão (7, 28 e 120 dias), absorção de água aos 28 dias e teor de álcalis (CaCO3) aos 28 dias. Os resultados obtidos através da metodologia estatística foram confrontados com as análises de difração de raios X (DRX) e microscopia eletrônica de varredura (MEV) de amostras selecionadas. Foram obtidas equações empíricas, gráficos de superfície de resposta e de contorno para as propriedades físico-mecânicas das argamassas com RPT no estado fresco e endurecido, por meio de análise de regressão. A consistência diminuiu linearmente com o aumento da quantidade de RPT incorporado em substituição ao cimento Portland. A massa específica das argamassas contendo RPT foi menor do que na argamassa sem RPT. Foi possível obter argamassas com resistências à compressão aos 28 dias de 21 MPa a 37 MPa para vários níveis de relação água/cimento em até 30 % de substituição de cimento Portland por RPT. Dessa forma, é possível produzir argamassas econômica e ambientalmente viáveis, a partir da substituição parcial de cimento Portland por RPT, nas dosagens estudadas. As análises de DRX e de MEV indicaram a presença do quartzo, da calcita, da etringita, da portlandita, silicatos e porosidade em amostras de argamassas selecionadas, de modo que foi possível relacionar as mesmas com a resistência à compressão das argamassas.
6

Conception, production et qualification des briques en terre cuite et en terre crue / Conception, production and qualification of fired and unfired clay bricks

El Fgaier, Faycal 12 December 2013 (has links)
La réduction de la consommation énergétique dans le secteur de bâtiments présente aujourd’hui une priorité primordiale dans les politiques des pays industrialisés. En France, le secteur du bâtiment consomme environ 43 % de l’énergie finale et contribue pour près d’un quart aux émissions nationales de gaz à effet de serre [ADEME]. Il se positionne comme un acteur clé pour parvenir à résoudre les inquiétants défis environnementaux auxquels nous devons faire face. Face à ces véritables défis, l’augmentation des niveaux d’exigence des réglementations thermiques s’est poursuivie et intensifiée pendant les 40 dernières années, jusqu’à la naissance de la réglementation thermique 2012, qui a permis de construire des bâtiments basse consommation (BBC) qui équivaut à 50 kWh/m².an. Cette nouvelle réglementation plus exigeante constitue une incitation forte à l'innovation des matériaux, produits et systèmes d'enveloppe. Dans ces conditions, l’amélioration des performances hygrothermiques des matériaux de construction aura des retombées économiques et environnementales conséquentes. C’est dans ce contexte que ce travail a été mené. Il vise à étudier et à améliorer les performances des produits de l’entreprise Briqueteries du Nord (BdN). Il est réparti sur deux axes principaux : le premier consiste à l’étude de l’inertie thermique et du pouvoir hygroscopique des briques en terre crue. Le second axe vise à élaborer des solutions possibles concernant l’amélioration de la résistance thermique des briques en terre cuite. Ce travail de recherche a été réalisé au laboratoire de l’Ecole Centrale de Lille avec une étroite collaboration avec l’université d’Artois et l’entreprise (BdN) / Nowadays, the reduction of energy consumption in buildings industry represents a major issue in industrialized countries’ policies. In France, the building sector consumes about 43% of final energy and accounts for nearly a quarter of the national emissions of greenhouse gas emissions [ADEME]. It is considered as a key factor to overcome the environmental challenges we have to face.In front of these significant challenges, the thermal regulations requirements were seriously intensified during the last 40 years until the notification of the thermal regulation 2012. This latter enable the construction of low energy buildings (BBC) whose consumption is equivalent to 50 kWh/m² per year on average. This new regulation provides a strong incentive for innovation of materials, products and envelope systems. Under these conditions, improving hygrothermal performance of building materials will allow a substantial economic and environmental benefits. This work was conducted in this context. It aims to study and improve the performance of the company Briqueteries du Nord (BdN) products. It is divided in two main axis: the first consists on studying the thermal inertia and hygroscopic capacity of unfired clay bricks. However, the second axis aims to develop possible solutions for improving the thermal resistance of fired clay bricks. This research was conducted in the laboratory of the Ecole Centrale de Lille with close collaboration with the University of Artois and the BdN company
7

Restaurace a zázemí ČRS Lačnov / Restaurant and facilities for ČRS Lačnov

Štěpánová, Martina January 2018 (has links)
The subject of this thesis is the process of building technical part of the design documentation for the realization of a newly-built restaurant and facilities for Czech fishing union in the village Lačnov. The building consists of two objects interconnected by a connecting neck. The ground floor of the building with a flat roof is used as a restaurant. The restaurant is wheelchair accessible. Public entrance is from the southern side. The entrance for the staff and the supply will be from the east side. Facilities for staff and technical facilities there is in the northern part of the building. On the second floor there is an office, a meeting room and a training room for the Czech fishing union. In the second object with a gabled roof is an apartment for a fishing man and a shop with small fishing equipment. There is also a showers and toilets for the disabled. The technical background is situated in the attic. The house is based on strips foudations. Vertical loadbearing structures above ground are made of Porotherm system, external walls of the basement are made of prefabricated concrete shuttering blocks. Horizontal structures are designed as a monolithic reinforced concrete slab. Building is insulated. Part of the external wall finish are made of silicone plaster and part of it consists of ventilated facade with timber cladding.
8

Bydlení v soudobém městě - architektonicko urbanistická studie využití Kohnovy cihelny v Brně / Living in a city of nowadays - architectural and urban redevelopment of Kohn's brickyard in Brno

Vašáková, Dagmar January 2012 (has links)
Interest about living in the city is increasing and people look suitable sites for newconstruction. Boundary of these good places expand into the landscape. Undeveloped areas have become valuable goods and it is important to build up the appropriate form of building with critical density, which will provide new space for living, but also contribute to raising living standards and it elevate all surrounding area. Variable and flexible solution of my architectural and urban design fights with evacuation people into urban sprawl and try put there quality housing to the city center and try to be a timeless concept,which will be able to respond to different human rights requirements and wishes. The built up area will be created by grouping the proposed houses and residential houses into blocks. Individual detached houses are designed in a range of four sizes for satisfy of people who require small houses and for people which findmore comfortable living. Different sizes of houses could satisfy both seniors and young couples and families with children and the solution ensure local settlement by people of all ages and this creates a healthy demographers structure for place.
9

Centrum volnočasových aktivit / Center of leisure activities

Kaňovský, Michal Unknown Date (has links)
This diploma thesis presents a project documentation for construction of a center of leisure activities. It's construction site located on the outskirts of town Třebíč, "Na Kopcích" street. The building is composed from the two visual and three service parts which are connected to each other. On the left side in first floor there is a bowling with services and the second floor will serve for sport activities of jumping, spinning or relax massages. On the right side of building will be usable for education or for leisure activities. The building is designed as a two floors with partial basement. The construction system is formed by longitudinal wall system with precast hollow core slab or reinforced concrete slab. The structure is based on strip foundations with walls of permanent formwork. External wall is based on clay brick of therm type. The staircase is designed as prefabricated element or cast-in-place reinforced concrete. The roof is constructed as warm flat green roof with expanded polystyrene with screed to fall.
10

Development of product quality management guidelines for informal small-scale brick manufacturing enterprises in Dididi, Limpopo Province, South Africa

Matsiketa, Khensani Eullen 18 May 2018 (has links)
MESMEG / Department of Mining and Environmental Geology / Although clay brick manufacturing has been going on for many years in South Africa, informal small-scale clay brick manufacturing enterprises are not officially regulated. Consequently, informal brick makers in the study area do not adhere to the demanding requirements of the South African National Standards for burnt clay masonry. Therefore, their clay bricks lack uniformity in terms of quality. Preliminary work revealed that over time, buildings constructed with these bricks develop cracks, thereby compromising safety. The importance of product quality management is not well understood in the informal brick manufacturing enterprises. As a result, they do not have any product quality management guidelines. The main purpose of this research was to develop the product quality management guidelines for ensuring quality in small-scale brick making enterprises in Dididi area. The specific objectives were to characterize the raw materials for clay brick manufacturing, identify and assess the technical problems of clay brick production, analyse the process of clay brick production and determine areas where product quality improvement is warranted. The research involved fieldwork which included soil sampling, analysis of clay brick production through the use of questionnaires and onsite observation of the production process, collection of samples of burnt bricks which were examined for compressive strength, water absorption as well as dimension measurements. These were then compared with the prescribed quality standards. Laboratory analyses of samples of raw materials were conducted and these included sieve analysis which was conducted in order to establish the particle size distribution of the raw materials; Atterberg limit tests were conducted in order to establish the physical characteristics of the soil. Chemical and mineralogical analyses were carried out to determine the chemical and mineralogical composition of the soil using XRF and XRD respectively. The textural characterisation of the material revealed abundance of sand sized particles and significantly low amounts of clay and silt. The plasticity of the soil used for bricks manufacturing in the study area was found to be ranging from slight to medium plasticity. Chemical analysis showed elevated silica contents with minor amounts of alumina and iron oxide. XRD analysis revealed the dominance of non-clay minerals with the highest concentration of quartz. The average compressive strengths of the tested brick samples for site A was 3.8, and 2.9 and 3.8 MPa for sites B and C respectively. The water absorption of the bricks was 13.5, 15.0 and 16.1% for samples from Site A, B and C respectively. The bricks dimensions met the recommended standards although their sizes were not uniform. v The survey conducted on brick manufacturing process revealed that the technical inefficiencies were mostly influenced by human and mechanical factors as well as the material inappropriateness. The production process was found to be too manual and labour intensive. Selection of the raw materials for brick manufacturing was based on indigenous knowledge and experience and most of the brick manufacturers lacked the prerequisite experience for making quality bricks. On the basis of the results of this research, it can be concluded that the materials used for manufacturing of clay bricks in Dididi are not well suited for making good quality bricks due to the reduced plasticity of the soil and the high concentration of quartz. These render the bricks brittle. It was also concluded that the production process also contributes to the poor quality of the bricks as the nature of the process was too manual. Selection of materials based merely on knowledge and experience and no scientific tests resulted in selection of inadequate materials which in turn affect the quality of the final bricks. It is therefore recommended that plastic clays be added to the raw clay materials to enhance its moulding property. In addition, materials such as internal fuels and anti-shrinkage materials should be incorporated into the process cycle to prevent cracking during drying and firing. Based on the findings of the analysis of the production process, it is recommended that mechanized techniques be employed in the operation and awareness training conducted to improve the understanding and skills of the brick manufacturers and to ensure production of good quality bricks. / NRF

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