Dissertations / Theses on the topic 'Interlocking blocks'

A novel way to ensure stability of mortarless structures – topological interlocking – is examined. In this type of interlocking the overall shape and arrangement of the building blocks are chosen in such a way that the movement of each block is prevented by its neighbours. (The methodological roots of topological interlocking can be found in two ancient structures: the arch and the dry stone wall.) The topological interlocking proper is achieved by two types of blocks: simple convex forms such as the Platonic solids (tetrahedron, cube, octahedron, dodecahedron and icosahedron) that allow plate-like assemblies and specially engineered shapes of the block surfaces that also allow assembling corners. An important example of the latter – so-called Osteomorphic block – is the main object of this research with some insight being provided by numerical modelling of plates assembled from tetrahedra and cubes in the interlocking position. The main structural feature of the interlocking assemblies is the need of the peripheral constraint (for the Osteomorphic blocks this requirement can be relaxed to uni-directional constraint) to keep their integrity. We studied the least visible constraint structure – internal pre-stressed cables which run through pre-fabricated holes in Osteomorphic blocks. It is shown that the pre-stressed steel cables can provide the necessary constraint force without creating appreciable residual stresses in the cables, however the points of connection of the cables are the weakest points and need special treatment. The main mechanical feature of the interlocking structures is the absence of block bonding. As a result, the blocks have a certain freedom of translational and rotational movement (within the kinematic constraints of the assembly) and their contacts have reduced shear stresses which hampers fracture propagation from one block to another. These features pre-determine the specific ways the interlocking assemblies behave under mechanical and dynamic impacts. These were studied in this project and the following results are reported. As the blocks in the interlocking structure are not connected, the main issue is the bearing capacity. The study of the least favourable, central point loading in the direction normal to the structure shows elevated large-scale fracture toughness (resistance to fracture propagation). However when the central force imposes considerable bending the generated tensile membrane stresses assist fracturing of the loaded block. Prevention of bending considerably enhances the strength therefore the most efficient application of the interlocking structures would be in protective coatings and covers. Furthermore, proper selection of the material properties and the interface friction can increase the system overall strength and bearing capacity. The results of the computer simulations suggest that both Young’s modulus and the friction coefficient are the key parameters whose increase improves the bearing capacity of topologically interlocking assemblies.

Seismic Design Manual for Interlocking Compressed Earth Blocks Nicholas Edwards Kennedy This thesis presents a comprehensive seismic design manual to be used to design and construct simple Interlocking Compressed Earth Block (ICEB) structures in seismically active regions. ICEBs are earth blocks made primarily of soil and stabilized with cement. They have female and male stud mechanisms designed to interlock when stacked, eliminating the need for mortar. The blocks can accept reinforcement and grout after they are placed. While ICEB construction is similar to conventional masonry construction, current design code standards for masonry only partially capture the actual behavior of ICEB structures. This thesis seeks to supplement the existing masonry design procedures and tailor them for use with ICEBs. Additionally, this paper presents a preliminary design of ICEB shear walls for a disaster reconstruction project in the Philippines. While many structures in Southeast Asia and the Malay Archipelago are constructed from earthen blocks, very few are engineered. Of those that are, a lack of formal design guidance specific to ICEB construction leaves most engineers and designers with conventional concrete masonry design practices, some of which are not applicable for use with ICEBs.

Solid concrete Lego blocks can be used as temporary retaining wall systems or as wall separators between different materials such as sand, salt, compost, etc. The advantage of concrete blocks is that you can create temporary constructions. It is easy to move or expand the constructions when no casting is required between the blocks. The purpose of this study is to make models in the Finite Element (FE) software Abaqus/CAE that can be used for calculations of the capacity for interlocking blocks. FE method is an approximate method for solving differential equations. As the concrete blocks are stacked without casting, it is important to find out the construction’s load capacity when it is subjected to a horizontal load. Several types of structures have been modeled in the FE program Abaqus/CAE. These FE models were created with boundary conditions consisting of springs and a pinned connection that allows rotation.The evaluation has been focused on rotating the interlocking blocks. With the help of the FE models, reaction forces have been calculated. The FE results in term of reaction forces have been compared with hand calculations made ​​for the same models. Moreover, a wall and a wall with lateral supports have been simulated to determine the horizontal reaction force for the interlocking concrete blocks.
Massiva Lego betongblock kan ändvänds som tillfälliga stödmurar eller vägg avskiljare för olika material som salt, kompost, sand mm. Fördelen med betongblocken är att man kan skapa tillfälliga konstruktioner. Det är lätt att flytta eller bygga ut konstruktionen när ingen fog krävs mellan blocken. Syftet med denna studie är att skapa modeller i Finita Element (FE) programmet Abaqus/CAE som kan senare användas för beräkning av kapaciteten för sammankopplade block. FE Metoden är en approximativ metod för att lösa differential ekvationer. Eftersom betongblocken är staplade på varandra utan fog är det viktigt att ta reda på konstruktionens lastupptagnings förmåga när den är belastade med horisontalkrafter. Flera typer av konstruktioner har modellerats i FE programmet Abaqus/CAE. Dessa FE modeller har skapats med randvillkor som består av fjädrar och fasta lager som tillåter rotation. Utvärderingen har gjorts med fokus på vältningen i betongblocken. Med hjälp av dessa FE modeller har reaktionskraften tagits fram. FE resultaten i form av reaktionskrafter har sedan jämförts med handberäkningar gjorda för samma modeller. Vidare har en vägg och en vägg med sidostöd FE modellerats för att utvärdera horisontala deformationsegenskaper.
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This thesis examines the use of diagonal tension (shear) testing to determine factors affecting shear strength of Interlocking Compressed Earth Block (ICEB) panels. This work expands on the current information available about strength properties of ICEB assemblies, which are dry-stacked, as opposed to having mortared beds. Variables such as block strength, grout strength and grouting pattern can influence the results of these types of tests and are examined in this investigation. To study variables affecting diagonal shear strength, 9 panels were tested, consisting of blocks produced by a manual block press. Strength testing was adopted from common ASTM standards to determine constituent material properties. A modified version of ASTM E519 test procedure is used to perform diagonal tension testing. Imaging analysis, using a high resolution camera, was run simultaneously during testing to capture displacement histories of select panels. It was determined that both block and grout strength significantly affect the shear strength of ICEB panels. Additionally, vertical grouting and block type also have a strong influence. Imaging analysis results confirm that the dominant failure mode in ICEB panels is bed joint sliding both pre and post peak load, with noticeable displacements at head joint locations on a few panels. Lastly, diagonal cracking along the block face was noticeable on several panels following peak load. Further testing remains to determine other factors affecting shear strength, namely, the application of normal pre-compression loads to the panel.

This thesis investigates the tensile performance of unconfined lap splices in specimens constructed from interlocking compressed earth block (ICEB) units. All lap splice specimens were constructed from hollow ICEB half units with one side grouting channel. ICEB units used in this research were exclusively produced from the Soeng Thai Model BP6 block press. The BP6 block press is currently manufactured in Thailand under the guidance and direction of the Center of Vocational Building Technologies (CVBT). All ICEB units and grout constructed for this research were created from mix proportions of soil, sand, cement, and water. Rebar bar sizes were restricted to M10 (#3) and M13 (#4) for all lap splice specimens due to the limited area of the hollow 2-inch diameter rebar cavity of the ICEB unit. The limited size and strength of the ICEB units also made the use of larger bar diameters impractical. Three ICEB unit types of varying strengths (3.78 MPa, 7.81 MPa, and 11.38 MPa) and three grout types of varying strengths (1.35 MPa, 7.47 MPa, and 15.50 MPa) were developed and used to construct all specimens. The measured ICEB lap splice specimen strengths were compared against the predicted strength calculated from the Masonry Standards Joint Committee (MSJC). Findings suggested that the MSJC design equation did not adequately predict the lap splice strength of specimens, particularly for specimens constructed from weaker materials. The measured ICEB lap splice results were used to create a new ICEB lap splice design equation. This paper also investigates the compressive performance of fully grouted ICEB prisms constructed from the range of ICEB unit and grout strengths stated above. Findings suggested that the compressive strength of fully grouted ICEB prisms were exclusively controlled by the compressive strength of the ICEB units used to construct the prism. The strength of the grout had no discernable effect on the strength of the fully grouted prism. A design equation was proposed to calculate prism strengths based on measured strength results of ICEB units.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-06-27T17:24:22Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Maria Victória Leal de Almeida Nacimento (2016).pdf: 1980230 bytes, checksum: eef736353b0156d4355d07d1b2ad6f70 (MD5)
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A utilização de resíduos em materiais cimentícios, tem sido desenvolvida para melhorar a qualidade ambiental, diminuindo os resíduos gerados. O RPP é um resíduo industrial produzido em grande escala pela indústria cerâmica, ele foi utilizado nesse trabalho sendo incorporado em blocos intertravados de concreto. Os blocos intertravados de concreto foram escolhidos dentre os materiais cimentícios, por não ter sua trabalhabilidade comprometida, quando se trata de adicionar um material pulverulento, pois é produzido por vibro-compressão. Foi realizada a otimização do empacotamento dos agregados, para a produção dos blocos intertravados de concreto, através de método matemático. Também foi otimizada, através de método experimental a relação água/cimento. O traço de referência, encontrado após as otimizações, foi 1: 2,68: 2,32 (cimento: areia: pedrisco), com relação água/cimento de 0,45, atendeu as especificações da NBR 9781 (ABNT, 2013), com relação a resistência à compressão. A partir do traço de referência foi realizado o empacotamento matemático para a incorporação do RPP. O resíduo foi considerado como agregado no empacotamento, ele foi incorporado nas seguintes porcentagens: 3% de RPP, 6% de RPP, 9% de RPP, e 12% de RPP, afim de avaliar a influência do resíduo nos blocos intertravados de concreto, nas propriedades do estado endurecido. A presença do RPP, reduziu a absorção de água tendendo a trazer para o admitido pela NBR 9781 (ABNT, 2013), manteve a resistência a abrasão de acordo com as especificações da NBR 9781 (ABNT, 2013), embora tenha prejudicado a resistência a compressão, sendo promissor a sua utilização, em blocos intertravados de concreto, em situações onde não há tráfego de veículos, como em: passeios públicos, praças, parques infantis, áreas que necessitem de drenagem. O traço com a incorporação do resíduo, que de uma forma geral obteve os resultados mais satisfatórios foi o traço 2 (3% RPP), que apesar da resistência à compressão média ter sido de 14,26 MPa menor que o especificado pela norma, apresentou uma taxa de absorção média de 6,60%, e em relação a resistência à abrasão apresentou uma cavidade média de 17,50 mm.
To incorporate residues in cimentitious materials has been developed to improve the environmental quality, reducing the amount of disposed residues. The ceramic porcelain industry generates a large amount of porcelain tile polishing residue. This work proposes to incorporate this tile polishing residue in concrete interlocking blocks. The concrete interlocking blocks were chosen due to the addition of a powder material not prejudice their workability, once they are molded by vibrocompression. It was determined the best packaging by a mathematical method. The water-cement ratio was also optimized by the experimental method. The achieved reference mix proportion after all optimizations was 1:2.68:2.32 (cement: sand: gravel) with ratio water-cement ratio 0.45. The compressive strength of the reference mix proportion is according to the NBR 9781 (ABNT, 2013). In the sequence, based on this reference mix, the incorporation of the residue was also mathematically optimized. The residue was considered as an aggregate on the packaging method. The residue was incorporated at the following percentages: 3%, 6%, 9% and 12% in order to evaluate its influence on the hardened state properties of the concrete interlocking blocks. The presence of the tile polishing residue reduces the water absorption, tending to bring the values to the admitted one by the NBR 9781. The abrasion resistance was in agreement with the NBR 9781 (ABNT, 2013). However, the compressive resistance was reduced, limiting the applications of the concrete interlocking blocks with the addition of tile polishing residue where there is no vehicle traffic, as in public footpaths, parks, playgrounds or areas requiring drainage. In a general way, the most satisfactory result among the evaluated mixes incorporating tile polishing residue was to the mix 2 (3% of residue). Despite the average compressive strength was 14.26 MPa lower than the specified by the standard, this mix presented the average absorption of 6.60% and 17.50 mm as a medium cavity liner in the abrasion resistance test.

Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2016-04-15T18:58:56Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação-FINAL-ALCANTARA-(2015).pdf: 5450939 bytes, checksum: 48870216bb757bd8e071283661594dc0 (MD5)
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CAPES
Peças de concreto intertravadas para pavimentação (pavers) coloridas com pigmento de óxido de ferro (vermelho) são utilizadas em projetos de urbanização. Entretanto, esse tipo de pigmento, além de encarecer de 20 a 30% o valor das peças, prejudica as propriedades dos concretos secos moldados sob vibrocompressão. Diante disso, propõe-se incorporar resíduo de cerâmica vermelha (RCV) como matiz colorimétrica em prol da redução de pigmento em pavers coloridos, tendo em vista também a possibilidade de melhoria de suas propriedades por efeitos filler e pozolânico. A fim de investigar o efeito do pigmento e do RCV no compósito estudado, as formulações foram: (a) traço padrão pelo método de dosagem da ABCP para blocos e pavers; (b) adição de pigmento ao traço padrão (2% e 4%); (c) substituição da areia média pelo RCV no traço padrão (50%, 75% e 100%); (d) adição de RCV ao traço padrão (20%, 30%, 40% e 50%); (e) adição de pigmento (2%) e RCV concomitantemente ao traço padrão (20%, 30%, 40%, 50%, 100% e 150%). Para todos os traços (exceto aqueles das formulações de substituição), foi feita a correção do consumo de cimento em relação ao traço padrão. Resistência à compressão, absorção de água e resistência à abrasão foram avaliadas de acordo com a norma NBR 9781:2013; além disso, foi realizada uma avaliação das cores dos compósitos desenvolvidos por inspeção visual. Pastas de cimento vibroprensadas com baixa relação água-cimento (padrão, 3% pigmento, 15% RCV e 3% pigmento – 15% RCV) também foram moldadas para avaliações de cunho microestrutural, cristalográfico e de análise térmica das reações de hidratação dos sistemas. O traço padrão foi 1:2,29:1,76:0,95 (cimento:areia média:areia muita grossa:pedrisco) com relação água-materiais secos 0,80. De uma maneira geral, adições de apenas pigmento (2% e 4%) reduziram em até 73% a resistência à compressão do paver padrão cinza (sem adições). Redução nos produtos de hidratação (CH e C-S-H) foram observadas. As substituições de areia média pelo RCV também foram prejudiciais a esse sistema. Já as adições de apenas RCV, bem como as de RCV concomitantemente com pigmento foram positivas em ganhos ou manutenção de propriedades (resistência à compressão, absorção de água, resistência à abrasão e cor) em relação ao paver padrão colorido (4% de pigmento), destacando-se a formulação 2% de pigmento e 50% de RCV. Assim, a adição de RCV é uma possibilidade técnica promissora, sustentável e economicamente viável na fabricação de pavers avermelhados.
Concrete interlocking blocks colored with pigment iron oxide (red) are used in urbanization projects. However, that kind of pigment increases around 20 to 30% the value of the pavers, as well as affect the properties of the dry concrete molded by vibrocompression. Therefore, it is proposed to incorporate red ceramic waste (RCW) as colorimetric hue in order of pigment content reduction in colored pavers, considering also the possibility of improving their properties by filler and pozzolanic effect. In order to investigate the effect of pigment and RCW in the studied composite, the formulations were: (a) reference paver designed by ABCP method for blocks and pavers; (B) adding pigment to the reference paver (2% and 4%); (C) substitution of medium sand by RCW in the reference paver (50%, 75% and 100%); (D) adding RCW in the reference paver (20%, 30%, 40% and 50%); (E) addition of pigment (2%) and RCW concurrently in the reference paver (20%, 30%, 40%, 50%, 100% and 150%). For all mixtures (except those of replacement formulations), it was made the correction in cement consumption related to the reference mix proportion. Compressive strength, water absorption and abrasion resistance were measured according to the ABNT NBR 9781: 2013 standards; besides that, the color and texture of all manufactured formulations were observed by visual inspection. Cement pastes made by vibrocompression with low water-cement ratio (reference paste, 3% pigment, 15% RCW and 3% pigment RCW - 15% RCW) were also molded for microstructural, crystallographic and thermal analysis of systems hydration reactions. The reference mix proportion was 1:2.29:1.76:0.95 (cement: medium sand: thick sand: gravel) with ratio water-dry material 0.80. In general, additions of only pigment (2% and 4%) up to 73% reduced the compressive strength of the reference paver (no additions). Reduction in hydration products (C-S-H and CH) was observed. The substitution formulations of medium sand by RCW were also harmful to the systems. Additions of only RCW and RCW concomitantly with pigment were positive in gains or maintaining of properties (compressive strength, water absorption resistance and abrasion resistance) compared to the reference colored paver (4% pigment), especially the formulation of 2% pigment and 50% RCW. Thus, the addition of RCW is a promising, economic and sustainable technique in the production of red pavers.

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Esta dissertação tem por objetivo comparar economicamente o pavimento de concreto asfáltico e de blocos intertravados de concreto na pavimentação urbana da Avenida Severo Dullius, considerando os custos das soluções propostas pelos métodos. A avenida em estudo é uma das principais vias radiais que compõe o anel viário que dá acesso ao Aeroporto Internacional Salgado Filho, é tida como essencial dentro do plano de mobilidade urbana do município de Porto Alegre/RS, localizada em zona urbana alagadiça, com subleito constituído de solos de baixo poder de suporte e tráfego comercial pesado. O dimensionamento foi realizado para um trecho 2,3 Km e, contou com estudos geotécnicos, com intuito de caracterizar física e mecanicamente o solo do subleito, considerou-se a contagem e classificação do tráfego atuante na via. Em seguida, foi analisado o comportamento estrutural desses pavimentos urbanos na referida situação e apresentados os métodos construtivos adequados e recomendados. Aplicou-se para o pavimento em concreto asfáltico o método de dimensionamento de pavimento flexíveis – DNER atual DNIT, e para o bloco intertravado de concreto empregou-se o método da ABCP (1998). Para permitir a comparação técnica e financeira entre os pavimentos, foram consideradas suas características estruturais e os respectivos períodos de projetos. Contabilizaram-se os custos da implantação e da conservação. Com os orçamentos disponíveis, efetuou-se uma comparação de serviços com o objetivo de identificar sua viabilidade econômica, propondo o assim o pavimento adequado para a via selecionada. Concluiu-se que para este estudo a utilização do bloco intertravado de concreto como solução final em função do custo comparado, apresentou-se uma economia de 16,93% no custo final da implantação, portanto economicamente mais vantajosa em relação ao concreto asfáltico. Diante disto, concluiu-se também, que uma análise econômica de um pavimento rodoviário, deve-se sempre abordar todos os custos e benefícios pertinentes, considerando todas as fases de sua implantação.
This dissertation aims to compare economically the asphalt concrete and interlocking concrete blocks in the urban paving of Severo Dullius Avenue, considering the costs of the solutions proposed by the methods. The avenue under study is one of the main radial roads that makes up the ring road that accesses the Salgado Filho International Airport, and it is considered imperative to the urban mobility plan of the city of Porto Alegre / RS, located in and urban swamp area, with subsoil consisting of low support power soils and heavy commercial traffic. The sizing was carried out for a 2.3 km stretch, and it was based on geotechnical studies in order to physically and mechanically characterize the subsoil soil, considering the counting and classification of the traffic acting on the road. Next, the structural behavior of these urban pavements in the mentioned situation was analyzed and the suitable and recommended construction methods were presented. The method of sizing of flexible pavement – DNER current DNIT was applied to the asphaltic pavement, and the ABCP (1998) method was used for the interlocked block of concrete. In order to allow the technical and financial comparison between the floors, their structural characteristics and the respective project periods were considered. The costs of implementation and conservation were taken into account. With the budgets available, a comparison of services was carried out in order to identify their economic viability, thus proposing the adequate pavement for the selected route. It was concluded for this study that, as a final solution, the use of the interlocked concrete block compared with the concrete, showed a saving of 16,93% in the final cost of the implantation, thus economically more advantageous in relation to the asphalt concrete. In view of this, it was also concluded that an economic analysis of a road pavement should always address all relevant costs and benefits, considering all phases of its implementation.

O concreto seco, também chamado de concreto sem abatimento (no-slump) é utilizado na produção de artefatos de cimento, como por exemplo em peças de concreto para pavimentação, blocos para alvenaria e tubos de concreto e ainda como camada de subbase de pavimentos com a técnica de concreto compactado a rolo. A técnica de conformar concretos com reduzido teor de umidade através de equipamentos que aplicam simultaneamente compressão e vibração é amplamente utilizada na produção de artefatos de concreto, como as peças de concreto para pavimentação intertravada. Para as peças de concreto o desafio é ainda maior, pois as especificações de resistência característica à compressão podem chegar a 50 MPa. A principal característica do concreto seco é o baixo teor de água e elevada coesão, necessitando de energia de compactação e vibração para a eliminação de vazios e o concreto assumir a forma desejada. Esta técnica permite a desfôrma imediata, que garante elevada produtividade e consequente diminuição dos custos de produção. Já a compactação permite obter componentes de concreto com menor consumo de cimento se comparados ao concreto plástico. Diferentemente de toda literatura e metodologias de dosagem encontradas para o concreto plástico, o concreto seco encontra barreiras técnicas para a aplicação de metodologias que otimizem sua dosagem, em formulações empíricas que não levam em conta de forma adequada as características dos agregados, características estas diretamente ligadas à compacidade das peças, que por sua vez tem grande influência nas características do produto final. Além disto, há poucos estudos do comportamento reológico do concreto seco, que influenciam a fluidez e coesão da do concreto e que irão determinar a produtividade e qualidade da produção. Dessa forma, neste trabalho é apresentado uma metodologia para caracterização do concreto seco nos estados fresco e endurecido que permite o desenvolvimento sistemático de formulações com maior facilidade de compactação e que também resulte na melhoria do desempenho das peças e diminuindo a necessidade de testes em escala real. O método se baseia em produzir em laboratório um corpo de prova que reproduz as condições de moldagem de uma vibroprensa, eliminando-se a variável da vibração e padronizando as condições de compressão. Nos corpos-de-prova são avaliadas características nos estados fresco e endurecido, além de aspectos do comportamento reológico do concreto, através de técnicas de reologia compressiva. Para aferir a metodologia foram utilizadas amostras de referência produzidas em uma fábrica de peças de concreto. Com a metodologia proposta, foi possível atingir 90% da resistência mecânica das peças produzidas em uma vibroprensa de alta compactação. Sendo assim esta metodologia poderá ser utilizada em estudos de dosagem de concreto seco, portanto o trabalho desenvolvido é indicado na utilização de dosagens de concreto seco, obtendo-se maior ecoeficiência, a medida que otimiza o consumo de cimento da mistura e facilita o estudo de dosagem de materiais alternativos em substituição aos agregados convencionais.
The dry concrete, also known as earth moist concrete or no-slump concrete, is most used to manufacture precast concrete products, as paving blocks, masonry blocks and concrete tubes, and also in rolled compacted concrete pavement. Its most important property is the low water content, and it requires mechanical equipment for its compactation. Paving blocks are normally manufactured using vibrocompression equipment, which at the same time applies both compaction and vibration resulting in paving blocks with high durability and mechanical resistance. Even though this technique is highly used it still lacks studies on some important steps of the manufacturing process. The mix design techniques are mostly empirical and dont deeply consider the aggregate characteristics, that are connected with its compacity and, by that, the characteristics of the paving block. Also, there are only a few studies of the rheology characteristics of dry concrete, which relates with de manufacturing process and the easiness that the mix is compacted. So, the object of this study is to develop a dry concrete characterization methodology that allows the systematic development of mix designs that are easily compacted and also improves the performance of the paving blocks.

This thesis presents results from testing of interlocking compressed earth block (CEB) masonry shear walls. CEBs are low strength earth masonry units sometimes stabilized with cement or lime. The interlocking compressed earth blocks (ICEBs) used in this experiment are dry stacked interlocking hollow units, which can be reinforced and grouted after they are laid. Although significant research has been undertaken to optimize the material properties of CEBs, little has been done to investigate the performance of structural systems currently being built using this technology. Test results are reported for three 1800 mm x 1800 mm wall specimens constructed with cement stabilized ICEBs and subjected to cyclic in-plane lateral loading. Wall specifications were varied to identify the shear performance of partial and fully grouted walls, and to observe the performance of a flexure dominated wall panel. It was determined that the shear strength of fully grouted walls is significantly higher than that of partially grouted walls and calculation of capacity based on current ACI 530-08 masonry provisions significantly overestimates the shear strength of ICEB wall panels. Based on the observed performance, recommendations are made for limiting the calculated nominal shear strength in design. Results also indicate that calculations based on simple bending theory conservatively predict the flexural strength of a fully grouted ICEB wall. Discussion of ICEB material properties and recommendations for design and construction procedures are included.

Interlocking compressed earth blocks (ICEBs) are cement stabilized soil blocks that allow for dry stacked construction. The incomplete understanding of the inelastic performance of ICEB building systems limits widespread acceptance of this structural system in earthquake prone areas. This thesis presents results from an experimental program designed to explore the behavior of ICEB walls, built according to current design practice in Indonesia and Thailand, and subjected to out-of-plane loading. A total of five reinforced and grouted ICEB walls were constructed and tested. Results from experimentation show the current masonry design code, ACI 530, adequately predicts the yield strength of these walls. However, ACI 530 grossly over-predicts the ICEB wall stiffness. All tests showed flexural behavior and failure, except for one wall. A brittle failure was observed in one wall before reaching the predicted flexural strength, prompting a suggested maximum shear tie spacing. The testing results provide useful data for developing analytical models that predicts the seismic behavior of ICEB walls under out-of-plane loading. A moment-curvature relationship was developed that accurately predicts the behavior of these walls in the elastic range as well as the inelastic range. By comparing the data provided by two walls of similar sizes, one including a pilaster and one without a pilaster, insight into stiffener elements was gained. Analysis of these two walls provides a limit on the length and height of ICEB walls without stiffener elements to prevent significant structural damage during a seismic event. In all, conclusions based on experimental data from ICEB out-of-plane loading tests are aimed to provide suggestions for ICEB construction in areas of high-seismicity.

This thesis investigates the flexural behavior of interlocking compressed earth block (ICEB) shear walls. In-plane cyclic tests were conducted to evaluate the performance of three flexure dominant large scale ICEB specimens: a slim wall with a 2:1 height to width aspect ratio, a flanged wall, and a wall with an opening at the center. Following the experimental investigation, two types of analyses were conducted for calculating the ultimate strength of flexure dominant ICEB walls: a nonlinear static analysis model assuming lumped plasticity and a plastic analysis model. In addition, incremental dynamic analysis was conducted to address the seismic performance of flexure dominant ICEB buildings. Based on the database from the incremental dynamic analysis, the collapse potential of demonstration ICEB buildings were compared for the countries of interest.

Dentre a vasta gama de alternativas estruturais possíveis para a construção de pavimentos, os revestimentos com blocos pré-moldados de concreto têm sua aplicação consolidada em pavimentação de áreas portuárias. Além disso, em muitos países, este tipo de pavimento tem sido utilizado com sucesso em aplicações rodoviárias, aeroportuárias, em pátios industriais e em demais aplicações para tráfegos veiculares e de pedestres. No Brasil, no entanto, devido a insucessos em sua utilização, motivados, muitas vezes, pela inobservância de parâmetros técnicos relevantes a essa tecnologia, contribuíram para que este tipo de pavimento tenha sido subutilizado. Todavia, as recentes revisões nas normas nacionais que tratam deste tema, a criação de novas normatizações e a recente construção de importantes rodovias utilizando este tipo de revestimento, contribuem para o aperfeiçoamento de profissionais e a diminuição do prejulgamento desta tecnologia. Neste sentido, é de suma importância estudar o comportamento estrutural e funcional deste tipo de pavimento. De modo que, neste trabalho, foram estudadas quatro seções de dois trechos experimentais construídos entre julho e setembro de 2010. Foram realizadas avaliações destrutivas e não destrutivas para análise dos materiais, suas espessuras e confronto com os parâmetros construtivos oriundos do projeto e da literatura, bem como a verificação das condições para realização de retroanálise dos módulos de resiliência das camadas do pavimento. Os levantamentos deflectométricos apresentaram patamares muito elevados de deflexões reversíveis em todas as seções estudadas. Das aberturas de cavas e confronto com a estrutura de projeto, verificou-se incompatibilidades entre os materiais e espessuras das camadas do pavimento projetado x pavimento construído, destacando-se a condição verificada na camada de base por apresentar significativa desagregação do material, cujo projeto indicava utilização de concreto compactado com rolo (CCR), o que evidencia problemas no controle tecnológico dos materiais e falhas no gerenciamento da obra. Por meio das retroanálises foram verificadas diminuições significativas dos módulos de resiliência das camadas do pavimento, quando comparado com os parâmetros de projeto. Os índices de condições do pavimento (ICP) apontaram condições distintas nas seções avaliadas mesmo sujeitas ao mesmo tráfego de veículos.
Among the wide range of possible structural alternatives for the construction of pavements, interlocking concrete pavements are the orthodox solution for paving ports. Furthermore, in many countries, this type of pavement has been successfully used in highways, airport applications, in industrial areas and other applications for vehicular traffic and pedestrians. In Brazil, however, due to failures in its use, driven often by the lack of relevant technical parameters to this technology, contributed to the fact that this type of pavement has been misused. Although, recent reviews from the national standards that deal with this type of pavement, the creation of new standards and the recent construction of important highways using this type of structure, have contributed to the improvement of professionals and decreased the prejudice of this technology. In this sense, it is extremely important to study the structural and functional behavior of this type of pavement. Therefore, in this research it was studied two experimental sections built between July and September 2010 that carried out destructive and nondestructive evaluations for the analysis of materials, their thicknesses and constructive confrontation with the parameters derived from the project and the literature, as well verifying the conditions to accomplish the back calculation of the elastic modulus of the pavement layers. The displacement tests surveys demonstrated very high levels of reversible displacements in all studied sections. From the inspection pits openings and confrontation with the project structure, there is incompatibility between the materials and thicknesses of the layers of the designed pavement versus constructed pavement, the condition verified highlighting the base layer for introducing significant breakdown of the material, which design indicated use of roller-compacted concrete (RCC), which indicates problems in the quality control of materials and failures in the management. The back calculation showed that decreases were observed elastic modulus of the pavement layers when compared with the design parameters. Surveys concerning pavement condition index (PCI) showed different conditions for the evaluated sections even supporting the same traffic.

L’elaborato tratta gli impianti di segnalamento e sicurezza ferroviaria (IS), sia in linea che in stazione, descrivendo gli enti preposti all’esercizio e mettendo in risalto l’aspetto riguardante la sicurezza, esplicitando le tecniche di fail-safe, e le condizioni necessarie per garantirla. Vengono poi introdotti gli impianti centrali elettrici (ACEI) e descritti i relè da essi utilizzati, nonché le varie fasi di funzionamento di tali apparati per la circolazione in stazione. Si descrivono successivamente gli apparati centrali computerizzati (ACC o ACS) che ne rappresentano l’evoluzione tecnologica, sia in componentistica, che in logica, tramite rappresentazione dei relè in equazioni booleane in modo da conservare il principio di funzionamento degli impianti precedenti. Dopo aver introdotto i concetti necessari si fa un focus sul processo di verifica e validazione per applicazioni ferroviarie, sia a livello normativo, mettendo in risalto l’importanza assegnata al rispetto dei requisiti RAMS, che procedurale, esplicitando gli aspetti da tenere in considerazione per tale scopo. Il case study dell’attività di verifica e validazione riguarda l’introduzione del tasto di liberazione condizionato del blocco conta assi secondo uno schema di principio approvato dall’agenzia nazionale per la sicurezza delle ferrovie, descrivendo le varie tecniche atte ad eseguire tale processo, sia in ambiente simulato che reale.

In this thesis are solved the newly built 'hotel in Brno ". The building is freestanding. It has five storeys. The structural system is reinforced concrete skeleton. Columns in combination with masonry infill Porotherm. The building is based on the footings. The building has two height levels. The first is covered with a flat roof vegetation and the second single-roof bitumen sheets. The building is insulated contact system. On the first floor is a reception, restaurant with kitchen, fitness center and facilities for the hotel staff. The second floor of the portion used for guest accommodation. The second part is a cafe with cold kitchen and meeting room attached to the bar. In the third to fifth floors are guest rooms and technical background. On the fifth floor are apartments

Dissertação de Mestrado em Engenharia Civil - (área de especialização em Engenharia Rodoviária)
Actualmente, os pavimentos com blocos, sucessores das técnicas ancestrais da construção viária no antigo Império Romano, têm adquirido uma maior importância, que resulta da necessidade de utilização destes pavimentos nos mais diversos projectos de requalificação urbana em Portugal, nomeadamente, no Programa “Polis” e em outros projectos com objectivos semelhantes. A construção de pavimentos com blocos em Portugal, principalmente em granito, colocou em evidência as limitações das estruturas de pavimentos tradicionalmente utilizadas, nomeadamente de adequação à agressividade do tráfego. Estas limitações permitiram identificar as necessidades de melhoria e procurar uma abordagem mais adequada à realidade actual, quer nos processos de construção, quer nas metodologias de dimensionamento dos pavimentos. Um dos objectivos deste trabalho consistiu em reunir informação sobre as técnicas de construção de pavimentos com blocos, que se realizam um pouco por todo o mundo, assim como sobre as melhores regras construtivas, de modo a estabelecer um programa para a construção de trechos experimentais que permitisse adequar as técnicas usadas noutros países à realidade Portuguesa, com base no “estado da arte”. Na primeira metade da dissertação são expostos os conhecimentos assimilados de construção de pavimentos, na generalidade, e de pavimentos com blocos, em especial. Na segunda metade abordam-se os processos de construção, a partir dos resultados da componente experimental do trabalho, que se aplicaram posteriormente na obtenção de catálogos de dimensionamento para pavimentos com blocos de granito e de betão. O crescimento verificado nos últimos anos no uso de blocos de betão na construção de pavimentos confirma o interesse em incluir o estudo da utilização destes materiais em pavimentos no trabalho desta dissertação. Com esta dissertação pretendeu-se contribuir para o aprofundamento dos conhecimentos de construção e concepção dos pavimentos com blocos.
Block pavements, which result from the ancestral road construction techniques of the old Roman Empire, have acquired a higher importance as a result of the need to use these pavements in the most diverse projects of urban re-qualification in Portugal, namely in the "Polis" Program and in other projects with similar aims. The construction of block pavements in Portugal, especially using granite blocks, highlighted the limitations of the traditionally used pavement structures to withstand the present challenges, namely the high traffic wear factors. These limitations allowed identifying the need to improve and find a more adequate approach to the present reality, either in the construction process, or in the pavement design methodologies One of the objectives of the present work was to gather information about the construction techniques of block pavements that take place around the world, as well as the best construction rules, in order to establish a program for construction of real scale pavement trials, which would allow to adapt the techniques used in other countries to the Portuguese reality, based on the "state-of-the-art",. The first part of the dissertation presents the assimilated knowledge in terms of pavement construction, in general, and of block pavements, in particular. In the second part the construction processes, will be discussed, according to the experimental components of the work, which were subsequently applied in the completion of design catalogues of granite and concrete block pavements. The growth in the use of concrete blocks in the construction of pavements in the last years confirms the interest of including, in this dissertation, the study of the use of these materials in pavement construction. This dissertation intended to contribute to the knowledge increase in terms of construction and conception of block pavements.

Tese de Doutoramento em Engenharia Civil (área de especialização em Estruturas
Earth is still used as a building material to construct houses in Africa. One of the most common techniques is the masonry of sun dried or kiln fired mud bricks with earth mortar. Although this technique is cheap and allows the self-construction, the bricks vary largely in shape, strength and durability. This leads to weak houses which suffer important damage during floods and seismic events. A solution which has been proposed in the last decades is the use of drystack masonry with stabilized interlocking compressed earth blocks (ICEB). These blocks are manufactured by compacting cement stabilized earth in a manual or hydraulic press into a mould and then air cured for 28 days. The resulting blocks present uniform shapes, higher values of strength and durability and lower embodied energy than the traditional bricks. The material properties of ICEBs has been researched extensively, but little has been concluded with respect to the structural behaviour of these masonry dry-stack systems. Motivated by the above reasons, this work focused on the study of ICEBs to be used in dry-stack masonry of one storey houses in regions with moderate seismicity. Malawi was selected as the case study country. The mechanical characterization of the masonry was made by first studying the material properties of the blocks. Parameters such as compression and flexural strength, the Young’s modulus and compressive and tensile fracture energy have been determined through laboratory tests. In a second phase, masonry specimens were tested to determine the compressive strength, shear behaviour of the dry joints and shear behaviour of full scale walls. Finally, to study the behaviour of a real structure under seismic action, a small masonry mock-up of a house was tested on a shaking table. The results of the tests showed that it is possible to produce ICEBs of sandy soils with sufficient strength. The tests of shear walls revealed that the shear strength of this masonry is low, but comparable to that of other earthen walls. The walls also showed high values of ductility and behaviour factor. The shaking table test showed that the mock-up resisted without significant damage peak ground accelerations (PGA) of 0.2 g, which are equivalent to those expected for frequent earthquakes in Malawi. It also showed that moderate damage can be expected for rare earthquakes with PGAs of 0.3 g and that near collapse would occur at almost twice that value. The behaviour factor was of 1.5, which is the maximum permitted by the Eurocode 8 for unreinforced masonry. The knowledge gained in the several phases of this work was used to develop a manual for building ICEB houses.
A terra tem sido usada como material de construção para a edificação de casas em África. Uma das técnicas mais comuns é a alvenaria de tijolos de terra, secos ao sol ou cozidos em forno, com argamassa de terra. Embora esta técnica seja barata e permita a auto-construção, os tijolos variam muito de forma, resistência e durabilidade. Isto leva a casas de fraca qualidade, que sofrem danos importantes em caso de inundação ou evento sísmico. Uma solução que tem sido proposta nas últimas décadas é a alvenaria de blocos de terra compactada com sistema de encaixe (ICEB). Estes blocos são produzidos por compactação de terra estabilizada com cimento numa prensa manual ou hidráulica e são deixados a curar ao ar. Os blocos resultantes apresentam formas uniformes, valores de resistência e durabilidade superiores e energia incorporada mais baixa que os tijolos tradicionais. As propriedades dos ICEBs tem sido investigada intensivamente, mas pouco tem sido concluído em relação à definição do comportamento estrutural destes sistemas de alvenaria de junta seca. Motivado pelas razões acima expostas, este trabalho focou-se no estudo de ICEBs para serem utilizados em alvenaria de junta seca de casas com um andar em regiões de sismicidade moderada. O Malawi foi o país escolhido como caso de estudo. A caracterização mecânica da alvenaria foi conseguida estudando-se primeiro as propriedades materiais dos blocos. Foram determinadas experimentalmente várias propriedades mecânicas, tais como resistência à compressão e flexão, módulo de elasticidade, e energia de fratura em compressão e tração. Numa segunda fase, foram ensaiados provetes de alvenaria para caracterizar-se a resistência à compressão, comportamento ao corte das juntas secas e comportamento de corte de paredes à escala real. Finalmente, um pequeno modelo de uma casa foi ensaiado em mesa sísmica para se estudar o comportamento de uma estrutura real sob ação sísmica. Os resultados dos ensaios mostraram que é possível produzir ICEBs com resistência suficiente, a partir de solos arenosos. Os ensaios das paredes à escala real revelaram que a resistência ao corte da alvenaria é baixa, mas comparável à de outras paredes de terra. As paredes também apresentaram valores elevados da ductilidade e do fator de comportamento. O ensaio de mesa sísmica mostrou que o modelo resistiu sem danos significativos a acelerações pico do solo (PGA) de 0.2 g, que são equivalentes às esperadas em sismos frequentes no Malawi. Também se mostrou que podem ser esperados danos moderados para sismos raros com PGAs de 0.3 g e que o quase colapso só ocorreria para cerca de o dobro deste valor. O fator de comportamento foi de 1.5, que é o máximo permitido pelo Eurocódigo 8 para alvenaria não reforçada. O conhecimento obtido das várias fases deste trabalho foi utilizado para se desenvolver um manual para a construção de casas de ICEBs.

Yes
Experimental study of five full scale masonry wall panels subjected to prescibed pre-compressive vertical loading and increasing in-plane lateral loading is discussed. All five walls were constructed using interlocking mortarless load bearing hollow concrete blocks. The behaviour of wall in term of deflections along the wall height, shear strength, mortarless joint behaviour and local and overall failures under increasing in-plane lateral loading and pre-compressive vertical loading are reported and analysed. Simple strut-and-tie models are also developed to estimate the ultimate in-plane lateral capacity of the panel walls tested. The results indicate that, as the pre-compressive load increases, the in-plane lateral load capacity of walls increases. All walls tested failed due to diagonal shear and/or moderate toe crushing depending on the level of the pre-compressive load. The proposed strut-and-tie models were able to give reasonable predictions of the walls tested.

Student Number : 0100677A - PhD thesis - School of Civil and Environmental Engineering - Faculty of Engineering and the Built Environment
This thesis presents the findings on empirical study of dry-stack masonry. Dry-stack masonry refers to a method of building masonry walls, where most of the masonry units are laid without mortar in the joints. Of late (since mid eighties) in modern construction, dry-stacking or mortarless technology is increasingly becoming popular because of its advantages. The construction industry is acknowledging the need to accelerate the masonry construction process, as the traditional method is labour intensive and hence slower due to the presence of a large number of mortar joints. Early attempts were made to increase the size of masonry units (block instead of brick), thereby reducing the number of mortar joints, wherein the use of bedding mortar imposed constraints on the number of courses to be constructed in a day. Elimination of bedding mortar accelerates construction; thereby reducing cost, variation due to workmanship and generally small pool of skilled labour is required in dry stacking. Dry-stack masonry is a relatively new technology not yet regulated in the code of practice and therefore very limited information on the structural behaviour of the masonry is available. This project is based on the investigation of the HYDRAFORM dry-stack system, which utilises compressed soil-cement interlocking, blocks. The system is now widely used in Africa, Asia and South America. The main objective of the project was to establish through physical testing the capacity of the system to resist lateral load (e.g. wind load), vertical load and dynamic load such as earthquake loading. In the first phase of the project investigations were conducted under static loading where series of full-scale wall panels were constructed in the laboratory and tested under lateral loading, and others were tested under vertical loading to establish the mode of failure and load capacity of the system. Series of control tests were also conducted by testing series of wallettes to establish failure mechanism of the units and to establish the flexural strength of the system. Finally the test results were used for modelling, where load prediction models for the system under vertical loading and under lateral loading were developed. The theoretical load prediction models were tested against the test results and show good agreement. After the load capacity was established the next step in the study was to further improve the system for increased capacity particularly under dynamic loading. The normal Hydraform system was modified by introducing a conduit, which allows introduction of reinforcements. Series of dry-stack seismic systems were constructed and initially tested under static lateral loading to establish the lateral load capacity. The second Phase of the project was to investigate the structural behaviour and performance of the Hydraform system under seismic loading. A shaking table of 20 tonnes payload, (4m x 4m) in plan was designed and fabricated. A full-scale plain dry-stack masonry house was constructed on the shaking table and subjected to seismic base motions. The shaking table test was performed using sine wave signals excitations starting from low to very severe intensity. A conventional masonry test structure of similar parameters was also constructed on the table and tested in a similar manner for comparison. The tests were conducted using a frequency range of 1Hz to 12Hz and the specimens were monitored for peak accelerations and displacements. For both specimens the initial base motion was 0.05g. The study established the mode of failure of the system; the structural weak points of unreinforced dry-stack masonry, the general structural response of the system under seismic condition and the failure load. The plain dry-stack masonry failed at 0.3g and the conventional masonry failed at 0.6g. Finally recommendations for further strengthening of system to improve its lateral capacity were proposed.