Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2018-08-30T15:40:26Z No. of bitstreams: 2 Dissertação - Mirella Talitha Rocha - 2016.pdf: 5610966 bytes, checksum: a480f957a8e5ca103e387a6d96cdc48e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-09-03T11:46:56Z (GMT) No. of bitstreams: 2 Dissertação - Mirella Talitha Rocha - 2016.pdf: 5610966 bytes, checksum: a480f957a8e5ca103e387a6d96cdc48e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-09-03T11:46:56Z (GMT). No. of bitstreams: 2 Dissertação - Mirella Talitha Rocha - 2016.pdf: 5610966 bytes, checksum: a480f957a8e5ca103e387a6d96cdc48e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-08-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The use of alternative materials as subbases and bases stabilization is being increasingly in asphalt pavements, especially in areas with lack of granular materials. The chemical stabilization using additives such as Portland cement and hydrated lime is used since antiquity, with the aim of improving the geotechnical characteristics of natural materials. The treated soils exhibit complex behavior, influenced by several factors such as chemical reactions, soil types, added amount of stabilizing, moisture content and the time and type of curing. Generally, the procedure for determining the minimum lime or cement content to be added to the mixture refers to the initial estimate and attempts the standard recommendations to meet the parameters of mechanical tests, in order to define a minimum additive amount present resistance compatible with the paving design. The focus of this research was initially to analyze the dosage employed in the base layer of the GO-080 highway, in the stretch between Neropolis-GO and the BR-153 where the pavement structure consists of 20 cm thick granulometrically stabilized subbase, gravel laterite base with 20 cm thick and stabilized with 20% sand, 2% Portland cement (PC II-Z-32) and asphalt concrete surface with 5 cm thick. In addition, the aim was also to study the mechanical properties of natural gravel and their behavior when mixed with three levels (2%, 4% and 6%) of cement and hydrated lime. Therefore, laboratory tests for soil characterization, compaction tests on intermediate Proctor energy, determination of expansion and California Bearing Ratio, unconfined compression and resilient modulus of the molded mixture at the optimum moisture for three times cure (0, 7 and 28 days) were carried out. The resilient moduli results were evaluated by numerical analysis using KENLAYER software. To complement the analysis of strength parameters, diffraction X-ray and scanning electron microscopy tests were performed. The results show that for the studied soil, the chemical stabilization with lime contributed little to the increase of strength parameters, but the use of cement showed greater potential use. Differences on behavior observed in unconfined compression tests and dynamic triaxial were explained by changes that occur in the microstructure during the stabilization process. Finally, it is clear that the tropical soil stabilization process is complex, with over current mechanical tests, such as dynamic triaxial, and unconventional parameters for pavement soil analysis, such as water/cement ratio and porosity, should be analyzes incorporated in order to obtain more consistent results. / O emprego de materiais alternativos em sub-bases e bases está sendo cada vez mais frequente em pavimentos asfálticos, principalmente em regiões com ausência de materiais granulares. A estabilização química utilizando aditivos como o cimento Portland e a cal hidratada é empregada desde a antiguidade, com o objetivo de melhorar as características geotécnicas dos materiais naturais. Os solos tratados apresentam comportamento complexo, influenciados por diversos fatores como reações químicas, tipos de solo, quantidade adicionada de estabilizante, teor de umidade e o tempo e tipo de cura. Geralmente, o procedimento para determinar o teor mínimo de cal ou cimento a ser adicionado à mistura refere-se a uma estimativa inicial e segue as recomendações normativas para atender os parâmetros de ensaios mecânicos, de forma a definir um valor mínimo de aditivo que apresente resistência compatível com o projeto do pavimento. O foco desta pesquisa consistiu, inicialmente, em analisar a dosagem empregada na camada de base da rodovia GO-080, no trecho entre Nerópolis-GO e o entrocamento da BR-153, onde a estrutura do pavimento é constituída por sub-base estabilizada granulometricamente com 20 cm de espessura, base de cascalho laterítico com 20 cm de espessura e estabilizada com 20% de areia e 2% de cimento Portland (CP II-Z-32) e revestimento em concreto asfáltico de 5 cm de espessura. Além disso, objetivou-se, ainda, estudar as propriedades mecânicas do cascalho sem mistura e seu comportamento ao ser misturado com três teores (2%, 4% e 6%) de cimento e de cal hidratada. Para tanto, foram realizados ensaios laboratoriais para a caracterização do solo, ensaios de compactação na energia Proctor intermediária, determinação da expansão e do Índice de Suporte Califórnia, da resistência à compressão simples e módulo de resiliência das misturas moldadas na umidade ótima, para três tempos de cura (0, 7 e 28 dias). Para interpretação dos resultados em termos de módulo de resiliência, foram realizadas análises numéricas com o programa KENLAYER. Para complementação das análises dos parâmetros de resistência, foram realizados ensaios de difração de raios-X e microscopia eletrônica de varredura. Os resultados obtidos mostram que para o solo em questão, a estabilização química com cal pouco contribuiu com o aumento dos parâmetros de resistência. Já o uso do cimento apresentou maior potencial de utilização. As diferenças de comportamento observadas nos ensaios de compressão simples e triaxial dinâmico foram explicadas por mudanças que acontecem na microestrutura durante o processo de estabilização. Por fim, conclui-se que o processo de estabilização de solos tropicais é complexo, sendo que ensaios mecânicos mais atuais, como o triaxial dinâmico, e parâmetros não convencionais para análise de solos para pavimentação, como a relação água/cimento e porosidade, devem ser incorporados nas análises para a obtenção de resultados mais consistentes.

Este trabalho apresenta a avaliação dos efeitos da estabilização química com cal e cimento na condutividade hidráulica e resistência à compressão de um solo arenoso proveniente da Formação Botucatu (Estado de São Paulo, Brasil), com o objetivo de obter um material menos permeável e mais resistente. O projeto e análise de experimentos foram realizados através de um planejamento fatorial 3², com duas variáveis independentes: teor de umidade e porcentagem de estabilizante, variando em três níveis cada. Foi utilizado cal hidratada CH-III, cimento Portland CP II-Z32 e água fornecida pela concessionária local. Os ensaios de condutividade hidráulica (K) foram executados em permeâmetros de carga constante. Foram realizados ensaios de resistência a compressão simples (RC) após 7 e 28 dias de cura. As amostras de solo estabilizado e natural foram compactadas na energia Proctor Normal. Na avaliação da estrutura das amostras de solo estabilizado verificou-se a alteração da matriz de poros promovida pela adição de cal e cimento. Após a obtenção dos resultados, análises estatísticas possibilitaram avaliar os efeitos das variáveis independentes sobre o K e RC. Pelo método de superfície de respostas foi possível demonstrar o comportamento das misturas e identificar a tendência de alteração das propriedades. As amostras de solo-cimento alcançaram reduções de condutividade hidráulica de até 9,5 x 10-7 m/s e o menor valor experimental de K foi de 1,4 x 10-8 m/s. Os ensaios de RC, com 28 dias de cura, apresentaram acréscimo de resistência de até 5,1 MPa e os resultados obtidos possuem uma variação, aproximadamente, entre 0,1 e 5,1 MPa. O procedimento adotado permitiu avaliar a influência dos fatores e determinar as misturas ótimas para cada estabilizante. / A laboratory study was conducted to evaluate the effects of lime and cement stabilization over the hydraulic conductivity and unconfined compressive strength of a sandy soil from Botucatu Formation (São Paulo State, Brazil) with the intend to generate a less permeable and more resistant material. The experiment was performed using the technique of factorial design 3², with the two independent variables: moisture content and stabilizer percentage, varying on three levels each. Hydraulic conductivity (K) was measured in constant-head permeameters. Unconfined compressive strength (CS) was measured after 7 and 28 days of curing. The samples of stabilized and natural soils were compacted with the normal Proctor energy. The evaluation of the stabilized soil structure verified a pore matrix modification promoted by lime and cement addition. With the results of the characterization, statistical analysis allowed to assess the effects of the variable factors on K and CS. The response surface method was used to demonstrate the hydraulic and compressive strength behavior of the stabilized soil. The soil-cement hydraulic conductivity achieved reductions up to 9.5 x 10-7 m/s and the lowest K experimental value was 1.4 x 10-8 m/s. The compressive strength, with 28 days of curing, presented an increase in CS up to 5.1 MPa and the obtained results showed a range between 0.1 and 5.1 MPa. The adopted experimental procedure allows the assessment of the variables influence and the determination of the optimal mixtures for each stabilizer.

Soil-cement is an integral part of pavement design, especially in areas that are aggregate deprived, such as Mississippi. Current designs are reliant on the relationship of unconfined compressive strength (UCS) to other mechanical properties. The other properties discussed in this dissertation are Modulus of Elasticity (E), Indirect Tensile Strength (St), and Modulus of Rupture (MOR). This dissertation includes a comprehensive review of past design methods and mechanical property relationships. While some mechanical property relationships were shown to be well understood (i.e. St to UCS), others were not as accurate, especially for the later life mechanical properties (i.e. MOR to UCS and E to UCS). This dissertation investigates the Plastic Mold (PM) Compaction (PM) Device and its ability to measure mechanical property relationships (UCS, E, St) for soil-cement as well as different materials, such as lime stabilized subgrade and Cold in Place Recycling (CIR) stabilized with cement. These mechanical property relationships were compared to soil-cement beam specimens, which are capable of being tested for the four previously mentioned mechanical properties from an individual specimen. Finally to have a better understanding of the later life mechanical properties and their relationships, PM and beam specimens were exposed to elevated temperatures to forecast out how these properties interrelate over time. These mechanical property values and relationship were then compared to Mississippi field cores ranging from 10 to 54 years old. These protocols, beam and elevated curing, were able to replicate what was seen for pavement cores that were extracted after decades of service. Over 1300 specimens were testing showing how these mechanical properties interacted from early ages and throughout a pavement’s life.

Rammed earth is a technique of forming in-situ structural wall elements using rigid formwork. Advantages of rammed earth walls include flexibility in plan form, scope for adjusting strength and wall thickness, variety of textural finishes, lower embodied carbon and energy, etc. There is a growing interest in the construction of rammed earth buildings in the recent past. Well focused comprehensive studies in understanding the structural performance of rammed earth structures are scanty. Clear-cut guidelines on selecting soil grading and soil characteristics, assessing strength of rammed earth walls, density strength relationships, limits on shrinkage, standardised testing procedures, behaviour of rammed earth walls under in-plane and out of plane loads, etc are the areas needing attention. The thesis attempts to address some of these aspects of cement stabilized rammed earth for structural walls. Brief history and developments in rammed earth construction with illustrations of rammed earth buildings are presented. A review of the literature on rammed earth has been provided under two categories: (a) Unstabilised or pure rammed earth and (b) stabilised rammed earth. Review of the existing codes of practice on rammed earth has also been included. Summary of the literature on rammed earth along with points requiring attention for further R&D are discussed. Objectives and scope of the thesis are listed. The thesis deals with an extensive experimentation on cement stabilised rammed earth (CSRE) specimens and walls. Four varieties of specimens (cylindrical, prisms, wallettes and full scale walls) were used in the experiments. A natural soil and its reconstituted variants were used in the experimental work. Details of the experimental programme, characteristics of raw materials used in the experimental investigations, methods of preparing different types of specimens and their testing procedures are discussed in detail. Influence of soil grading, cement content, moulding water content, density and delayed compaction on compaction characteristics and strength of cement stabilised soil mixes were examined. Five different soil gradings with clay content ranging between 9 and 31.6% and three cement contents (5%, 8% and 12%) were considered. Effect of delayed compaction (time lag) on compaction characteristics and compressive strength of cement stabilised soils was examined by monitoring the results up to 10 hours of time lag. Influence of moulding water content and density on compressive strength and water absorption of cement stabilised soils was examined considering for a range of densities and water contents. The results indicate that (a) there is a considerable difference between dry and wet compressive strength of CSRE prisms, and the strength decreases as the moisture content at the time of testing increases, (b) wet strength is less than that of dry strength and the ratio between wet to dry strength depends upon the clay fraction of soil mix and cement content, (c) saturated moisture content depends upon the cement content and the clay content of the soil mix, (d) optimum clay percentage yielding maximum compressive strength is about 16%, (e) compressive strength of compacted cement stabilised soil increases with increase in density irrespective of cement content and moulding moisture content, and the strength increases by 300% for 20% increase in density from 15.70 kN/m3, (f) compressive strength of rammed earth is one - third higher than that of rammed earth brick masonry and (g) density decreases with increase in time lag and there is 50% decrease in strength with 10 hour time lag. Stress-strain relationships and elastic properties of cement stabilised rammed earth are essential for the analysis of CSRE structural elements and understanding the structural behaviour of CSRE walls. Influence of soil composition, density, cement content and moisture on stress-strain relationships of CSRE was studied. Three different densities (15.7 – 19.62 kN/m3) and three cement percentages (5%, 8% and 12% by weight) were considered for CSRE. Stress-strain characteristics of CSRE and rammed earth brick masonry were compared. The results reveal that (a) in dry condition the post peak response shows considerable deformation (strain hardening type behaviour) beyond the peak stress and ultimate strain values at failure (dry state) are as high as 3.5%, which is unusual for brittle materials, (b) modulus for CSRE increases with increase in density as well as cement content and there is 1 to 3 times increase as the cement content changes from 5% to 12%. Similarly the modulus increases by 2.5 to 5 times as the dry density increases from 15.7 to 19.62 kN/m3 and (c) the modulus of CSRE and masonry in dry state are nearly equal, whereas in wet state masonry has 20% less modulus. Compressive strength and behavior of storey height CSRE walls subjected to concentric compression was studied. The results of the wall strength were compared with those of wallette and prism strengths. The wall strength decreases with increase in slenderness ratio. There is nearly 30% reduction in strength as the height to thickness ratio increases from 4.65 to 19.74. It was attempted to calculate the ultimate compressive strength of CSRE walls using the tangent modulus theory. At higher slenderness ratios, there is a close agreement between the experimental and predicted values. The storey height walls show lateral deflections as the load approaches failure. The walls did not show visible buckling and the shear failure patterns indicate material failure. The shear failures noticed in the storey height walls resemble the shear failures of short height wallette specimens. The thesis ends with a summary of the results with concluding remarks in the last chapter.

Made available in DSpace on 2014-12-17T14:06:57Z (GMT). No. of bitstreams: 1 SheylaKJM_DISSERT.pdf: 2022444 bytes, checksum: 199284d45ddc8db628d0e2f45da9a7e8 (MD5) Previous issue date: 2011-01-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present work is to study the characteristics and technological properties of soil-cement bricks made from binary and ternary mixtures of Portland cement, sand, water, with or without addition of gravel from the drilling of oil wells, which could be used by industry, aiming to improve its performance and reduce cost by using the residue and, consequently, increasing its useful life. The soil-cement bricks are one of the alternatives to masonry construction. These elements, after a short curing period, provide compressive strength similar to that of solid bricks and ceramic blocks, and the higher the resistance the higher the amount of cement used. We used the soil from the city of S?o Jos? do Mipibu / RN, the banks of the River Baldun, cement CPIIZ-32 and residue of drill cuttings from oil wells drilling onshore wells in the town of Mossley, RN, provided Petrobras. To determine the optimum mix, we studied the inclusion of different residues (100%, 80%, 70%, 60% and 50%) where 15 bodies were made of the test piece. The assessment was made of bricks made from simple compression tests, mass loss by immersion and water absorption. The experimental results proved the efficiency and high utilization of the waste from the drilling of oil wells, making the brick-cement-soil residue with a higher strength and lower water absorption. The best result in terms of mechanical strength and water absorption for the ternary mixture was 10% soil, 14% cement and 80% residue. In terms of binary mixtures, we obtained the best result for the mix-cement residue, which was 14% cement incorporated in the residue / O presente trabalho consiste no estudo das caracter?sticas e propriedades tecnol?gicas de tijolos solo-cimento formulados a partir de misturas bin?rias e tern?rias de cimento Portland, areia, ?gua, com e sem adi??o de cascalho proveniente da perfura??o de po?os de petr?leo, que poder?o ser utilizados pela ind?stria, com o objetivo de melhorar seu desempenho e diminuir seu custo utilizando o res?duo e, conseq?entemente, aumentando sua vida ?til. Os tijolos de solo-cimento constituem uma das alternativas para a constru??o em alvenaria. Esses elementos, ap?s pequeno per?odo de cura, garantem resist?ncia ? compress?o simples similar ? dos tijolos maci?os e blocos cer?micos, sendo a resist?ncia tanto mais elevada quanto maior for ? quantidade de cimento empregada. Foi utilizado o solo proveniente do Munic?pio de S?o Jos? do Mipib?/RN, as margens do Rio Baldun, cimento CPIIZ-32 e res?duo de cascalho de perfura??o de po?os de petr?leo proveniente da perfura??o de po?os Onshore, no munic?pio de Mossor?/RN, fornecido pela Petrobras. Para a determina??o da mistura ?tima, estudou-se a inclus?o de teores de res?duos diferenciados (100%; 80%; 70%; 60% e 50%) onde foram confeccionados 15 corpos-de-prova. A avalia??o dos tijolos confeccionados foi feita a partir de ensaios de compress?o simples, perda de massa por imers?o e absor??o de ?gua. Os resultados experimentais comprovaram a efici?ncia e o elevado potencial de utiliza??o do res?duo proveniente da perfura??o de po?os de petr?leo, tornando o tijolo de solo-cimento-res?duo com uma maior resist?ncia mec?nica e menor absor??o de ?gua. O melhor resultado, em termos de resist?ncia mec?nica e absor??o d ?gua, para a mistura tern?ria, foi de 10% de solo, 14% de cimento e 80% de res?duo. Em termos de misturas bin?rias, obteve-se o melhor resultado para a combina??o cimento-res?duo, que foi de 14% de cimento incorporado no res?duo

Made available in DSpace on 2016-06-02T20:00:47Z (GMT). No. of bitstreams: 1 4872.pdf: 3473885 bytes, checksum: 1bd5a5d73dae0ecc0bb5b60b52acba6b (MD5) Previous issue date: 2012-11-27 / In view of the lack of basic infrastructure in Brazilian cities, especially in regard to paving networks, it is of fundamental importance a study to ascertain the geological characteristics of the materials available and their potential use as pavement layer after incorporation of additives. This thesis aims at determining, in the laboratory, the mechanical results of soiladditive mixture, in order to evaluate the structural performance of chemically stabilized tropical soils. It also brings, specific objectives, comparing traditional additives - cement and lime - with another additive available in the brazilian market; analyzing the possibility of using these stabilized soils in urban pavement layers and obtaining reference results that may provide subsidies for pavement designers. This research develops from the collection of four (4) soil samples at different points in São Carlos/SP, with whom has been conducted a series of tests: California Bearing Ratio, Expansion and Compression Test. There was an evaluation of soils by determining the mechanical properties of the mixed soil and additive, in terms of carrying capacity, simple compression and expansion. The results were obtained after compression of the mixture in the test specimens and the use of standardized testing methodologies. After a long series of laboratory tests developed for each sample, a critical analysis of structural performance, primarily in its natural condition, then with the structural behavior of each of them, after the incorporation of additives. Research has shown that the best structural behavior of all samples collected in the different conditions of stabilization occurred with the sample ST-03 which, stabilized with 6% cement, obtained in laboratory satisfactory performance for use as the base layer of pavement. / Em vista da carência de infra-estrutura básica nas cidades brasileiras, principalmente no que se refere às redes de pavimentação, faz-se de fundamental importância um estudo que permita conhecer as características geológicas dos materiais disponíveis e as suas possibilidades de utilização como camada de pavimento após a incorporação de aditivos. Esta dissertação tem como objetivo principal determinar, em laboratório, os resultados mecânicos da mistura soloaditivo, a fim de se avaliar o desempenho estrutural de solos tropicais estabilizados quimicamente. Traz ainda, como objetivos específicos, comparar os aditivos tradicionais - cimento e cal - com uma opção de aditivo disponível no mercado brasileiro; analisar a possibilidade de utilização desses solos estabilizados em camadas de pavimentos urbanos e obter resultados de referência que venham a fornecer subsídios aos projetistas de pavimento. Esta pesquisa desenvolve-se a partir da coleta de 4 (quatro) amostras de solo em diferentes pontos do município de São Carlos/S.P., com as quais se realizou uma série de ensaios de Capacidade de Suporte (CBR), Expansão (EXP.) e de Resistência a Compressão Simples (RC). Fez-se a avaliação dos solos tropicais através da determinação das propriedades mecânicas das misturas de solo e aditivo, em termos de capacidade de suporte, expansão e compressão simples. Os resultados foram obtidos após a compactação da mistura, em corpos de prova e com o emprego das metodologias de ensaio normalizadas. Após uma larga série de ensaios de laboratório, desenvolveu-se, para cada amostra, uma análise crítica do desempenho estrutural, primeiramente, em sua condição natural e, depois, no comportamento estrutural de cada uma delas, após a incorporação dos aditivos supracitados. A pesquisa demostrou que o melhor comportamento estrutural de todas as amostras coletadas, nas diversas condições de estabilização, ocorreu com a amostra ST-03 que, estabilizada com 6% de cimento, obteve em laboratório desempenho satisfatório para emprego como camada de base de pavimento.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-06-20T21:53:08Z No. of bitstreams: 1 FRANCISCO AUGUSTO DE SOUZA - TESE PPGEP 2011.pdf: 49177196 bytes, checksum: 3a3bd80203819d1ca322cf48f20425fa (MD5) / Made available in DSpace on 2018-06-20T21:53:08Z (GMT). No. of bitstreams: 1 FRANCISCO AUGUSTO DE SOUZA - TESE PPGEP 2011.pdf: 49177196 bytes, checksum: 3a3bd80203819d1ca322cf48f20425fa (MD5) Previous issue date: 2011-08-22 / 0 acelerado processo de modernização na agroindústria tem contribuído para o aumento significativo na geração de resíduos agrícolas que acarretam danos para o meio ambiente. O processo de beneficiamento do arroz gera grande quantidade de casca, estes resíduos são, geralmente, depositados em terrenos ou lançados em cursos d'água, ocasionando degradações ambientais, devido à lenta biodegradação. O seu aproveitamento na construção civil, como produto alternativo, pode contribuir para a conservação e a preservação do meio ambiente. Este trabalho tem por objetivo o estudo da durabilidade de blocos de solo-cimento com a incorporação de casca de arroz. Os ensaios foram realizados com auxílio de ciclos de molhagem e secagem, para avaliar a durabilidade dos blocos convencionais e alternativos incorporados com casca de arroz. Os resultados obtidos indicam que o aumento do teor de casca de arroz, eleva o valor de absorção de água, diminui a resistência à compressão simples, aumenta a perda de massa e a variação de volume, devido o grande volume de vazios apresentados pela casca de arroz e a falta de interação entre o sistema solo-cimento e casca de arroz. Os ensaios de durabilidade pelo método de degradação acelerada e os ensaios de caracterização mineralógica realizados com os blocos alternativos de solo-cimento incorporados com casca de arroz indicaram a composição de 10% de cimento mais a combinação de 86% solo e 4% de casca de arroz, ideal para a fabricação de blocos de alvenaria para construção civil. / The accelerated process of modernization in the agricultural industry has contributed to the signrficant increase in the generation of agricultural residues that cause damage to the environment. The beneficiation process generates large quantities of rice husk, these wastes are usually deposited on land or thrown into streams, causing environmental degradation due to slow bíodegradation. Its use in construction, such as alternative product, can contribute to the conservation and preservation of the environment. This work aims to study the durability of soil-cement with the addition of rice husk. The tests were carried out usíng cycles of wettíng and drying, to evaluate the durability of conventional and alternative blocks embedded with rice husk. The results indicate that increasing the amount of rice husk, raises the value of water absorption, decreases the compressive strength, increases the loss of mass and volume change, due to the large volume of voids produced by rice husk and lack of interaction between the soil-cement and rice husk. Durability testing by the method of accelerated degradation and mineralogical characterization tests performed with the alternative blocks of soil-cement íncorporated with rice husk indicated the composítion of 10% cement plus the combination of soil and 4% 86% peei rice, ideal for the manufacture of masonry blocks for construction.

The Industrial Revolution generated two parallel phenomena during the twentieth century: increased distribution of wealth and reduced energy costs, causing a large increase in energy consumption. With the international oil crisis in the 1970s, materials used until that time such as concrete, steel and glass, began to be seen as energy-intensive materials. Society began to seek buildings with minimal environmental impact, using materials that generate a smaller amount of energy, waste and pollution and CO2 emissions in the atmosphere and provide greater potential for reincorporation into nature. In this scenario, raw soil as a building material has become an alternative for the development of sustainable buildings, but also to improve the livability of housing for the low-income population in the country. Among various construction materials, raw soil-cement, which is cured without burning, is raw soil pressed and stabilized with Portland cement, which is already regulated by the Brazilian Technical Standards Association (ABNT) and possesses many advantages related to its manufacturing and use. To increase its acceptance and verify its efficiency as a building material for social housing, it is necessary to investigate its properties and performance. Thus, the present study aimed to evaluate the performance of an external vertical sealing system composed of soil-cement blocks without structural function for social housing, following determinations of NBR 15575 (2013), focusing on the requirements of Habitability and Sustainability. The habitability require the heat action and thermal shock test. Firstly, using the particle size analysis and liquid limit and plastic limit test, to characterize the compostion of the ground on which the block was used. The bodies-of-proof were tested in The laboratory of Structural Models and Tests (Laboratório de Ensaios e Modelos Estruturais LEME), at the Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, and consisted of two full scale walls. The system met limits set by standards for tightness against rainwater and heat action and thermal shock, but not for permeability to water. The vertical sealing system composed of hollow blocks of soil-cement has great potential for application in the construction of social housing, but there is still a need for more studies on the system. / A Revolução Industrial gerou, durante o século XX, dois fenômenos paralelos: a maior distribuição de riqueza e a diminuição do custo de energia, causando um grande aumento no consumo energético. Com a crise internacional do petróleo, na década de 1970, os materiais utilizados, até então, como concreto, aço e vidro, passam a ser vistos como materiais de grande consumo energético. A sociedade começa a buscar edificações com menor impacto ambiental possível, que utilizem materiais que envolvam baixo consumo energético, baixa geração de resíduos e poluentes, baixa emissão de CO2 na atmosfera e grande potencial de reincorporação na natureza. Diante desse cenário, a terra crua como material construtivo se torna uma alternativa para o desenvolvimento de edificações sustentáveis, como também, para a melhoria da habitabilidade das moradias da população de baixa renda existente no país. Das diversas técnicas de construção com a terra crua, o solo-cimento é um material curado sem queima, composto de terra crua prensada e estabilizada com cimento Portland, que já é normatizado pela Associação Brasileira de Normas Técnicas (ABNT), possuindo muitas vantagens que vão desde a fabricação até sua utilização no canteiro de obras. Para melhor aceitação e comprovação da sua eficiência como material construtivo para habitações de interesse social, é necessário que se conheça suas propriedades e seu desempenho. Dessa forma, a presente pesquisa consistiu em avaliar o desempenho de um sistema de vedação vertical externo composto por blocos de solo-cimento sem função estrutural para habitações de interesse social térreas, seguindo determinações da NBR 15575 (ABNT, 2013), focando nas exigências de Habitabilidade e Sustentabilidade. Como exigência de Habitabilidade analisou-se o fator Estanqueidade, com a realização dos ensaios de Estanqueidade à Água da Chuva e Permeabilidade à Água. E, como exigência de Sustentabilidade analisou-se os fatores Durabilidade e Manutenibilidade, com a realização do ensaio de Ação de Calor e Choque Térmico. Primeiramente, através de ensaio de análise granulométrica, limite de liquidez e limite de plasticidade, foi caracterizado o solo do qual o bloco utilizado é composto. Os corpos-de-prova foram ensaiados no Laboratório de Ensaios e Modelos Estruturais (LEME), da Universidade Federal do Rio Grande do Sul (UFRGS), em Porto Alegre, RS, e consistiram em duas paredes em escala real. O sistema atendeu aos limites estabelecidos pela norma nos ensaios de Estanqueidade à Água da Chuva e Ação de Calor e Choque Térmico, o que não ocorreu no ensaio de Permeabilidade à Água, no qual o sistema não atendeu às exigências. Através dos resultados dos ensaios verificou-se que o sistema de vedação vertical composto por blocos vazados de solo-cimento possui grande potencial para aplicação na construção, principalmente de habitações de interesse social, mas ainda há a necessidade de mais estudos sobre o sistema.

CAPES / Neste trabalho buscou-se avaliar o cone de penetração dinâmica (DCP) como alternativa para controle geotécnico em vias urbanas de tráfego leve. Atualmente, dentre os diversos ensaios disponíveis para avaliação do comportamento mecânico dos solos, destaca-se o uso do CBR, porém, este possui desvantagem quanto à demora para obtenção de seus resultados, devido ao procedimento intrínseco do ensaio. Sob esta perspectiva, o presente trabalho se propõe a analisar a utilização do DCP como uma alternativa mais econômica, viável, segura e vantajosa para o controle geotécnico das camadas componentes das vias. A área de estudo encontra-se na cidade de Curitiba, no Estado do Paraná, Brasil. O estudo foi realizado através de investigações de campo e ensaios laboratoriais, para obtenção da correspondência entre a penetração do cone de penetração dinâmica no solo e o ensaio CBR. Além disso, foi realizada a avaliação do comportamento do DCP com a variação de umidade e com o grau de compactação. Ademais, foram realizadas correlações entre o CBR e a Agulha de Proctor e também comparações entre os solos do subleito (sem cimento) e o solo da base das vias (com cimento) em diferentes idades, também com o uso o DCP. Os resultados se mostraram positivos quanto à viabilidade de uso do DCP para estimativa de controle de compactação, de capacidade de suporte dos solos e também quanto à facilidade de manuseio tanto em laboratório quanto em campo. / This study aims to evaluate the dynamic cone penetration (DCP) as methodology for geotechnical control on urban roads of light traffic. Currently, among the various tests available to evaluate the mechanical behavior of the soil, there is the use of CBR, however, this has disadvantages as the long time for obtaining the results, due to the intrinsic test procedure. From this perspective, the present study aims to analyze the use of DCP equipment - Dynamic Cone Penetration - as a more economical alternative, feasible and safe for the analysis of the compression levels of the component layers of the urban roads. The study area is located in the city of Curitiba, State of Parana, Brazil. The study is conducted through field and laboratory tests of the local soil to obtain mathematical correlations to ensure correspondence between the cone penetration and the CBR in situ. In addition, the evaluation of the performance of the equipment with the moisture content variation and degree of compaction was carried out. In addition, correlations were made between the CBR and the Proctor penetrometer and also comparisons between the soils of the subgrade (without cement) and base course of the roads (with cement) at different ages, also with the use of DCP. The results were positive regarding the feasibility of using the equipment to estimate compaction control, soil load bearing capacity and also for ease of handling both in the laboratory and in the field.

Rammed earth is a monolithic construction formed by compacting processed soil in progressive layers. Rammed earth is used for the construction of load bearing walls, floors, sub base material in roadways, airport runways, taxiways, aprons, foundations and earthen bunds. Soil, sand, cement and water are the ingredients used for the preparation of cement stabilized rammed earth (CSRE) specimens. The cracking in a rammed earth structure is due to the development of tensile stresses. The tensile stresses are generated due to various causes like unequal settlement of foundation, eccentric loading and / or lateral loading such as wind pressure and earthquake on an earth structure. The cracking in a rammed earth structure causes the failure of its intended function. For example formation of crack may lead to the instability of an embankment slope. And earthen dam can be destroyed gradually by erosion of soil at the crack surface (Harison et al. 1994). Hence, it becomes important to understand the fracture behaviour of cement-stabilized rammed earth structures. Well focused studies in understanding the fracture behaviour of CSRE structures are scanty. The present work attempts to address some issues on the fracture behaviour of CSRE including size effect. Through an experimental programme material properties viz. compressive strength, tensile strength and stress-strain relationships are generated for two chosen densities, 17 and 18.5 kN/m3 of CSRE both in dry and saturated condition. Soil composition, density, cement content and moisture content of the specimen during testing influence the characteristics of CSRE. In the present investigation keeping the cement at 10%, the density is varied choosing a soil-sand mixture having optimum grading limits. The basic raw materials used are soil, sand, cement and water in the ratio of 1 : 1.5 : 0.25 : 0.34 by weight. The strength properties studied alone are inadequate to predict the mechanics of fracture due to the presence of microscopic flaws, cracks, voids and other discontinuities. Therefore, some linear elastic fracture parameters such as mode I fracture toughness (KIc), critical energy release rate (GIc), net section strength (f net) and notch sensitivity are calculated, presuming that CSRE is still a brittle material because it is yet to be confirmed that CSRE is a quasibrittle material. In fact, in the present work, it is shown that CSRE has significant amount of softening. A comprehensive experimental work has been undertaken to test CSRE beam specimens for two densities, three sizes of beam and three notch to depth ratios under three point bending (TPB) in a closed loop servo-controlled machine with crack mouth opening displacement control. Results indicate that the CSRE in dry condition exhibits a greater resistance to fracture than the saturated specimen. The variation of net section strength with the notch depth is not significant. Therefore the CSRE material is notch insensitive, implying that it is less brittle. An experimental program was undertaken to determine the nonlinear fracture parameters of beam specimens both in dry and saturated condition. The influence of moisture content, density, size of the specimen as well as notch to depth ratio of the specimen on RILEM fracture energy (G F ) are presented. The GF values increase with increase in density and size of the specimen, while they decrease with increase in notch to depth ratio. Results clearly show that the total energy absorbed by the beams (W OF ) and RILEM fracture energy (G F ) for all specimens tested in dry state are higher compared to the specimens tested in saturated state, indicating that the dry specimen offers higher resistance to the crack propagation. The RILEM fracture energy GF , determined from TPB tests, is said to be size dependent. The assumption made in the work of fracture is that the total strain energy is utilized for the fracture of the specimen. The fracture energy is proportional to the size of the fracture process zone (FPZ), which also implies that size of FPZ increases with increase in the un-cracked ligament (d - a) of beam. This also means that FPZ is proportional to the depth d for a given notch to depth ratio, because for a given notch/depth, (d - a) which is also is proportional to d because is a constant. This corroborates the fact that fracture energy increases with size. Interestingly, the same conclusion has been drawn by Karihaloo et al. (2006). They have plotted a curve relating fracture process zone length and overall depth the beam. In the present study a new method namely Fracture energy release rate method proposed by Muralidhara et al. (2013) is used. In the new method the plot of GF /(d - a) versus (d - a) is obtained from a set of experimental results. The plot is found to follow power law and showed almost constant value of GF /(d - a) at larger ligament lengths. This means the fracture energy reaches a constant value at large ligament lengths reaffirming that the fracture energy from very large specimen is size-independent. This Fracture energy release rate method is used to determine size-independent fracture energy GRf , based on the relationship between RILEM fracture energy and the un-cracked ligament length. The experimental results from the present work agree well with the proposed new method. Similarly, the method is extended to determine nominal shear strength τv for large size beam. Results show that for both densities GRf decrease in saturated condition, while in dry condition as the density is increased from 17 to 18.5 kN/m3 the GRf decrease by 7.58%, indicating that the brittleness increases with higher density. The τv for large size beam increases with density both in dry and saturated condition. The size effect method for evaluating material fracture properties proposed by Bazant (1984) is applied to cement stabilised rammed earth. By measuring the peak loads of 2D geometrically similar notched beam specimens of different sizes, nonlinear fracture parameters such as fracture energy (Gf ), fracture toughness (KIc), effective length of the fracture process zone (Cf ), brittleness number (β), characteristic length (l 0) and the critical crack tip opening displacement (CT ODc) are determined for both dry and saturated conditions. The crack growth resistance curves (R-curve) are also developed for dry and saturated specimens. In the size effect method, for both densities 18.5 and 17 kN/m3 the values of nonlinear fracture properties, namely G f , Cf , KIc, CT ODc and l 0 are lower for the saturated specimen compared to those of the dry specimen. In dry condition as the density is increased from 17 to 18.5 kN/m3 the Gf decreases to 13.54%, indicating that the brittleness increase with higher density. The areas under the load-displacement and load-CMOD curves are a measure of the fracture energy and these areas are low for saturated specimens. The crack growth resistance curves (R-curve) plotted using the size-effect law from peak loads are the measure of resistance against crack growth R. The value of R is high for dry specimen compared to that of the saturated specimens. During aggregate pullout or the opening of crack, the interlock or friction between the crack surfaces may cause the energy dissipation through friction and bridging across the crack. Therefore the wet friction in case of saturated specimen must be smaller resulting in more brittleness compared to the larger dry friction for dry specimen. In the present investigation the Digital Image Correlation (DIC) technique is used to study the FPZ properties in cement stabilised rammed earth. The MATLAB package written by Eberl et al. (2006) is suitably modified and used for image correlation to suit our requirements. CMOD measured using DIC technique is validated by comparison with the CMOD measured using clip gauge. The FPZ properties such as the development of FPZ and crack opening displacements at different loading points as well as the influence of notch/depth ratio on FPZ length (lFPZ ) are evaluated for both dry and saturated conditions. At peak load the lFPZ are about 0.315 and 0.137 times the un-cracked ligament length respectively for specimens tested under dry and saturated conditions. In dry and saturated states the FPZ length decreases as the ratio increases. Lower values of lFPZ in saturated specimen indicates that it is relatively more brittle compared to dry specimen.