<p>The thesis is dealing with mixing processes havingapplication to ground improvement by deep mixing. The mainobjectives of the thesis is to make a contribution to knowledgeof the basic mechanisms in mixing binding agents into soil andimprove the knowledge concerning factors that influence theuniformity of stabilised soil.</p><p>A great part of the work consists of a literature surveywith particular emphasis on literature on the processindustries. This review forms a basis for a profounddescription and discussion of the mixing process and factorsaffecting the process in connection with deep mixingmethods.</p><p>The thesis presents a method for a simple field test for thestudy of influential factors in the mixing process. A number offactors in the installation process of lime-cement columns havebeen studied in two field tests using statistical multifactorexperiment design. The effects of retrieval rate, number ofmixing blades, rotation speed, air pressure in the storagetank, and diameter of the binder outlet on the stabilisationeffect and the coefficient of variation determined byhand-operated penetrometer tests for excavated lime-cementcolumns, were studied.</p><p>The literature review, the description of the mixingprocess, and the results from the field tests provide a morebalanced picture of the mixing process and are expected to beuseful in connection to ground improvement projects and thedevelopment of mixing equipments.</p><p>The concept of sufficient mixture quality, i.e. theinteraction between the mixing process and the mechanicalsystem, is discussed in the last section. By means ofgeostatistical methods, the analysis considers thevolume-variability relationship with reference to strengthproperties. According to the analysis, the design values forstrength properties depends on the mechanical system, the scaleof scrutiny, the spatial correlation structure, and the conceptof safety, i.e. the concept of sufficient mixture quality isproblem specific.</p><p><b>Key words:</b>Deep Mixing, Lime cement columns, Mixingmechanisms, Mixture quality, Field test, ANOVA, Variancereduction.</p>

Lime softening, chlorination, clarification and filtration have been long recognized treatment processes for beverage water specifically the carbonated soft drink (CSD) because it provides consistent water quality required for bottling plants, however these processes are becoming uneconomical and causes more problems than the benefits they offer. These processes require very large foot print, occupy large plant volume, and generate large volume of sludge which causes disposal problems. Chlorination produces trihalomethanes (THMs) and other by-products which are detrimental to health and imparts tastes to the final products. Using the newly developed submerged spiral wound ultrafiltration membranes in conjunction with lime softening may replace the conventional lime softening, clarification and filtration processes. This research was conducted to demonstrate the feasibility of integrating immersed ultrafiltration (UF) membrane with lime softening. The objectives of this research was to achieve the water quality required by the CSD bottlers; determine the relationships of operating parameters such as pH and membrane flux with trans-membrane pressure (TMP), and membrane permeability; determine the optimum dosage of lime; evaluate the operating parameters as basis for the design and construction of the full scale plant; and predict the membrane cleaning intervals. A pilot unit consisting of lime reactor and UF system was designed and built for this research. The pilot unit was operated at various pH ranging from 7.3 to 11.2 and at membrane flux rates of 15, 30 and 45 gfd. The pilot unit was also operated at the CSD bottler’s operating conditions which is pH 9.8 at flux of 30 gfd. The pilot unit operated for a total of 1800 hours. The raw water source was from city water supply. The filtrate from the pilot unit achieved alkalinity reduction to 20 to 30 mg/L preferred by CSD bottlers, with lime dosage close to the calculated value. The filtrate turbidity during the test was consistently within 0.4 to 0.5 NTU. The TMP values obtained during the test ranges from 0.1 to 2.5 psi, while the permeability values ranges from 18.19 to 29.6 gfd/psi. The increase in flux results to corresponding increase in TMP, and increase in operating pH, increases the rate of TMP. Permeability decreases with increasing operating pH. The TOC reduction ranges from 2.6 % to 15.8% with increasing operating pH. No scaling of the UF membranes was observed during the test. Thirty days UF membrane cleaning interval was predicted. The results from this research can use as the basis of designing and operating a full scale Lime Softening UF Treatment Plant.

Syftet med arbetet är att beskriva ett antal olika metoder som används vid viktning i samband med livscykelanalyser, samt diskutera hur valet av metod kan påverka resultatet av analysen. Metoderna som beskrivs är EPS2000, Ecoindicator99, ReCiPe, Stepwise2006 och LIME. Varje metod beskrivs kort med påverkanskategorier, skyddsobjekt och indikatorer. Metoderna grundas på beräkningar av utsläpp och resursanvändning, men för att få fram viktningstalen så använder man sig av olika teorier, paneldiskussioner, frågeformulär och subjektiva antagande. Min slutsats är att det är svårt att få viktningsmetodiken mindre subjektiv, och att mycket vid viktningen bygger på antagande. Varje metod bygger på olika antaganden och det är därför viktigt att man är tydlig med vilka omständigheter som gäller vid beräkningarna samt att man inte jämför resultat från olika metoder. Däremot så går det utmärkt att jämföra olika produkter med hjälp av samma viktningsmetod, och att hitta i vilket skede i livscykeln som man får störst miljöpåverkan. Jag tror att det egentligen är diskussionen kring produktens miljöpåverkan som är det väsentliga, inte värdena som man får från viktningen, då dessa till så stor del baseras på antagande och gissningar. / The purpose of the study is to describe some methods used for weighting when conducting a life cycle analysis, and discuss how the choice of method may effect the result of the analysis. The methods described are EPS2000, Ecoindicator99, ReCiPe, Stepwise2006 and LIME. Each method is shortly described with impact categories, safety objects and indicators. The methods are based upon calculations of pollutions and use of resources, but to get the weightingfactors, one will have to rely on different theories, panel discussions, questionnaries and subjective assumptions. The conclusion of the study will be that it is difficult to get the methods for weighting less subjective, and that much of the weighting will be based upon assumptions. Every method is built on different assumptions, and therefor is it important that each are clear with the circumstances for the calculations, and you can not compare results from the different methods. On the contrary you may compare products if you use the same one for both, and you may also find in which phase of the lifecycle when you will get the most impact of the environment. I think that the discussion about the environmental impact of the product is most important, not the figures you will get from the procedure of weighting, which is based upon assumptions and guesses.

Abstract available in PDF copy. / Thesis (M.Sc.-Chemical Engineering)-University of Natal, 1988.

The thesis is dealing with mixing processes havingapplication to ground improvement by deep mixing. The mainobjectives of the thesis is to make a contribution to knowledgeof the basic mechanisms in mixing binding agents into soil andimprove the knowledge concerning factors that influence theuniformity of stabilised soil. A great part of the work consists of a literature surveywith particular emphasis on literature on the processindustries. This review forms a basis for a profounddescription and discussion of the mixing process and factorsaffecting the process in connection with deep mixingmethods. The thesis presents a method for a simple field test for thestudy of influential factors in the mixing process. A number offactors in the installation process of lime-cement columns havebeen studied in two field tests using statistical multifactorexperiment design. The effects of retrieval rate, number ofmixing blades, rotation speed, air pressure in the storagetank, and diameter of the binder outlet on the stabilisationeffect and the coefficient of variation determined byhand-operated penetrometer tests for excavated lime-cementcolumns, were studied. The literature review, the description of the mixingprocess, and the results from the field tests provide a morebalanced picture of the mixing process and are expected to beuseful in connection to ground improvement projects and thedevelopment of mixing equipments. The concept of sufficient mixture quality, i.e. theinteraction between the mixing process and the mechanicalsystem, is discussed in the last section. By means ofgeostatistical methods, the analysis considers thevolume-variability relationship with reference to strengthproperties. According to the analysis, the design values forstrength properties depends on the mechanical system, the scaleof scrutiny, the spatial correlation structure, and the conceptof safety, i.e. the concept of sufficient mixture quality isproblem specific. Key words:Deep Mixing, Lime cement columns, Mixingmechanisms, Mixture quality, Field test, ANOVA, Variancereduction.

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-19Bitstream added on 2014-06-13T21:05:22Z : No. of bitstreams: 1 missio_rl_dr_jabo.pdf: 805386 bytes, checksum: fd72382d10b76ace86d683f99af93f1d (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este estudo objetivou avaliar o armazenamento da cana-de-açúcar hidrolisada com 0,5% de cal hidratada sobre o consumo das frações alimentares, desempenho animal, viabilidade econômica, comportamento ingestivo, características nutritivas da forragem e aspectos da digestão de novilhas confinadas. Foram realizados dois experimentos. No primeiro (Capítulo 2 e 3), foram utilizadas 24 novilhas da raça Nelore distribuídas inteiramente ao acaso nos tratamentos formados por dietas com cana-de-açúcar in natura (tempo zero), cana-de-açúcar hidrolisada e armazenada por 24, 48 ou 72 horas. No segundo (Capítulo 4), foram utilizadas quatro novilhas da raça Nelore delineadas num quadrado latino 4x4, onde foram avaliadas as dietas anteriormente descritas. No primeiro experimento, verificou-se variação cúbica (P < 0,05) em função do tempo de armazenamento da cana-de-açúcar da maioria das variáveis relacionadas ao consumo das frações alimentares e desempenho animal, apresentando melhores resultados para novilhas alimentadas com cana-de-açúcar in natura. O armazenamento da cana-de-açúcar até 72 horas proporcionou aumento linear (P < 0,05) da fração de carboidratos potencialmente degradáveis e diminuição dos custos de produção. Novilhas alimentadas com dietas a base de cana-de-açúcar in natura apresentaram maior tempo de ruminação (P < 0,05). No segundo experimento, verificou-se que o consumo e digestibilidade dos nutrientes, o balanço de nitrogênio, a eficiência de síntese de proteína microbiana e o nitrogênio amoniacal não foram influenciados (P > 0,05) pelas dietas. O armazenamento da cana-de-açúcar com adição de 0,5% de cal hidratada até 72 horas deprime o consumo e desempenho de novilhas jovens da raça Nelore / This study evaluated the effect of storage of hydrolyzed sugarcane with .5% hydrated lime the dietary fractions intake, animal performance, economic viability, ingestive behavior, nutritional characteristics of forage and digestion aspects of confined heifers. Two experiments were conducted. In the first (Chapter 2 and 3), 24 Nellore heifers were used and randomly distributed in treatment formed by diets constituted by fresh sugarcane (zero time), hydrolyzed sugarcane and stored for 24, 48 or 72 hours. In the second (Chapter 4), four heifers were used constituting a 4x4 latin square, with similar diets previous. In the first experiment, there was variation cubic (P < .05) according the storage time of most variables related to dietary fractions intake and animal performance, with better results for heifers fed with fresh sugarcane. Storage of sugarcane until 72 hours promoted linear increased (P < .05) in the carbohydrate fraction potentially degradable and decreased production costs. Heifers fed diets with fresh sugarcane presented higher time ruminating (P < .05). In the second experiment, it was found that the intake and digestibility of nutrients, the nitrogen balance, the efficiency of microbial protein synthesis and the ammonia nitrogen were not affected (P > .05) by diets. The storage of hydrolyzed sugarcane with .5% of hydrated lime up to 72 hours depresses intake and performance of young Nellore heifers

A capacidade de manter a estabilidade e integridade durante o tempo de exposição às forças destrutivas do intemperismo é um dos aspectos mais importantes da estabilização de solos em projetos de pavimentos. Esta dissertação apresenta resultados de um estudo laboratorial sobre o comportamento mecânico de um solo dispersivo estabilizado com cal. O solo estudado é um solo sedimentar de sedimentos quaternários pertencente à denominada região ocidental do Paraguai. O solo dispersivo se caracteriza por apresentar teores significativos de sódio e por apresentar erosão hídrica acelerada. O objetivo deste estudo foi avaliar a durabilidade de misturas de Solo-Cal submetidos a ciclos de molhagem e secagem. A resistência à compressão simples e resistência à vácuo saturação também foram examinadas para avaliar o desempenho de misturas de Solo-Cal. Medição da velocidade de pulso de ultra-som foi realizado como teste não destrutivo para monitorizar a rigidez das misturas. Os efeitos do tempo de cura, das características de compactação e do teor de cal, foram avaliados. Finalmente, desde um enfoque ambiental através da ferramenta de avaliação do ciclo de vida (ACV) foram avaliadas todas as misturas em função aos impactos ambientais potenciais gerados na construção de 1 m³ de subbase de Solo-Cal. Verificou-se que a durabilidade, a rigidez e a resistência de solos estabilizados com cal aumentam com o tempo de cura, com a energia de compactação e com o aumento do teor de cal. Além disso, a dispersibilidade intermediaria (ND4) que o solo apresentava em seu estado natural, muda para não dispersivo (ND1) com a adição de 2% de cal. Em conclusão ressalta-se que a mistura SC3-5 apresenta um melhor comportamento mecânico comparável com a mistura SC3-7, mas, com um menor impacto potencial gerado. / The ability to retain stability and integrity during the exposure time to the destructive forces of weathering is one of the most important aspects of soil stabilization in pavements design. This thesis presents the results of a laboratory study of the mechanical behavior of a dispersive soil stabilized with lime. The studied soil is a sedimentary soil of the quaternary sediments belonging to the so called western region of Paraguay. The dispersive soil is characterized by having significant levels of sodium and accelerated erosion. The objective of this study was to evaluate the durability of soil-lime mixtures subjected to wetting and drying cycles. Resistance to simple compression and resistance to vacuum saturation were also examined to assess the performance of soil-lime mixtures. Measurement of the ultrasonic pulse velocity was performed as non-destructive testing for monitoring the stiffness of the blends. The effects of curing time, the compression characteristics and lime content, were evaluated. Finally, all mixtures were evaluated from an environmental viewpoint by the life cycle assessment (LCA). All mixtures were evaluated according to the environmental impact in the construction of 1 m³ of Soil-Lime. It was found that durability, rigidity and resistance of soil stabilized with lime increases with cure time, with the energy of compaction and with increased lime content. Moreover, the dispersibility intermediate (ND4) showed that the soil in its natural state, changes to nondispersive (ND1) with the addition of 2% lime. In conclusion it is emphasized that the SC3-5 mixture has a better mechanical behavior comparable to SC3-7 mix, but with less potential impact generated.

A presente pesquisa apresenta uma análise laboratorial da adesividade e do comportamento mecânico de concretos asfálticos elaborados com agregados de granito e com ligante convencional (CAP 50/70) e ligante modificado por polímero (AMP CAP 60/85), priorizando os efeitos decorrentes da incorporação de dois tipos de cales. A primeira, denominada cal calcítica (com elevado teor de óxido de cálcio) é oriunda do Estado de Minas Gerais e, a segunda, denominada cal dolomítica, produzida no Estado do Rio Grande do Sul. Para a dosagem das seis misturas estudadas foi utilizada a metodologia Marshall, sendo posteriormente realizados ensaios de Resistência à Tração por Compressão Diametral, Módulo de Resiliência, Dano por Umidade Induzida (AASHTO T 283/89) e Resistência à Fadiga utilizando-se o ensaio de Tração indireta por compressão diametral, no modo tensão controlada. De posse dos resultados laboratoriais foi realizada uma análise elástico - linear, utilizando o Programa Computacional EVERSTRESS 5.0, e aplicado os resultados de deformação nos modelos obtidos em laboratório para as seis misturas analisadas. Considerando este critério, pode-se observar que os melhores resultados foram obtidos para as misturas elaboradas com ligante modificado. Quando empregado o ligante convencional evidenciou-se a melhora do comportamento da resistência à Fadiga das misturas que tiveram incorporação de cal (aumento de até 330% quando empregada cal calcítica e de até 348% quando empregada cal dolomítica), enquanto que quando preparadas com ligante modificado por polímero, a mistura que apresentou melhores resultados foi a elaborada sem incorporação de cal. Outro fato constatado e importante diz respeito a interação entre a cal, o ligante e o agregado granítico, já que diferentemente do esperado, a incorporação de cales não ocasionou resultados satisfatórios na adesividade. / This research shows a laboratory test of adhesiveness and the mechanical behavior of asphalt concrete prepared with granitic aggregate and conventional binder (CAP 50/70) and polymer-modified binder (AMP CAP 60/85), prioritizing the effects resulting from the merger of two types of limes. The first, called calcite lime (with high content of calcium oxide), comes from the Brazilian State of Minas Gerais; the second, the dolomitic lime, is produced in the State of Rio Grande do Sul. The Marshall method assessed the six mixtures studied; subsequently, Tensile Strength for Diametral Compression, Resilience Module, Damage Induced by Humidity (AASHTO T 283/89) and Resistance to Fatigue were tested by means of indirect traction by diametrical compression in controlled stress mode. A linear elastic analysis followed the laboratory results, using Computational Program EVERSTRESS 5.0; deformation results obtained in laboratory models for the six analyzed mixtures were applied. In accordance with this criterion, the best results point to asphalt mixtures prepared with modified binder. The use of conventional binder showed improvement in the fatigue resistance behavior of mixtures that take lime incorporation (increase of up to 330% with calcite lime, and up to 348% with dolomitic lime); however, when prepared with polymer-modified binder, the mixture that showed the best results did not have the addition of lime. Another noteworthy fact confirmed concerns the interaction amongst the lime, the binder and the granitic aggregate: unlike expected, the incorporation of limes did not convey satisfactory results in adhesiveness.

Varieties of masonry units such as burnt clay bricks, stones and concrete products are used for masonry construction. Even though these materials are durable, they are considered as unsustainable options because of the issues concerning energy, environment and conservation of natural resources. The walling materials are consumed in bulk quantities and hence large quantities of natural resources are depleted. There is a need for energy efficient and environment friendly alternative materials for masonry. Fly ash is an industrial by-product from the coal based thermal power plants which can be exploited for manufacturing of masonry units such as fly ash blocks/bricks, which are an alternative for conventional masonry units. Fly ash-Lime-Gypsum (FaL-G) bricks can be manufactured by compaction of a mixture of fly ash-lime-gypsum and water. The behaviour of FaL-G brick masonry is inadequately explored area and hence the thesis is focused on understanding the flexural behaviour of FaL-G brick masonry and bond development phenomenon at FaL-G brick-mortar interface. A brief introduction to the fly ash-based masonry units and literature review with respect to utilizing fly ash in manufacturing masonry units are presented. Characteristics of raw materials used and the procedure followed in casting of masonry units/compacts, mortar and their assemblages including testing methods have been discussed. Characteristics of FaL-G brick, mortars, FaL-G brick masonry are presented. Apart from determining the stress-strain relationships for these materials shear strength parameters of FaL-G compact, mortar and brick-mortar joint were determined. Mohr-Coulomb failure envelopes for FaL-G compact and mortar are presented. The mechanism of bond development in masonry is discussed. FaL-G brick masonry shows considerably higher bond strength when compared with the bond strength of conventional brick masonry. Results of micro-structure analysis (SEM, XRD and TGA) of the FaL-G brick-mortar interfaces confirm the formation of chemical bond in addition to mechanical interlocking of cement hydration products into brick pores. Flexural behaviour of FaL-G brick masonry wallettes in the two orthogonal directions was studied. The flexural strength, displacement profiles and load-displacement curves were determined, and moment-curvature relationships were established. Linear elastic analysis performed closely predicted the cracking flexural stress in FaL-G brick masonry. A brief introduction to the computational modelling of masonry using different approaches has been presented. Literature review with respect to simplified micro-modelling approach has been discussed. The flexural behaviour of FaL-G brick masonry panels under lateral loads was predicted using a non-linear 3D finite element analysis. The finite element model reasonably predicted the flexural behaviour of FaL-G brick masonry panels. The thesis ends with summary of research work with a note on scope for further research.