O solo é base de praticamente todas as obras de Engenharia Civil e em algumas cituaçoes não apresenta condições de suportar o carregamento imposto, tal problema pode ser solucionado com técnicas de estabilização. A estabilização com cal é uma técnica clássica porem não apresenta um método racional de dosagem. Entretanto este quadro vem alterando-se por meio de pesquisas que buscam utilizar o coeficiente porosidade/teor volumétrico de cal para dosar solo-cal. Assim, esta pesquisa tem como objetivo avaliar a influencia do coeficiente /(Liv) na variação de resistência à compressão simples e à tração na compressão diametral de misturas solo- cinza volante-cal para diferentes temperaturas, devido a natureza endotérmica das reações de hidratação da cal. Para isso foram realizados ensaios de compressão simples e de tração por compressão diametral em corpos de prova com 3, 5 e 7 % de cal (em peso), com pesoespecifica aparente seca de 14, 15 e 16 kN/m², curados a 20, 27, 35 e 50ºC por 28 dias e com 25% de cinza volante. Os resultados encontrados demonstram que ambas as resistências estudadas aumentam linearmente com o aumento da quantidade de cal e exponencialmente com a redução da porosidade. A relação porosidade/teor volumétrico de cal ajustado por um coeficiente [/(Liv)0,3] mostrou-se adequada na previsão da resistência a tração e compressão para todas as temperaturas estudadas. A temperatura mostrou ter grande influência em ambas as resistências estudadas, sendo que até uma dada temperatura, representada por 35°C para tração e 27°C para compressão, a relação [ ( ) ] com a temperatura é linear, após esta temperatura torna-se uma assíntota. A razão entre a resistência a tração e a compressão foi de 0,18, 0,14, 0,20 e 0,19 para as temperaturas de 20, 27, 35 e 50°C, respectivamente. / Soil is the base of most civil engineering constructions, and when it cannot support the construction loads, such problem can be solved through the use of soil stabilization technique. Lime stabilization is a classical technique, but there are still no dosage methods of these mixtures based on more rational criteria. This situation has been changed with researches using the porosity/lime ratio to dose soil-lime. Thereby this research aims to evaluate the influence of the quotient /(Liv) in the assessment of splitting tensile and unconfined compressive strength at different temperatures, due to the endothermic nature of the reactions of lime hydration. For this research splitting tensile tests and unconfined compression tests were carried out with cylindrical specimens with diameter and height equal to 50 and 100mm, respectively, with lime contents varying from 3% to 7%, dry unit weight ranging from 14kN/m³ to 16kN/m³, time curing period of 28 days and fly ash content of 25%. The results show the unconfined compressive and the splitting tensile strength increasing linearly with the increase of lime amount and exponentially with the reduction of its porosity. The porosity/lime ratio, defined as the ratio of the compacted mixture porosity and the lime volumetric content, adjusted by an exponent, proves to be an appropriate parameter to estimate the unconfined compressive and the splitting tensile strength of the soil-fly ash-lime studied. The temperature has influence in both resistances studied. For a given curing time period, the relation [ ( ) ] versus T is shown to vary linearly up to a threshold, 35°C for the splitting tensile strength and 27°C for the unconfined compressive strength, when becomes an asymptote. Finally, the qt/qu relationship is not unique for the mixture studied, being 0,18, 0,14, 0,20 e 0,19 for the temperatures 20, 27, 35 e 50°C, respectively.

The doctoral thesis deals with the reactivity of burnt clays in connection with modified lime mortars. The theoretical part of the doctoral thesis provides an overview of the properties of lime mortars, their quality and ways of their degradation. The different types of burnt clays (brick powder, bentonites and burnt clay shale), their origin, properties and factors affecting their reactivity and methods of its evaluation are stated. The properties and reactivity of burnt clays are evaluated on the basis of determination of pozzolanic activity, mineralogical and chemical composition, surface area, density, content of the amorphous phase and granulometry in the experimental part of the doctoral thesis. The compositions of lime mortars containing burnt clays and evaluation of an impact of burnt clay on the properties of mortars in the fresh and hardened state are given. Consistency, bulk density, workability and air content of mortars in the fresh state are evaluated. Strength characteristics depending on the time, water absorbability, porosity, capillary attraction, adhesion, coefficient of diffusion resistance, frost resistance, shrinkage, mineralogical composition and microstructure of mortars in the hardened state are evaluated. Attention is also paid to the influence of the cellulose ether addition into the modified lime mortars.

An investigation was made of the properties and utility or the lime slurry from the acetylene generators of the E. I. DuPont de Nemours Co. plant at Waynesboro, Virginia in seeking methods for its disposal. The slurry was found to run from 7% to 17% in solids, which settle rapidly, and the solids to contain 88% calcium hydroxide. It was found impractical to dispose of the slurry by draining in lime ponds for farm haulage, by drying with flue gases or by dumping it in the nearby South River. It was found feasible to dry the slurry for agricultural uses by adding burnt lime and to prepare insecticides such as lime-sulfur and calcium arsenate, the market for which materials was found extensive in the region. / M.S.

Under den andra stenbyggnadsperioden på Gotland började bönderna på landsbygden att bygga sina hus utav sten. De hade egna stenbrott där de kunde bryta både byggnadssten och sten till kalkbränning. Stenen brände de i milor eller husbehovsugnar. Även ekonomibyggnaderna uppfördes i sten på Gotland, detta är unikt i ett svenskt och nordiskt sammanhang. Murbruksprover från tio ekonomibyggnader har samlats in, alla gårdarna belägna i det stora kalkstensbältet på norra Gotland. Området är intressant att studera eftersom kalkbruksindustrin växte sig så stor här. En okulär besiktning av murbruksproverna i fält har genomförts, där provets kulör noterats och murbrukets innehåll av exempelvis sand och kalkklumpar med mera beskrivits. Det har tillverkats tunnslip av murbruksproverna för att på djupet kunna analysera dess innehåll och sammansättning. Genom analyserna kan vi spåra hur kalkbrukstraditionerna sett ut ute på landsbygden och vilka lokala traditioner som finns. Resultatet visar att stenen från Lärbroområdet har varierande kvalitet och egenskaper, där både ren och mer eller mindre oren sten bränts och nyttjats i kalkputs och kalkfärg. Stenen har gett ett kalkbruk med vissa orenheter i kalkpastan och inslag av ballastbildande hydrauliska korn, som inte gett bruket andra egenskaper än att det kan räknas som ett luftkalkbruk. Denna kalken är karakteristisk för gården i Vägume, där även en svagt hydraulisk kalk har dokumenterats. Denna har man dock behövt torrsläcka för att kunna göra bruk av den. En grynig luftkalk i vissa fall med inslag av hydrauliska ballastkorn ses också i bruksproverna från Hägvide i Lärbro, Stora Ire i Hellvi och vid Lunderhage i Fleringe där även ren kalkpasta använts. Gotland är känd för sin rena feta luftkalk, så som kan ses i proverna från Risungs i Rute, Gaustäde i Bunge och på Fårö. Det är därför intressant att se att svagt hydraulisk sten använts på Gotland och att de som haft tillgången till denna stenen lärt sig använda den. Hydraulisk kalk fanns även i ett av bruksproverna från Angelbos, denna var starkt hydraulisk och skulle kunna vara ett KC-bruk, eftersom de hydrauliska partiklarna näst intill är glasartade så som klinker. Blandningsförhållandet ligger generellt på 1:2 men även magrare och kalkrikare bruksblandningar förekommer i de undersökta proverna. Proverna är förhållandevis kompakta. I Rute och Bunge har man blandat fetare bruk, de flesta bruksproverna visar ett blandningsförhållande omkring 1:1, vissa något magrare. I Bunge påträffades troligen ett medeltida bruk, det var mycket kalkrikt, innehöll lite sand och många kalkklumpar som delvis bildade ballast. Fetare än 1:1. Det är en kalk som lagrats över länger tid och kan mycket väl ha jordsläckts. Denna traditionen ser vi inte i de andra bruksproverna där kalken släckts och använts direkt. Ballasten i näst intill samtliga bruksprover är mycket finkornig, omkring 0,5 mm och mindre. Inslag av större sandkorn förekommer med även dessa är små. Kalkklumparnas storlek varierar mycket från mm stora korn till 1 cm. De största mellan 2 – 3 cm. Ett modernare inslag och förhållningssätt till bruksblandning påträffades vid Risungs i Rute. Här har luftporbildare tillsatts vilket resulterat i ett bruk med ett kollapsat porsystem som ger dålig beständighet. Kontrasten är stor jämfört med de äldre feta och kompakta 1:1 bruken från Risungs.  Två av proverna innehöll större mängd lera. I provet från Vägume kommer lerinnehållet troligen från sanden som i delar av området är rik på lera, det är det enda provet som kan räknas som ett lerblandat kalkbruk i studien. Detta visar att även sanden kan skilja rätt mycket lokalt inom ett litet område som i sin tur ger bruk med olika egenskaper. I provet från Hägvide ses inslag av tegelröda partiklar som kommer av lerlager i den brända kalkstenen. Den tegelröda kulören kommer av att leran innehåller järnmineraler. I spritputsen har enbart kalk och naturgrus nyttjats, vilket är något ovanligt eftersom det gärna tillsätts lite sand även i spritputs. Det skulle kunna bero på att kalken i sig bidrar med ballast i form av kalkklumpar som gjort att sanden setts på som onödig. En regional variant som setts i flera av de analyserade bruksproverna. Studien visar att lokala material använts under den andra stenbyggnadsperioden på Gotland och att stenförekomsten har lokala variationer i och mellan socknarna, vilket gör att lokala traditioner kan utskiljas. Sanden är i större utsträckning av samma typ i de undersökta områdena, medans det i Vägume nyttjats både lerblandad sand och ren finkornig sand. Blandningsförhållandet generellt är omkring 1:2 vilket överensstämmer det nationala förhållningssättet som kom utöver 1700-talet. Så sätt skiljer sig Risungs och Gaustäde ut där traditionen för något fetare kalkbruk levt kvar. Vägumes lokala tradition där svagt hydraulisk kalk och grynig kalk med inslag av hydrauliska partiklar använts är därför intressant. / During the second stone building period on Gotland, the farmers in the countryside began to build their houses out of stone. They had their own quarries where they could mine both building stone and stone for lime burning. They burned the stone in lime kilns or household furnaces. The agricultural buildings were also built in stone on Gotland, this is unique in a Swedish and Nordic context. Mortar samples from ten agricultural buildings have been collected, they are all located in the large limestone belt in northern Gotland. This area is interesting to study because of the expansion in the lime industry here. An ocular inspection of the mortar samples was carried out during the field studies, where the colour of the sample was noted as well as the mortars content of, for example sand and lime lumps etc. Thin sections were made from the mortar samples in order to be able to analyse its content and composition. Through analysis we gained knowledge about the lime mortar traditions in the countryside and their local traditions.   The results shows that the stone from the Lärbro area has varying quality and properties, where both clean and more or less impure stone was burned and used in lime render and lime wash. The stone has given us a lime mortar with certain impurities in lime paste and elements of hydraulic grains forming aggregate. This type of lime is characteristic for the studied area in Vägume, where a sub hydraulic lime also where documented. The sub hydraulic one would have to be dry slaked in order to use it in mortar. A grainy lime in some cases with elements of hydraulic grains is also seen in the mortar samples from Hägvide in Lärbro, Stora Ire in Hellvi and at Lunderhage in Fleringe where pure lime paste also were used. Gotland is known for its pure and lime rich slime, as can be seen in the samples from Risungs in Rute, Gaustäde I Bunge and at Fårö. Its therefore interesting to see that sub hydraulic lime has been used on Gotland. Hydraulic lime was also found in one of the samples from Angelbos, where the amount of hydraulic binder was high, it could in fact be a KC-mortar, the hydraulic particles remind of clinker. The mixing ratio is generally 1:2, although leaner and more lime rich mortars occur in the examined samples. The mortars are relatively compact. In Runte and Bunge, the lime mortars appear to be fatter, most of the samples show a mixing ratio of around 1:1, some slightly leaner. In Bunge, a medieval mortar was probably found. It was extremely lime rich, containing little sand and many lumps of lime which partly formed aggregate. Fatter than 1:1. The lime that’s been used in this mortar has been stored for a long time and were probably earth slaked. We do not see this tradition in the other mortar samples where the lime was slaked and used directly. The aggregate in almost all of the mortars is very fine-grained sand, with a grain size around 0,5 mm and smaller. Elements of larger sand grains occur. The size of the lime limps varies greatly from mm-sized grains to 1 cm. The largest between 2-3 cm.  A more modern element and approach to traditional lime mortar was found in one of the samples from Risungs in Rute, where air entraining agent has been added. Resulting in a mortar with a collapsed pore system that gives the mortar poor durability. The contrast I great compared to the older lime rich and compact 1:1 mortars from Risungs.  Another interesting result showed that two of the samples contained larger amounts of clay. In the sample from Vägume the sand itself contained clay, which can be seen in parts of the area. This is the only clay-mixed lime mortar in the study. This shows that even the sand can differ quite a lot within a small area, which in turn produces mortars with different properties. In the sample from Hägvide, elements of brick-red particles can be seen in the thin section. This comes from layers of clay in the burnt lime stone. The brick-red colour comes from a clay containing iron minerals.  In the type of lime render that creates a granulated surface, only lime and see gravel have been used, which is somewhat unusual because a little amount of sand is often added. Maybe the sand was seen as unnecessary because the lime itself contributes with aggregate through the lime lumps. A regional variant seen in several of the analysed mortar samples.   The study shows that local materials were used during the second stone building period on Gotland, and that the stone that’s been used has local variations within and between the parishes, which means that local traditions can be distinguished. The sand is to a greater extent of the same type in the investigated areas, while in Vägume both clay-mixed sand and pure fine-grained sand were used. The mixing ratio is generally around 1:2, which corresponds to the national approach that came beyond the 18th century. This is how Risungs and Gaustäde stands out, where the tradition of somewhat fatter lime mortar has survived. Vägumes local tradition where sub hydraulic lime and gritty lime with elements of hydraulic particles were used is therefore interesting.

Thesis (M.A. in Cultural Resources Management)--Sonoma State University, 2005. / Includes bibliographical references (p. 112-127) and abstract.

Cada vez mais freqüente a utilização de técnicas tradicionais da engenharia geotécnica depara-se com obstáculos de caráter econômico e ambiental. A técnica do solo-cal torna-se atrativa quando o melhoramento das propriedades do solo do local constitui-se numa alternativa de projeto. A técnica de tratamento de solos com cal encontra aplicação, por exemplo, na construção de bases para pavimentos, na proteção de taludes em barragens de terra e como camada de suporte para fundações superficiais. Entretanto, ainda não existem metodologias de dosagem e projeto das misturas de solo-cal baseadas em critérios racionais como existe no caso do concreto, onde a relação água/cimento desempenha papel fundamental na obtenção da resistência desejada. Nesse sentido, este estudo tem por objetivo quantificar a influência da quantidade de cal, da porosidade e do teor de umidade de moldagem, sobre a resistência de um solo arenoso tratado com cal e rocha basáltica pulverizada, avaliar a adequação do uso das relações água/cal e vazios/cal na estimativa da sua resistência à compressão simples e comparar as variáveis envolvidas com amostras tratadas com cimento em iguais proporções. Para isso foram realizados ensaios de compressão simples e medidas de sucção matricial. Os resultados mostram que a resistência à compressão simples cresceu linearmente com o aumento da quantidade de cal e exponencialmente com a redução na porosidade da mistura compactada. Além disso, a variação do teor de umidade de moldagem não afetou consideravelmente a resistência à compressão simples em misturas compactadas numa mesma massa específica aparente seca. Verificou-se que, para o solo-cal no estado nãosaturado (estado em que normalmente se encontram os aterros compactados), a relação água/cal não é um bom parâmetro para estimativa da resistência à compressão simples. Ao contrário, a relação vazios/cal, assim como a relação vazios/cimento, definido pela razão entre a porosidade da mistura compactada e o teor volumétrico de aglomerante, ajustado por um expoente, demonstraram ser o parâmetro mais adequado na estimativa da resistência à compressão simples do solo-cal e do solo-cimento estudado. / Not rarely, the use of traditional techniques in geotechnical engineering faces obstacles of economical and environmental nature. The soil-lime technique becomes attractive when the improvement of the local soil is a project alternative. The treatment of soils with lime finds application, for instance, in the construction of pavement base layers, in slope protection of earth dams and as a support layer for shallow foundations. However, there are no dosage methodologies and design based on rational criteria as it exists in the case of concrete technology, where the water/cement ratio plays a fundamental role in the assessment of the target strength. In that sense, this study aims to quantify the influence of lime amount, the porosity and the moisture content on the strength of a sandy soil treated with lime and pulverized basaltic rock, as well as to evaluate the use of a water/lime ratio and a voids/lime ratio to assess its unconfined compression strength and to compare the evaluated variables with samples treated by cement in the same proportions. A number of unconfined compression tests and measures of matric suction were carried out. The results show that the unconfined compression strength increased linearly with the increase of the lime amount and exponentially with the reduction on the porosity of the compacted mixture. Besides, the change on the moisture content doesn’t remarkably affected the unconfined compression strength of mixtures compacted in the same dry density. It was verified that, for the soil-lime in the unsaturated state (state usually met in compacted fills), the water/lime ratio is not a good parameter for assessment of unconfined compression strength. In the other hand, the voids/lime ratio, as well as the voids/cement ratio, defined by the reason between the porosity of the compacted mixture and the volumetric binder content, adjusted by an exponent, demonstrated to be the most appropriate parameter in the estimate of unconfined compression strength of the studied soil-lime and soil-cement.

Cada vez mais freqüente a utilização de técnicas tradicionais da engenharia geotécnica depara-se com obstáculos de caráter econômico e ambiental. A técnica do solo-cal torna-se atrativa quando o melhoramento das propriedades do solo do local constitui-se numa alternativa de projeto. A técnica de tratamento de solos com cal encontra aplicação, por exemplo, na construção de bases para pavimentos, na proteção de taludes em barragens de terra e como camada de suporte para fundações superficiais. Entretanto, ainda não existem metodologias de dosagem e projeto das misturas de solo-cal baseadas em critérios racionais como existe no caso do concreto, onde a relação água/cimento desempenha papel fundamental na obtenção da resistência desejada. Nesse sentido, este estudo tem por objetivo quantificar a influência da quantidade de cal, da porosidade e do teor de umidade de moldagem, sobre a resistência de um solo arenoso tratado com cal e rocha basáltica pulverizada, avaliar a adequação do uso das relações água/cal e vazios/cal na estimativa da sua resistência à compressão simples e comparar as variáveis envolvidas com amostras tratadas com cimento em iguais proporções. Para isso foram realizados ensaios de compressão simples e medidas de sucção matricial. Os resultados mostram que a resistência à compressão simples cresceu linearmente com o aumento da quantidade de cal e exponencialmente com a redução na porosidade da mistura compactada. Além disso, a variação do teor de umidade de moldagem não afetou consideravelmente a resistência à compressão simples em misturas compactadas numa mesma massa específica aparente seca. Verificou-se que, para o solo-cal no estado nãosaturado (estado em que normalmente se encontram os aterros compactados), a relação água/cal não é um bom parâmetro para estimativa da resistência à compressão simples. Ao contrário, a relação vazios/cal, assim como a relação vazios/cimento, definido pela razão entre a porosidade da mistura compactada e o teor volumétrico de aglomerante, ajustado por um expoente, demonstraram ser o parâmetro mais adequado na estimativa da resistência à compressão simples do solo-cal e do solo-cimento estudado. / Not rarely, the use of traditional techniques in geotechnical engineering faces obstacles of economical and environmental nature. The soil-lime technique becomes attractive when the improvement of the local soil is a project alternative. The treatment of soils with lime finds application, for instance, in the construction of pavement base layers, in slope protection of earth dams and as a support layer for shallow foundations. However, there are no dosage methodologies and design based on rational criteria as it exists in the case of concrete technology, where the water/cement ratio plays a fundamental role in the assessment of the target strength. In that sense, this study aims to quantify the influence of lime amount, the porosity and the moisture content on the strength of a sandy soil treated with lime and pulverized basaltic rock, as well as to evaluate the use of a water/lime ratio and a voids/lime ratio to assess its unconfined compression strength and to compare the evaluated variables with samples treated by cement in the same proportions. A number of unconfined compression tests and measures of matric suction were carried out. The results show that the unconfined compression strength increased linearly with the increase of the lime amount and exponentially with the reduction on the porosity of the compacted mixture. Besides, the change on the moisture content doesn’t remarkably affected the unconfined compression strength of mixtures compacted in the same dry density. It was verified that, for the soil-lime in the unsaturated state (state usually met in compacted fills), the water/lime ratio is not a good parameter for assessment of unconfined compression strength. In the other hand, the voids/lime ratio, as well as the voids/cement ratio, defined by the reason between the porosity of the compacted mixture and the volumetric binder content, adjusted by an exponent, demonstrated to be the most appropriate parameter in the estimate of unconfined compression strength of the studied soil-lime and soil-cement.

The product of the hydration process of lime, milk of lime, is a byproduct of lime commonly used industrially because it is present in the industrial processes of steel mill, chemical and sugar and alcohol. But the hydration process has been little studied and this dissertation aims to study the influence of the hydration process in the quality of product and the influence of quality of milk of lime in the efficiency of the industrial process which milk of lime is used. Through industry data found that the hydration process current and more useful for industrial is inappropriate and produces high amounts of residues that provide the company losses. In the industrial process the quality of milk of lime improves the performance of the industrial process by reducing the amount of material used and the amount of residue formed, consequently its accumulation in the equipment. And to produce a lime milk of good quality, high surface area and low amount of residue, you should use a mixing process suitable for the suspensions of lime milk with low particle sizes of lime and heating of initial water of hydration. And especially an efficient and appropriate agitation Therefore, the pilot of a unit of hydration was proposed and through this became the rheological behavior of suspensions of milk of lime and with these data, made up the study of power consumed by the agitator. It was also proposed changes on impeller to improve the efficiency of agitation and a system of residue removal at the end of hydration through rotary screens. / O produto proveniente do processo de hidratação da cal, o leite de cal, é um dos subprodutos da cal mais utilizados industrialmente, pois está presente nos processos das indústrias siderúrgicas, químicas e usinas de açúcar e álcool. Porém o processo de hidratação ainda é pouco estudado e esta dissertação tem como objetivo estudar a influência do processo de hidratação da cal na qualidade do produto e a influência da qualidade do leite de cal na eficiência do processo industrial no qual a leite de cal é utilizado. Através de dados industriais verificou-se que o processo de hidratação atual e mais usaado pelas industriais é inadequado e produz quantidades altas de resíduos, proporcionando a empresa perdas. No processo industrial a qualidade do leite de cal melhora o desempenho do processo industrial diminuindo a quantidade de material utilizado e a quantidade de resíduos formados, conseqüentemente o seu acúmulo nos equipamentos. E para se produzir um leite de cal de boa qualidade, com alta área superficial e baixa quantidade de resíduos, deve-se utilizar um processo de mistura adequado as suspensões de leite de cal: Granulometrias baixas de cal e aquecimento da água inicial de hidratação. E principalmente uma agitação eficiente e adequada. Por isso, o projeto piloto de uma unidade de hidratação foi proposto e através deste fez-se o estudo reológico das suspensões de leite de cal e com esses dados, fez-se o estudo da potência consumida pelo agitador. Também foi proposto mudanças no agitador para melhorar a eficiência da agitação e um sistema de remoção de resíduos ao final da hidratação através de peneiras rotativas. / Mestre em Engenharia Química

Cada vez mais freqüente a utilização de técnicas tradicionais da engenharia geotécnica depara-se com obstáculos de caráter econômico e ambiental. A técnica do solo-cal torna-se atrativa quando o melhoramento das propriedades do solo do local constitui-se numa alternativa de projeto. A técnica de tratamento de solos com cal encontra aplicação, por exemplo, na construção de bases para pavimentos, na proteção de taludes em barragens de terra e como camada de suporte para fundações superficiais. Entretanto, ainda não existem metodologias de dosagem e projeto das misturas de solo-cal baseadas em critérios racionais como existe no caso do concreto, onde a relação água/cimento desempenha papel fundamental na obtenção da resistência desejada. Nesse sentido, este estudo tem por objetivo quantificar a influência da quantidade de cal, da porosidade e do teor de umidade de moldagem, sobre a resistência de um solo arenoso tratado com cal e rocha basáltica pulverizada, avaliar a adequação do uso das relações água/cal e vazios/cal na estimativa da sua resistência à compressão simples e comparar as variáveis envolvidas com amostras tratadas com cimento em iguais proporções. Para isso foram realizados ensaios de compressão simples e medidas de sucção matricial. Os resultados mostram que a resistência à compressão simples cresceu linearmente com o aumento da quantidade de cal e exponencialmente com a redução na porosidade da mistura compactada. Além disso, a variação do teor de umidade de moldagem não afetou consideravelmente a resistência à compressão simples em misturas compactadas numa mesma massa específica aparente seca. Verificou-se que, para o solo-cal no estado nãosaturado (estado em que normalmente se encontram os aterros compactados), a relação água/cal não é um bom parâmetro para estimativa da resistência à compressão simples. Ao contrário, a relação vazios/cal, assim como a relação vazios/cimento, definido pela razão entre a porosidade da mistura compactada e o teor volumétrico de aglomerante, ajustado por um expoente, demonstraram ser o parâmetro mais adequado na estimativa da resistência à compressão simples do solo-cal e do solo-cimento estudado. / Not rarely, the use of traditional techniques in geotechnical engineering faces obstacles of economical and environmental nature. The soil-lime technique becomes attractive when the improvement of the local soil is a project alternative. The treatment of soils with lime finds application, for instance, in the construction of pavement base layers, in slope protection of earth dams and as a support layer for shallow foundations. However, there are no dosage methodologies and design based on rational criteria as it exists in the case of concrete technology, where the water/cement ratio plays a fundamental role in the assessment of the target strength. In that sense, this study aims to quantify the influence of lime amount, the porosity and the moisture content on the strength of a sandy soil treated with lime and pulverized basaltic rock, as well as to evaluate the use of a water/lime ratio and a voids/lime ratio to assess its unconfined compression strength and to compare the evaluated variables with samples treated by cement in the same proportions. A number of unconfined compression tests and measures of matric suction were carried out. The results show that the unconfined compression strength increased linearly with the increase of the lime amount and exponentially with the reduction on the porosity of the compacted mixture. Besides, the change on the moisture content doesn’t remarkably affected the unconfined compression strength of mixtures compacted in the same dry density. It was verified that, for the soil-lime in the unsaturated state (state usually met in compacted fills), the water/lime ratio is not a good parameter for assessment of unconfined compression strength. In the other hand, the voids/lime ratio, as well as the voids/cement ratio, defined by the reason between the porosity of the compacted mixture and the volumetric binder content, adjusted by an exponent, demonstrated to be the most appropriate parameter in the estimate of unconfined compression strength of the studied soil-lime and soil-cement.

Die heiße Verarbeitung von Kalk ist eine sehr spezielle Technik, die nur noch von wenigen Handwerkern und Restauratoren, überwiegend in Deutschland und Großbritannien, angewandt wird. In der Literatur lässt sich die Heißkalktechnik seit dem Beginn der Renaissance nachweisen, frühere Beiträge erscheinen vage, aus römischer Zeit liegen keine Belege vor. Seit Beginn der Neuzeit gab es jedoch immer wieder Ansätze, Kalk für Mörtel oder Anstriche heiß zu verarbeiten. Mit Beginn des 20. Jahrhunderts verschwinden Einträge in der Literatur, erst im 21. Jahrhundert wird wieder von ersten Erfahrungen berichtet. Beim Kalklöschen wird Wärme frei, welche dazu führt, dass sich die Mischung aus Branntkalk, Löschkalk und Wasser sehr stark erhitzt. Heißkalk bedeutet dementsprechend, dass aus diesem löschenden Kalk ein Mörtel oder eine Tünche hergestellt und diese sofort verarbeitet wird. Diese Technik führt zu besonderen Eigenschaften der Mischung, die durch die übliche Art und Weise Kalk zu verarbeiten, nicht zu erreichen wären. Von den Praktikern werden ein frühes Ansteifen, eine höhere Festigkeit, eine bessere Haftung, bessere feuchtetechnische Eigenschaften sowie eine bessere Salzresistenz beschrieben. Dies konnte mit naturwissenschaftlichen Methoden, die jedoch oftmals speziell für Unter-suchungen dieses außergewöhnlichen Materials angepasst werden mussten, belegt werden. Das frühe Ansteifen und die Ausbildung einer höheren Festigkeit hängen nicht mit einer hydraulischen Aktivierung der Zuschläge zusammen, wie es von den Praktikern vermutet wurde, sondern mit der Mikrostruktur im Gefüge, welches in der Frühphase entsteht. Durch das schnelle Löschen bildet sich zunächst ein Gerüst aus prismatischen Portlanditen aus, welches sich dann, im Verlauf der Carbonatisierung, in ein Gefüge aus grobkristallin verzahnten Calcitskalenoeder umwandelt. Gerade für ein früheres Ansteifen ist die prismatische Portlanditbildung, einhergehend mit einem Wasserentzug durch die Löschreaktion, von besonderer Bedeutung. Das Bindemittelgefüge aus grobkristallin verzahnten Calcitskalenoedern und das Mörtelgefüge mit einem verzweigten Schwundrisssystem werden für die guten feuchtetechnischen Eigenschaften und die gute Salzresistenz verantwortlich gemacht. Diese Merkmale lassen die Heißkalkmörtel für besondere Anforderungen in der Denkmalpflege und Restaurierung geeignet erscheinen. Dort, wo es auf ein schnelles Ansteifen ankommt, beispielsweise beim Aufmauern von unebenen Feldsteinen, bei der Kronensicherung von Ruinen, beim Auswerfen von großen Hohlräumen oder Fugen, kann mit Heißkalk ein zügigerer Bauablauf gewährleistet werden. Durch die gute Haftung, die höhere Festigkeit, die guten Feuchtetransporteigenschaften und die Salzresistenz erscheinen Heißkalkmörtel geeignet, fallweise dort eingesetzt zu werden, wo üblicherweise hydraulische Systeme auf Zement- oder Trassbasis verwendet würden, beispielsweise für Sockelverputze auf salz- und feuchtebelastetem Mauerwerk. Es lassen sich demnach in speziellen Fällen anspruchsvolle Aufgaben in reiner Kalktechnik lösen, ohne Alkalieneintrag oder Überfestigung durch hydraulische Zusätze. Heißkalktünchen zeichnen sich durch eine höhere Schichtstärke im Vergleich mit Sumpfkalktünchen aus. Sie sind in der Haftung am Untergrund überlegen und lassen sich gut verarbeiten. Dadurch sind sie für schnelldeckende großflächige Anstriche geeignet. Ein weiterer Vorteil, sowohl von Heißkalkmörteln als auch –tünchen, liegt in der schnellen Verfügbarkeit. Da keine langen Einsumpfzeiten zu berücksichtigen sind oder nicht trocken vorgelöscht werden muss, kann, je nach Bedarf, in kleinen Mengen aus demselben Pulverbranntkalk ein Mörtel oder eine Tünche angemischt und sofort verarbeitet werden. Aufgrund der hohen Temperaturen, es werden bis zu 80°C erreicht, und der hohen Alkalinität der Mischungen, welche besondere Anforderungen an den Arbeitsschutz stellen, wird Heißkalk nur dort eingesetzt werden, wo andere Kalktechniken nicht zufriedenstellende Ergebnisse erzielen. Dadurch erweitert die Heißkalktechnik jedoch die Einsatzmöglichkeiten des historischen Baustoffs Kalk. / Hot applied mortar (HAM) is a historic technique which is in use just of some craftsmen and restorers, mainly in Germany and Great Britain. Literal searches show that hot lime has been used repeatedly since the Renaissance. An earlier use, especially in Roman times, could not be proven. The properties postulated by the practitioners, such as early stiffening, higher strength, better moisture-technical properties, and better resistance to salt could be demonstrated. However, a higher strength is not achieved by a hydraulic activation of the aggregates due to the higher temperature, as was assumed by the practitioners, but by a very early structure of prismatic Portlandites. In parallel with the development of the Portlandite structure, water is extracted from the mortar by the slaking reaction, which leads to earlier stiffening. During carbonation, this structure changes into a coarsely crystalline fabric made of scalenohedral-shape calcite. This structure and a distinctive shrinkage crack system explain the good moisture properties and salt resistance. These characteristics make the hot applied lime mortar seem suitable for special requirements in monument preservation and restoration. Where quick stiffening is important, for example when laying uneven field stones when securing the crown of ruins, when filling large cavities or joints, hot lime can ensure a faster construction process. Due to the good adhesion, the higher strength and salt resistance, hot lime mortars appear suitable for use where hydraulic systems based on cement or trass would normally be used, for example for plastering on masonry exposed to salt and moisture. This means that demanding tasks can be solved in pure lime technology, without the addition of alkalis or over-strengthening with hydraulic additives. Hot limewash is characterized by a higher layer thickness compared to limewash from lime putty. They are superior in their adhesion to the surface and are easy to process. As a result, they appear suitable to cover large areas fast. Another advantage, both of hot lime mortar and limewash, is the quick availability. Since there are no long slaking times to be taken into account or there is no need to dry-slake, small amounts of quicklime can be mixed as required and processed immediately. Due to the high temperatures, up to 80° C, and the high alkalinity of the mixtures, which requires special demands on health and safety measures, hot lime will only be used where other lime techniques do not achieve satisfactory results. As a result, the hot lime technology expands the possible uses of the historic building material lime.