Extensive published literature shows that hydrated lime improves Hot Mix Asphalt (HMA) durability. Its impact on the environmental impact of HMA has not been investigated. This paper presents a comparative Life Cycle Assessment (LCA) for the use of HMA without hydrated lime (classical HMA) and with hydrated lime (modified HMA) for the lifetime of a highway. System boundaries cover the life cycle from cradle-to-grave, meaning extraction of raw materials to end of life of the road. The main assumptions were: 1. Lifetime of the road 50 years; 2. Classical HMA with a life span of 10 years, maintenance operations every 10 years; 3. Modified HMA with an increase in the life span by 25%, maintenance operations every 12.5 years. For the lifetime of the road, modified HMA has the lowest environmental footprint compared to classical HMA with the following benefits: 43% less primary total energy consumption resulting in 23% lower emissions of greenhouse gases. Partial LCAs focusing only on the construction and/or maintenance phase should be used with caution since they could lead to wrong decisions if the durability and the maintenance scenarios differ. Sustainable construction technologies should not only consider environmental impact as quantified by LCA, but also economic and social impacts as well. Avoiding maintenance steps means less road works, fewer traffic jams and hence less CO2 emissions.

Low temperature cracking is an important form of asphalt pavement deterioration in cold regions. The cracks develop when thermally induced stresses exceed the fracture resistance of the asphalt pavement. In this study, by incorporating HMA fracture mechanics into thermal cracking model, a new integrated model is introduced to investigate low temperature cracking performance. To evaluate its reliability and accuracy, the predicted thermally induced stress and failure temperature are compared with the fracture stress and fracture temperature obtained from thermal stress restrained specimen test. The findings indicate that this HMA fracture mechanics-based thermal cracking model has a great potential to reliably evaluate the performance of asphalt mixtures subjected to thermally induced damage.

No Brasil, desde o início da década de 1990, vêm sendo desenvolvidas pesquisas sobre aplicação do asfalto-borracha visando tanto a diminuição dos problemas ambientais gerados pelo descarte de pneus inservíveis, como a melhoria das características dos ligantes produzidos. Dentro desse contexto, esta pesquisa teve por objetivo avaliar o desempenho mecânico de oito misturas asfálticas do tipo concreto asfáltico usinado a quente, produzidas com asfaltos convencional e convencional modificado com borracha de pneu e resíduo de óleo de xisto. Quanto ao ligante, foram utilizados 8 tipos, a saber: CAP 30/45 (referência); dois ligantes empregando teores diferentes de borracha moída de pneu; outros dois com teores distintos de resíduo de óleo de xisto e, por fim, mais três com combinações de teores de borracha e de resíduo de óleo de xisto. Os corpos-de-prova empregados nos ensaios foram moldados em cinco teores diferentes de ligantes asfálticos (4,5; 5,0, 5,5; 6,0 e 6,5%). Conseqüentemente, foram realizados ensaios Marshall, resistência à tração, módulo de resiliência e umidade induzida. Com base nos resultados dos ensaios realizados observou-se que tanto a borracha quanto o óleo reduzem a resistência à tração e o módulo de resiliência das misturas, no entanto, na recuperação retardada, os efeitos da borracha e do óleo são antagônicos, diminuindo e aumentando, respectivamente. Ademais, quanto à suscetibilidade à ação da água, as misturas com adição de óleo apresentaram menor suscetibilidade que as misturas com adição de borracha. Além disso, foi observado que todas as misturas estudadas, exceto aquelas com altas concentrações de óleo e de borracha, atenderam os requisitos estabelecidos pelas especificações, para as propriedades analisadas. Todavia, em alguns casos, considerando os efeitos antagônicos do óleo e da borracha, algumas combinações entre ambos podem ser realizadas, com a finalidade de alcançar os níveis desejados para as propriedades do ligante asfalto-borracha e das misturas asfálticas. / In Brazil, since the beginning of the 90\'s, have been developed researches on the application of asphalt-rubber seeking the reduction of environmental problems created by the used tires, and the improvement of the characteristics of the produced binder. Taking this into account, the purpose of this research is to evaluate the mechanical performance of eight hot mix asphalt concretes, produced with conventional asphalt and modified asphalt with crumb rubber and shale-oil residue. Eight types of binders were used: CAP 30/45 (reference); two binders using different crumb rubber contents, two with different shale-oil residue contents, and finally three more with the combination of crumb rubber and shale-oil residue contents. The specimens used in the laboratorial tests were compacted in five different binders contents (4.5; 5.0, 5.5; 6.0 e 6.5%). Hence, the tests performed are: Marshall test, indirect tension, resilient modulus and moisture induced. The results showed that the rubber and the shale oil reduce the indirect tension and resilience module of the mixtures, however, on the delayed recover, the effects of the rubber and of the shale oil are opposed, decreasing and increasing it, respectively. Moreover, for the moisture susceptibility, the mixtures with shale-oil residue exhibited less susceptibility to water than those with crumb rubber. Furthermore, all the studied mixtures, except those with high shale-oil residue and rubber concentrations, they got to attend the established requirements for the specifications, for the analyzed properties. Although, in some cases, considering the opposed effects of the shale oil and of the crumb rubber, some combinations between both can be accomplished, with the purpose of reach the levels wanted for the properties of the asphaltrubber binder and the asphalt mixtures. Also regression models were elaborated as for the analyzed properties. The results obtained of modeling were satisfactory.

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No. of bitstreams: 2 Dissertação - Carolina Queiroz Arantes Prudente - 2015.pdf: 2676423 bytes, checksum: 95fa022b3853b805c569eb33d3d481e4 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) Previous issue date: 2015-08-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Flexible or asphalt pavements compose the Brazilian highway network, which have to promote security on traffic on the highways, to support the effects of changes in climate and to resist the traffic of vehicles. By this reasons, the structure of the pavement is particularly important and must be constituted by layers, which can distribute the loads into the structure, reducing the vertical load produced by the action of traffic and, consequently, providing protection to the subgrade. In the middle western Brazil, in the state of Goiás, there is not advanced studies on asphalt mixtures used in highways and in urban pavements, and there is not a technical scientific proofing that the local aggregates available in the region, is the best option considering the local conditions. Forward better conditions of infrastructure, it is proposed to develop more efficient asphalt mixtures for pavements, by submitting the mixtures through analysis of mechanical strength and performance test, analyzing if the most used asphalts mixtures are satisfactory or not. The hot asphalt mixture are composed by aggregates and asphalt binders that are design in order to attend the parameters set in the projects according to demand and traffic types. In this research, it was proposed the study of six asphalt mixture design with different types of asphalt binders with the same aggregates origin in a different grain size range (Bands B and C). The binders used in this study are the conventional cement asphalt in the region, CAP 30/45 e 50/70 (Brazilian penetration grade), with low and medium penetration, respectively, and the polymer modified asphalt (AMP). The CAP 50/70 is the most used conventional binder in the region, followed by CAP 30/45. Tha AMP binder is not often used. The characterization tests of the materials that composed the mixture are presented and their selection and characterization attended the standardized procedures and requirements by the brazilian department responsible for highway structures (DNIT). In a second stage, the design tests were performed, combining aggregates and binders in different rates, by the Marshall Mix Design Method using manual compression, until the great design was obtained The laboratory tests were realized with this great design to analyze the mass loss and obtain its mechanical properties, given by the tensile strength (RT). Performance tests were realized to obtain its resilient modulus (MR) and, using wheel tracking test, to obtain the permanent deformation (DP). The results showed that the common hot mixture asphalt used in the region (range C and CAP 50/70), is not a good option, because its performance is not satisfactory. Therefore, the range to be used, and the binder, must be analyzed for each traffic level. It is also recommended to evaluate the Marshall methodology for design mixtures, considering mainly the compression way and the determination of the maximum densities. / A malha rodoviária brasileira é composta, principalmente, por pavimentos do tipo flexível ou asfáltico, que devem, para promover a segurança ao tráfego nas rodovias, suportar os efeitos das mudanças de clima e resistir ao fluxo de veículos. Para isso, a estrutura do pavimento é particularmente importante e deve ser constituída por camadas que distribuam as cargas a que estão submetidas, minimizando os esforços verticais produzidos pela ação do tráfego e, consequentemente, oferecendo proteção ao subleito. Em busca de melhores condições de infraestrutura no estado de Goiás, propôs-se avaliar se as misturas asfálticas mais utilizadas na região são consideradas satisfatórias ou não, visto que inexistem estudos desenvolvidos sobre o assunto. As misturas asfálticas a quente são compostas de agregados e ligantes, que são dosados de forma a atender os parâmetros determinados nos projetos de acordo com a demanda e tipos de tráfego. Nesta pesquisa, foi proposto o estudo da dosagem de seis projetos de misturas, com diferentes tipos de ligantes asfálticos para agregados de mesma origem nas faixas granulométricas mais utilizadas na região (Faixas B e C). Foram utilizados ligantes convencionais CAP 30/45 e 50/70, com baixa e média penetração, respectivamente, e asfalto modificado com polímero (AMP). Dos ligantes convencionais, o CAP 50/70 é o mais utilizado na região, seguido do CAP 30/45, já o AMP ainda não é frequentemente utilizado. Foram realizados ensaios de caracterização dos materiais que compõem as misturas, que seguiram os procedimentos e requisitos normatizados pelo Departamento Nacional de Infraestrutura de Transportes (DNIT). Em uma segunda etapa, foram realizados ensaios de dosagem, combinando agregados e ligantes em diferentes taxas até que, por meio da metodologia Marshall com compactação manual, fosse obtida a dosagem considerada ótima para cada mistura estudada. Com essas dosagens, foram realizados ensaios em laboratório, para análise de desgaste, de desempenho das misturas e de suas propriedades mecânicas, por meio da determinação da resistência à tração por compressão diametral, do módulo de resiliência e da deformação permanente. Os resultados obtidos demonstraram que a mistura asfáltica mais comum de ser utilizada como camada de rolamento na região (Faixa C e CAP 50/70) não apresenta comportamento satisfatório. Dessa forma, a faixa granulométrica a ser utilizada deve ser repensada, bem como o tipo de ligante a ser utilizado para cada nível de tráfego. Recomenda-se, também, a reavaliação da utilização da metodologia Marshall para dosagem das misturas, principalmente na questão da forma de compactação e na determinação das densidades máximas.

No Brasil, desde o início da década de 1990, vêm sendo desenvolvidas pesquisas sobre aplicação do asfalto-borracha visando tanto a diminuição dos problemas ambientais gerados pelo descarte de pneus inservíveis, como a melhoria das características dos ligantes produzidos. Dentro desse contexto, esta pesquisa teve por objetivo avaliar o desempenho mecânico de oito misturas asfálticas do tipo concreto asfáltico usinado a quente, produzidas com asfaltos convencional e convencional modificado com borracha de pneu e resíduo de óleo de xisto. Quanto ao ligante, foram utilizados 8 tipos, a saber: CAP 30/45 (referência); dois ligantes empregando teores diferentes de borracha moída de pneu; outros dois com teores distintos de resíduo de óleo de xisto e, por fim, mais três com combinações de teores de borracha e de resíduo de óleo de xisto. Os corpos-de-prova empregados nos ensaios foram moldados em cinco teores diferentes de ligantes asfálticos (4,5; 5,0, 5,5; 6,0 e 6,5%). Conseqüentemente, foram realizados ensaios Marshall, resistência à tração, módulo de resiliência e umidade induzida. Com base nos resultados dos ensaios realizados observou-se que tanto a borracha quanto o óleo reduzem a resistência à tração e o módulo de resiliência das misturas, no entanto, na recuperação retardada, os efeitos da borracha e do óleo são antagônicos, diminuindo e aumentando, respectivamente. Ademais, quanto à suscetibilidade à ação da água, as misturas com adição de óleo apresentaram menor suscetibilidade que as misturas com adição de borracha. Além disso, foi observado que todas as misturas estudadas, exceto aquelas com altas concentrações de óleo e de borracha, atenderam os requisitos estabelecidos pelas especificações, para as propriedades analisadas. Todavia, em alguns casos, considerando os efeitos antagônicos do óleo e da borracha, algumas combinações entre ambos podem ser realizadas, com a finalidade de alcançar os níveis desejados para as propriedades do ligante asfalto-borracha e das misturas asfálticas. / In Brazil, since the beginning of the 90\'s, have been developed researches on the application of asphalt-rubber seeking the reduction of environmental problems created by the used tires, and the improvement of the characteristics of the produced binder. Taking this into account, the purpose of this research is to evaluate the mechanical performance of eight hot mix asphalt concretes, produced with conventional asphalt and modified asphalt with crumb rubber and shale-oil residue. Eight types of binders were used: CAP 30/45 (reference); two binders using different crumb rubber contents, two with different shale-oil residue contents, and finally three more with the combination of crumb rubber and shale-oil residue contents. The specimens used in the laboratorial tests were compacted in five different binders contents (4.5; 5.0, 5.5; 6.0 e 6.5%). Hence, the tests performed are: Marshall test, indirect tension, resilient modulus and moisture induced. The results showed that the rubber and the shale oil reduce the indirect tension and resilience module of the mixtures, however, on the delayed recover, the effects of the rubber and of the shale oil are opposed, decreasing and increasing it, respectively. Moreover, for the moisture susceptibility, the mixtures with shale-oil residue exhibited less susceptibility to water than those with crumb rubber. Furthermore, all the studied mixtures, except those with high shale-oil residue and rubber concentrations, they got to attend the established requirements for the specifications, for the analyzed properties. Although, in some cases, considering the opposed effects of the shale oil and of the crumb rubber, some combinations between both can be accomplished, with the purpose of reach the levels wanted for the properties of the asphaltrubber binder and the asphalt mixtures. Also regression models were elaborated as for the analyzed properties. The results obtained of modeling were satisfactory.

No description available.

In this diploma thesis there are described the issues use of foamed bitumen as binder in asphalt mixtures. The thesis is divided into two parts, theoretical and practical. The aim of theoretical part was to elaborate an overview of technologies, which allow to reduce the temperature during the production and laying of asphalt mixtures. The aim of the practical part was to compare the selected empirical and functional parameters of two types of asphalt mixtures produced in two variants, with hot bitumen and foamed bitumen. Attention was paid mainly to stiffness and low temperature parameters.

The diploma thesis deals with the production of warm mix asphalts, using the foam bitumen technology. The thesis is divided into theoretical and practical part. The theoretical part is focused on the basic division of roadway constructions, particularly on warm mix asphalts. The aim of the practical part was to find out whether the produced asphalt mixture retains its functional properties when the operating temperature is reduced. For this purpose, two asphalt mixtures of the ACO 11+ type at operating temperature of 150 °C and reduced operating temperature of 130 °C were made. Functional tests and empirical and functional tests were carried out on the produced asphalt mixtures and the extracted bitumen binders respectively. In the conclusion of the thesis, the results of the tests are mutually compared.

The diploma thesis is divided into theoretical and practical part. The theoretical part is mainly focused on methods for reducing the working temperature in the production of hot mix asphalt and the main reasons for this. Most attention is paid to the warm mix asphalt, mainly foam asphalt technology. In practical part are describes working procedures of individual tests on asphalt mixtures and recovered bitumen binders. The tests were performed on 3 types of ACO 11+, one was made with working temperature 160°C without foamed bitumen and the other two with foamed bitumen,one with working temperature 160°C and the second 140°C. Then were the results compared.