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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo do emprego do Compactador Giratório Superpave na compactação de um solo argiloso / Study of the feasibility for using the Superpave Giratory Compactor in a clayey soil compaction

Dantas, Gustavo Henrique Santana 06 February 2013 (has links)
Esta pesquisa apresenta um estudo acerca da viabilidade do uso do Compactador Giratório Superpave (CGS) no ensaio de compactação de solos e mostra também um paralelo entre o ensaio de compactação Proctor e o ensaio de compactação no CGS. Para isso, foi selecionado um solo argiloso para ser submetido a ensaios de compactação Proctor e a ensaios de compactação com uso do compactador giratório. Nos ensaios com CGS foram utilizadas três tensões normais (200, 400 e 600 kPa) e corpos de prova de 1000g e 1800g. Também foi avaliado o comportamento mecânico de corpos de prova, moldados estaticamente e por amassamento, por meio dos ensaios de compressão simples, resistência a tração por compressão diametral e triaxial cíclico. No final, foi sugerido um procedimento de compactação de solos no CGS. Nos ensaios com o CGS, verificou-se que os valores de massa específica aparente seca (MEAS) (a) foram muito menores para os ensaios com 200 kPa que aqueles apresentados nas tensões de 400 kPa e 600 kPa; (b) apresentaram diferenças muito pequenas entre os ensaios de 400 e 600 kPa; (c) foram maiores para os CPs de 1000g que para os CPs de 1800g e (d) não tiveram ganho expressivo após 75 giros. A comparação entre as curvas de compactação Proctor e do CGS mostrou que os ensaios no CGS com tensão normal de 400 kPa e 600 kPa atingiram a massa específica seca máxima (MEAS máx) do Proctor Intermediário, mas não a do Proctor Modificado. Quanto aos ensaios mecânicos, os corpos de prova moldados no CGS apresentaram, de maneira geral, melhores resultados de resistência à compressão simples e resistência a tração por compressão diametral, enquanto que para o MR, observou-se uma tendência de melhor desempenho dos CPs moldados estaticamente. / This research presents the feasibility for using the Superpave Giratory Compactor (SGC) in soils compaction and a comparative evaluation between Proctor\'s and SGC\'s compaction processes. In order to evaluate the SGC compactor, a clayey soil was submitted SGC compaction tests at three normal stress (200, 400 and 600 kPa) and two different weight specimens (1000 and 1800 g). Mechanical tests to determinate the compression and tensile strength and resilient modulus were done on specimens compacted statically and by kneading. Additionally, it is suggested a compaction protocol test on SGC. About SGC\'s result tests indicated that dry densities values (a) at 200 kPa were lower than those obtained at 400 and 600 kPa; (b) at 400 and 600 kPa did not exhibit important variations (c) of 1000g specimens were higher than the 1800g ones and (d) did not increases after 75 number of gyrations. Regarding to mechanical properties, it can be detected that, in general, compression and tensile strength of SGC\'s specimens were better than the specimens compacted statically ones, and, as resilient modulus, specimens compacted statically had better perform than SGC\'s specimens
2

Estudo do emprego do Compactador Giratório Superpave na compactação de um solo argiloso / Study of the feasibility for using the Superpave Giratory Compactor in a clayey soil compaction

Gustavo Henrique Santana Dantas 06 February 2013 (has links)
Esta pesquisa apresenta um estudo acerca da viabilidade do uso do Compactador Giratório Superpave (CGS) no ensaio de compactação de solos e mostra também um paralelo entre o ensaio de compactação Proctor e o ensaio de compactação no CGS. Para isso, foi selecionado um solo argiloso para ser submetido a ensaios de compactação Proctor e a ensaios de compactação com uso do compactador giratório. Nos ensaios com CGS foram utilizadas três tensões normais (200, 400 e 600 kPa) e corpos de prova de 1000g e 1800g. Também foi avaliado o comportamento mecânico de corpos de prova, moldados estaticamente e por amassamento, por meio dos ensaios de compressão simples, resistência a tração por compressão diametral e triaxial cíclico. No final, foi sugerido um procedimento de compactação de solos no CGS. Nos ensaios com o CGS, verificou-se que os valores de massa específica aparente seca (MEAS) (a) foram muito menores para os ensaios com 200 kPa que aqueles apresentados nas tensões de 400 kPa e 600 kPa; (b) apresentaram diferenças muito pequenas entre os ensaios de 400 e 600 kPa; (c) foram maiores para os CPs de 1000g que para os CPs de 1800g e (d) não tiveram ganho expressivo após 75 giros. A comparação entre as curvas de compactação Proctor e do CGS mostrou que os ensaios no CGS com tensão normal de 400 kPa e 600 kPa atingiram a massa específica seca máxima (MEAS máx) do Proctor Intermediário, mas não a do Proctor Modificado. Quanto aos ensaios mecânicos, os corpos de prova moldados no CGS apresentaram, de maneira geral, melhores resultados de resistência à compressão simples e resistência a tração por compressão diametral, enquanto que para o MR, observou-se uma tendência de melhor desempenho dos CPs moldados estaticamente. / This research presents the feasibility for using the Superpave Giratory Compactor (SGC) in soils compaction and a comparative evaluation between Proctor\'s and SGC\'s compaction processes. In order to evaluate the SGC compactor, a clayey soil was submitted SGC compaction tests at three normal stress (200, 400 and 600 kPa) and two different weight specimens (1000 and 1800 g). Mechanical tests to determinate the compression and tensile strength and resilient modulus were done on specimens compacted statically and by kneading. Additionally, it is suggested a compaction protocol test on SGC. About SGC\'s result tests indicated that dry densities values (a) at 200 kPa were lower than those obtained at 400 and 600 kPa; (b) at 400 and 600 kPa did not exhibit important variations (c) of 1000g specimens were higher than the 1800g ones and (d) did not increases after 75 number of gyrations. Regarding to mechanical properties, it can be detected that, in general, compression and tensile strength of SGC\'s specimens were better than the specimens compacted statically ones, and, as resilient modulus, specimens compacted statically had better perform than SGC\'s specimens
3

Namrzavost zemin a druhotných materiálů v podloží vozovek / Frost susceptibility of soils and waste materials to pavement subgrade

Sokolová, Veronika January 2015 (has links)
Destruction of road constructions due to the frost is in locations with temperatures under the zero a problem which leads to permanent deformation. The theoretical part of this thesis deals with the freezing process of the pavement and its subgrade. It presents methods for determining the rate of frost susceptibility in both the Czech Republic and abroad. Describes the materials used in the subgrade of roads and their suitability in terms of frost susceptibility. The thesis closely examines the fly-ashes, their properties and possibilities of using in the construction industry. The practical part of the thesis focuses on the performance of direct laboratory frost heave tests, immediate bearing index tests, California bearing ratio tests and cyclic load triaxial tests to determine the modulus of elasticity. Tests are carried out on the soil, the soil mixtures with certain percentages of fly ash from different sources at the same soil treated with lime. Then the results are compared and dependence between the measured characteristics of materials is created.
4

Namrzavost nestmelených směsí vozovek pozemních komunikací / The frost susceptibility of unbound mixtures to pavements

Surá, Kateřina January 2016 (has links)
The thesis is focused on the analysis of the theoretical part of the unbound mixtures, their implementation and compliance. Further deals with determining the extent frost susceptibility direct and indirect method in the Czech Republic and the Member States of the European Union. The practical part is focused on the performance of tests on selected samples of unbound mixtures for which was gradually increased the content of fine particles and that direct and indirect method of determining the rate of frost susceptibility and also the evaluation of direct methods of particular customized way, which does not impose the appropriate standard. At the conclusion of the work is carried out an evaluation of the samples and comparison of the different methods with each other.
5

Namrzavost zemin a materiálů v podloží vozovek / The frost susceptibility of the soils and materials to subgrade of the pavements

Mašek, Jakub January 2013 (has links)
This diploma thesis deals with the issue of the determination of the frost susceptibility of soils in the subgrades of road structures. The theoretical part compares the ways of testing the frost susceptibility in the Czech Republic and other selected countries of the European Union. Furthermore, it also deals with the development of the frost susceptibility index in the Czech Republic. The empirical part focuses on the laboratory testing of the frost susceptibility of the given sample of soil by the direct frost heave method. Moreover, it also deals with the simulation of penetration of frost by the subgrade and the possibility of shortening the length of the freezing during the direct testing the frost susceptibility.

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