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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.
21

Análise dos efeitos da borracha moída de pneu e do resíduo de óleo de xisto sobre algumas propriedades mecânicas de misturas asfáticas densas / Analysis of the effects of crumb rubber and shale-oil residue on mechanical properties of asphalt mixtures

Fernanda Pilati 27 March 2008 (has links)
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.
22

Návrh a posouzení asfaltového betonu pro ložní vrstvy s asfaltem modifikovaným pryžovým granulátem / Design and evaluation of asphalt rubber mixture for pavement binder course

Musílek, Lukáš January 2013 (has links)
The design of asphalt concrete for binder courses with high-viscosity asphalt rubber and low-viscosity asphalt rubber is carried out in the diploma thesis. Selected performance tests (low temperature characteristics, stiffness and fatigue) and water sensitivity are performed for these mixtures. Results are compared each other.
23

Porovnání švédského a amerického konceptu návrhu směsí s CRmB / Swedish and US AR mixture design comparison

Puda, Adam January 2015 (has links)
This master's theseis deals with comparison of two design concepts for producting asphalt mixture with CRmB. These design concepts are from Sweden and USA. The theoretical part sets parameters for design of asphalt mixture and chracteristic tests. In the practical part test speciements of design asphatl mixture undergo performace tests that simulate climate and traffic load. Results are compared to mathematical model used in program LayEps.
24

Relaxace smykového napětí asfaltových pojiv v DSR / Shear stress relaxation of bituminous binders in DSR

Musil, Vladimír January 2015 (has links)
The thesis describes the relaxation properties of bituminous binders determined in dynamic shear rheometer (DSR). Paving bitumen, polymer modified bitumen (PMB) and crumb rubber modified bitumen (CRmB) were chosen for comparison. In order to describe the effects of ageing on asphalt binders relaxation properties, the laboratory simulation of ageing using RTFOT and 3xRTFOT method was performed. For each binder were simultaneously conducted tests of needle penetration, softening point and elastic recovery. Selected bitumens were used for the production of asphalt mixtures. The low-temperature properties tests (TSRST) were performed for these mixtures, when the results were compared to the relaxation properties of binders determined in the DSR.
25

Vliv obsahu pojiva na vlastnosti asfaltové směsi s CRmB / The influence of bitumen content on properties of asphalt mixture with CRmB

Sychra, Martin January 2016 (has links)
The asphalt mixture BBTM 5 A with crumb rubber modified bitumen (CRmB) is designed and produced in the diploma thesis. The influence of CRmB content on low temperature properties, stiffness and fatigue of asphalt mixture BBTM 5 A is determined. The influence of asphalt mixture ageing simulation on change of low temperature properties is also evaluated.
26

Asfaltové směsi s vyšší životností za použití R-materiálu / Bituminous mixtures with a higher lifetime using recycled asphalt

Stromecký, Roman January 2019 (has links)
This diploma thesis deals with a project of asphalt mixtures with high stiffness modulus using R-material. The theoretical part describes the characteristics of these mixtures in the Czech Republic and in Switzerland. Further this part deals with the use of R-material in the Czech Republic and chosen other countries of the world, it also deals with the ways of recycling roads. The theoretical part also deals with the testing methods used. In the practical part two new asphalt mixtures of the high stiffness modulus type with the addition of 25 % R-material are suggested. As a base for these two mixtures a mixture of the high stiffness modulus type, which was taken from an asphalt mixing plant, was used. Tests were run on the binders and several functional tests (stiffness modulus, fatigue resistance, low temperature qualities) wer done on the suggested asphalt mixtures and also the mixture taken from the mixing plant. Consequently, the results were compared. The conclusion of the thesis is devoted to modelling a construction of a road using the program LayEps, which verified if the suggested mixtures could reduce the thickness of roads.
27

Inovativní asfaltové směsi pro netuhé vozovky s použitím R-materiálu / Inovative asphalt mixtures to flexible pavement structure with using reclaimed asphalt

Horáček, Daniel January 2020 (has links)
The diploma thesis is focused on the design and production of two innovative asphalt mixtures of the VMT 22 type into the base asphalt course. The newly produced blends contain modified binders, such as polymer modified bitumen (PMB) and Crumb rubber modified bitumen (CRMB). The theoretical part of the thesis describes the current state of the use of Reclaimed asphalt pavement in the base asphalt course. Furthermore, there are described types of asphalt mixtures for the base asphalt course are used in the Czech Republic and other countries. The conclusion of the theoretical part is devoted to the description of Reclaimed asphalt pavement (RAP), its storage and processing in a hot mix center. In the practical part of this thesis, there is described design and test of two High modulus asphalt mixture VMT 22, into which 25% RAP is dosed cold without rejuvenators. These asphalt mixtures are then subjected to functional tests (Stiffness of asphalt mixture test, Resistance to fatigue test, Low temperature properties of asphalt mixture test). The results of the functional tests are compared with the functional requirements in the Czech regulation TP 151. In the end of this thesis it is verified by means of the LayEps software that a suitable design of the asphalt mixture can significantly extend the road life.
28

Vyhodnocování dopravního hluku a jeho modelování / Evaluation and modelling of Traffic Noise

Černoch, Adam January 2014 (has links)
The task of the master's thesis is introduction with the problems of traffic noise, focusing on noise from road traffic. There is a description what is the noise, how it is formed, its resources and what are the methods of measuring. The following are the various noise reduction measures such as noise barriers and low noise pavements. The main attention is devoted to the noise generated at the tire / road that is reduced by these pavements. The practical part describes the implemented measurements on individual sections at various locations in our country. The measurement was carried by slightly modified method CPX with reference tire directly at the vehicle. The main aim was to evaluate the measurement data, make comparison of different low-noise surfaces with each other and with the commonly used surfaces. Then quantification of the rate reduction of the noise emission for a given section and verification of input data for noise modeling. In conclusion, the obtained results are summarized and based on them were confirmed very good acoustic properties with the recommendation to continue with measurements in the future.
29

Inovativní asfaltové směsi pro obrusné vrstvy s použitím vyššího množství R-materiálu / Innovative Asphalt Mixtures for Wearing Course with a Higher Content of Reclaimed Asphalt Pavement

Spies, Karel Unknown Date (has links)
This master's thesis deals with the design of two asphalt mixtures for a wearing course containing 35 % R-material. The asphalt mixtures use a soft bitumen modified with crumb rubber (CRMB) or the unmodified soft binder itself with a penetration grade of 70/100. The work verifies the effect of crumb rubber as a bitumen modifier on the properties of the asphalt mixture with reclaimed asphalt pavement (RAP). At the same time, the work deals with the possibility of using higher amounts of reclaimed asphalt pavement only in combination with a softer binder without the use of rejuvenating additives. The properties of asphalt binders and mixtures are verified using suitable functional tests. Furthermore, the proposed mixtures and their results are compared from various perspectives. At the same time, the thesis in the theoretical part deals with the dosing of a reclaimed asphalt pavement into the asphalt mixture and describes the handling and use of reclaimed asphalt pavement in the Czech Republic and abroad

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