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Ageing of asphalt binders
Střasáková, Monika ; Hegr, Zdeněk (referee) ; Dašek, Ondřej (advisor)
The theoretical part of this thesis describes the rheology of bituminous binders, aging of asphalt binders and laboratory methods simulating short and long term aging. The following describes an empirical tests (needle penetration, softening point ring ball method) and functional tests (complex shear modulus and phase angle, dynamic viscosity), which are performed in the dynamic shear rheometer. At the end of this section, laboratory aging of bituminous binders using method RTFOT and method RTFOT + PAV is described in more detail. In the practical part of this thesis, the results of all tests performed on the binders aged using RTFOT + PAV are introduced and compared with results of properties of non-aged binders and binders aged by 3xRTFOT.
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Recycling of bituminous binders by using recycling agents
Koudelka, Tomáš ; Komačka,, Jozef (referee) ; Dašek, Ondřej (referee) ; Varaus, Michal (advisor)
Increasing the content of Reclaimed Asphalt in hot asphalt mixtures is one of the current issues in road construction, to which society's attention is paid. The higher content of Reclaimed Asphalt brings higher technological demands not only for the production of asphalt mixture plants, but also for the handling of materials in general. The benefit for higher demands on asphalt mixture production is the subsequent reduction of the environmental burden associated with the construction of road infrastructure caused by the mining industry and use of natural resources. The dissertation is focused on studying recycling agents which are used in the production of asphalt mixtures containing Reclaimed Asphalt. Emphasis is put on comparing the properties of recycled binders with paving bitumen and binders from Reclaimed Asphalts whereas the effect of repeated recycling is taken into account. A large part of the thesis is devoted to the design of the optimal dosage of recycling agents. Certain findings were used to draw a methodology describing the design of dosing of these agents. At the same time, the properties and behaviour of the recycling agents themselves were evaluated.
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Shear stress relaxation of bituminous binders in DSR
Musil, Vladimír ; Hegr, Zdeněk (referee) ; Dašek, Ondřej (advisor)
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.
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Usage of thin wearing courses with highly polymer modified bitumen
Renza, Jaroslav ; Rous, Vojtěch (referee) ; Dašek, Ondřej (advisor)
The diploma thesis deals with technology for the implementation and use of asphalt concrete for very thin layers (BBTM) with use of asphalt binder of high-polymer modification (HiMA). Further, there are described selected and performed functional tests. Thesis also contains design of a mixture for bituminous concrete type targeted for very thin layers with different types of binders. After a suitable design of the mixture, laboratory tests were carried out (stiffness modulus, resistance to permanent deformation, low temperature characteristics, water resistance and particle loss). The output of this work is a set of measured values and processed results with their interpretation.
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Application of crumb rubber in bituminous binders and in bituminous mixtures
Dašek, Ondřej ; Fišer,, Jiří (referee) ; Vacín,, Otakar (referee) ; Komačka,, Jozef (referee) ; Kudrna, Jan (advisor)
Presented dissertation thesis is focused on the possibility of using the crumb rubber from waste tires for modification of paving grade bitumen. The resulting asphalt rubber can be used as an alternative to polymer modified bitumen in compacted bituminous mixtures. The theoretical part describes the rheological properties of asphalt binders and the history and today state of the art in the world and in the Czech Republic. The practical part of the work contains a description of the properties of chosen crumb rubbers and produced asphalt rubbers focused on their rheological properties and on change of these properties caused by the aging at high temperature. Subsequently, the chosen empirical and functional properties of bituminous mixtures with asphalt rubber are described. Laboratory properties of these mixtures were verified under real service conditions on 32 test sections. Based on the dissertation thesis results the preliminary technical specification of the Ministry of Transport (TP 148) and their following revision were approved. The conclusion of the work summarizes and highlights the results of the dissertation.
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Evaluation of properties of PMB containing binder from RAP
Měšťanová, Petra ; Hýzl, Petr (referee) ; Dašek, Ondřej (advisor)
Subject of this diploma thesis is to describe the effect of adding different amount of aged binder recovered from RAP on the change of properties of polymer modified bitumen. The RAP containing unmodified bitumen and the RAP where we can expect bitumen modification are used to recover binder. The binder obtained from RAP is dosed into the virgin binder in amount of 15 %, 30 % and 50 %. The methods of recycling of flexible pavements, extraction and regeneration of asphalt binders, rejuvenating of their properties and methods of empirical and functional laboratory tests are described in the theoretical part. The practical part deals with evaluating and comparison of the results mixed binders properties.
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Influence of temperature on the penetration of asphalt binders
Koblížek, Ondřej ; Koudelka,, Tomáš (referee) ; Dašek, Ondřej (advisor)
The bachelor thesis deals with an influence of temperature on the needle penetration results of tested bitumens in various test temperatures. The theoretical part describes the issue of laboratory tests in the world. This work also describes the american research program called SHRP (American Highway Research Program). The following part explains used test methods in detail (determination of needle penetration, determination of the softening point – ring and ball method). The practical part briefly introduces used materials and determines the results of laboratory tests and their comparison.
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Properties of reinforcing glass-fiber geogrids
Veselý, Petr ; Šperka, Pavel (referee) ; Dašek, Ondřej (advisor)
A proper road infrastructure is an essential part of today’s economy. Usage of roadways should be safe and its flow should be easy going. Primary net of roadways is already in place and attention shifts to its maintenance. Because of constantly increasing loads of heavy traffic, roadways are degrading at a faster pace, while there are still smaller time windows and less avialable resources for their reconstruction. That is why there has been rising demand for pavements that last longer and are able to carry higher weights. With respect to the rural roads it becomes obvious because of low amount of resources for their maintenance, that it is necessary to find an effective way to enhance pavements. From the foregoing it can be safe to say, that there is a clear need for reliable, durable and cost-effective technology of maintenance, such as the use of grids in asphalt pavements. This thesis deals with properties of geogrids made of glass fiber after its compaction as well as its effects on reduction or elimination of spreading of cracks in pavements.
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Asphalt layers with reinforcing glass-fiber geogrids
Sachr, Jiří ; Bohuš,, Štěpán (referee) ; Dašek, Ondřej (advisor)
This diploma thesis deals with the use of glass fiber geogrids and geocomposites in road construction. The reinforcement elements are inserted between the wearing and binder asphalt layer. This diploma thesis summarizes the knowledge connected with reinforcing of asphalt roads using glass fiber. It examines the effect of reinforcing fiberglass elements on the resistance of asphalt layers loaded with traffic. At the same time, it deals with the application of a various amount of tack coat and subsequent behavior of the asphalt layers. In this work, laboratory tests of bond strength between layers on cores and four-point bending were performed.
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