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Cold recycling of flexible pavements
Řehulka, Martin ; Koudelka, Tomáš (referee) ; Varaus, Michal (advisor)
The bachelor´s thesis is focused on recycling of the flexible pavements in general, namely cold recycling. This modern technology was introduced in the Czech Republic after 1989. The first half of the thesis describes theoretically various types of recycling of flexible pavements, where the greatest attention is paid to this technology. The second part describes the section of the modernization D1 motorway where this cold recycling was applied. The technological process, including visual documentation and control tests, is documented.
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Prediction of road surface skid resistance in laboratory
Nekulová, Pavla ; Dašek, Ondřej (referee) ; Stryk, Josef (referee) ; Varaus, Michal (advisor)
The dissertation deals with a testing method described in ČSN EN 12697-49 (also known as Wehner/Schulze), which aims to predict the evolution of skid resistance properties of road surfaces using laboratory testing. Given that the required quality of skid resistance on road surfaces must be met not only for new constructions but also at the end of the warranty period, contractors of transportation structures have started focusing on the lifespan of road skid resistance properties. Although the Wehner/Schulze test was introduced in the 1960s, increased attention has been given to it only in the last fifteen years. The fundamental prerequisite for utilizing this testing method is linking the measurement results in the laboratory to values measured by dynamic measuring devices, commonly used for monitoring the skid resistance of road surfaces. This involves establishing a relationship between laboratory simulation of traffic and actual traffic load. The final step involves employing the Wehner/Schulze testing method to design special asphalt mixtures with optimal longevity of skid resistance properties. In this case, it entails an asphalt mixture with a combination of aggregates with different PSV values to utilize local aggregates with low PSV values, supplemented with a small quantity of high-quality imported aggregates with high PSV values.
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New trends in the field of stone mastic asphalts
Pfeiferová, Magdaléna ; Varaus, Michal (advisor)
The work consists of two parts. The first part is focused on the determination of an anti-skid properties of the test section on Vídenská street. The anti-skid properties will be measured using a pendulum tester and macrotexture will be set at the same time. Microtexture will be measured using a volumetric patch technique. In the second part we will try to gain an initial experience with design and testing of a low noise stone mastic asphalt. We will set basic characteristics and at the same time compare with a standard stone mastic asphalt. For the comparison two various bituminous binders are used. The water sensitivity, resistance against rutting and stiffness moduli are compared.
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Night-time visibility of horizontal road marking
Fišer, David ; MBA, Martin Tóth, (referee) ; Varaus, Michal (advisor)
This work is focused on important characteristic of horizontal road marking, which is night-time visibility, or retroreflection. Introductoty part deals with characteristics of horizontal road marking with emphasis on night-time visibility, contains summary of materials used for marking, material on drop, and also various kinds and technologies of application of horizontal marking. Next part is devoted to methods of measurement and their description including equipment for measurement. In the practical part there are listed data from measurement of retroreflection made on test area and on chosen areas of roads and also evaluation of measured data. End of this work includes obtained knowledges and review summary.
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Design of low-temperature asphalt mixtures
Líšková, Jana ; Zajíček, Jan (referee) ; Varaus, Michal (advisor)
In this diplomatic work, the issue of low-temperature asphalts and binders for asphalt mixtures is solved. Diploma work is divided into two parts, theoretical and practical. In the theoretical part of diploma work, the purpose was to process a overview of technologies that allow the reduction of working temperature in the production and laying of asphalt mixtures. The purpose of the practical part was to comparison the functional parameters of two types of asphalt mixtures made in two variants, with the common asphalt binder and adding licomont into asphalt. Attention was given to stiffness, wheel drive tests and low temperature parameters.
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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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