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Modification of asphalt mixtures
Zeleňák, Matej ; Hýzl, Petr (referee) ; Dašek, Ondřej (advisor)
This master’s thesis studies impact of direct-to-plant SBS polymer on properties of asphalt binder and asphalt mixture. It uses a new modification additive. The addition takes place directly during the mixing in the plant. This technology is not commonly used in Czech Republic. The theoretical part of this thesis describes current experiences with this method of modification. The procedures of laboratory tests needle penetration, softening point, elastic recovery, stiffness and low-temperature properties are described. The practical part presents values measured during preparation of test samples. Furthermore, it analyses the test results of the binders and mixtures in detail. The thesis concludes by evaluation of each test result and by summarization of the findings.
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The evaluation of properties of fine aggregate for asphalt mixtures
Kadlček, Jakub ; Sychra, Martin (referee) ; Dašek, Ondřej (advisor)
The diploma thesis is focused on evaluation of properties of fine aggregate by means of laboratory tests. Fine aggregate evaluation was performed using sieving test, laser diffraction, delta ring and ball test, bitumen number test, uncompacted void content of fine aggregate according to AASHTO T 304, voids of dry compacted filler (Rigden) test and particle density of filler. Laboratory research has led to the discovery of some properties of fine aggregate and their dependencies.
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Coarse-grained asphalt concretes
Škorík, Michal ; Dašek, Ondřej (referee) ; Hýzl, Petr (advisor)
This diploma thesis deals with the design of coarse-grained asphalt concrete for base courses with aggregates up to 32 mm in size. The theoretical part describes current issues related to the shortage of natural aggregate in the Czech Republic and introduces the reader to the knowledge of coarse-grained asphalt mixtures used in the Czech Republic and abroad. The practical part focuses on the design of asphalt mixtures for base courses AC 32 50/70. It further describes in detail the process of laboratory production of the asphalt mixture and individual functional and empirical tests. In the last part parameters as modulus of stiffness, resistance to low temperatures and resistance to permanent deformations are evaluated.
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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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Issue of asphalt mixtures with coarse-grained aggregates
Koblížek, Ondřej ; Hýzl, Petr (referee) ; Dašek, Ondřej (advisor)
The diploma thesis deals with the design of asphalt mixture of asphalt concrete type for base courses with maximum aggregate grain up to 32 mm and investigates the influence of the amount of asphalt binder on the properties of this mixture. The theoretical part describes the problem of aggregate shortage in the Czech Republic and the division of aggregates into various categories. In the next part, the laboratory used tests (needle penetration determination, softening point determination, compaction degree, determination of the stiffness modulus, low temperature properties and wheel tracking) are described in detail. The practical part describes the used materials, the results of the laboratory tests, their comparison and evaluation.
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Coarse-grained asphalt mixtures
Brida, Peter ; Hýzl, Petr (referee) ; Dašek, Ondřej (advisor)
The diploma thesis is focused on the comparison of the influence coarse-grained aggragate on the properties af asphalt concrete. The theoretical part describes issue of production and usage of asphalt mixtures. The practical part evaluates multiple types of asphalt mixtures and describing their properties. Stiffness by a two-point bending test, a wheel tracking test and low-temperature cracking and properties by uniaxial tension test were used to evaluate the properties of the mixtures.
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Use of fluxing additives to modify the properties of asphalt binders
Šefránková, Radka ; Koudelka, Tomáš (referee) ; Dašek, Ondřej (advisor)
The subject of the thesis is to describe the effect of fluxing additives on the behaviour of asphalt binders. Emphasis will be placed on changes in rheological properties of asphalt binders at intermediate temperatures, stability during aging and influence of fluxing agents on their low-temperature properties. Theoretical part will deal with the principle of asphalt binders aging and it will summarize knowledge about fluxing additives. Further, empirical and functional tests will be described in order to evaluate asphalt binders. In the practical part, all laboratory tests will be evaluated and the effects of two different fluxing additives will be compared.
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Use of RAP in coarse-grained asphalt mixtures
Teslík, Jozef ; Dašek, Ondřej (referee) ; Hýzl, Petr (advisor)
The diploma thesis examines the possibilities of using R-material in coarse-grained asphalt mixtures for ACP32 base layers. The theoretical part deals with the availability of aggregates in the Czech Republic and also solves the issue of producing asphalt mixtures with a higher content of R-material. The theoretical part also compares the use of R-materials in the Czech Republic with other countries. The practical part deals with the design, production and testing of selected mixtures. To determine the properties of the mixtures, the rolling wheel tests, TSRST and the determination of the modulus of elasticity were selected.
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Dynamic viscosity of asphalt binders
Broďák, Marek ; Coufalík, Pavel (referee) ; Dašek, Ondřej (advisor)
The bachelor thesis describes a laboratory characteristics of bituminous binders. The principle, procedure of meansurment and comparison of test results of dynamic viscosity, needle penetration and softening point by ring and ball method will be described. The tests will be performed on samples of the bituminous binders with different degree of modification.
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