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Methodology for determining the durability of concrete and its resistance to frost and chemical deicing salts
Chaloupková, Kristýna ; Novosad, Petr (referee) ; Hubáček, Adam (advisor)
The bachelor's thesis explores the possibilities of improving testing procedures for determining the resistance of concrete to frost and chemical deicing salts. Currently used testing methods are notably problematic in terms of their repeatability and reproducibility. These tests are influenced by several factors, including the method of sample storage prior to testing, the preparation of the test surface, and the significant impact of edge effects. Additionally, the raw materials used in the test solution also affect the outcomes. During the test, water condensation occurs in the freezing chamber, altering the concentration and level of the test solution.
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The comparison of testing methods using for determining the frost resistance of concrete
Kněbort, David ; Vymazal, Tomáš (referee) ; Kocáb, Dalibor (advisor)
The diploma thesis deals with the possibilities of evaluating the degradation of mechanical resistance of non-air-entrained concrete in the structure by frost cycles. The first part is focused on concrete, its resistance and test methods. This is followed by the definition of frost resistance, the effects of freeze-thaw on concrete at all stages of its service life and the possibilities of determining freeze-thaw resistance according to current standards. It describes in more detail selected test methods for determining frost resistance. In the practical part, it focuses on the determination of degradation resistance of test specimens made in molds and taken from the structure using reference and non-reference methods. In conclusion, it compares the different test methods and their suitability for the determination of freeze-thaw resistance.
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Options of determining the frost resistance of concrete in a structure
Jindrová, Barbora ; Vymazal, Tomáš (referee) ; Kocáb, Dalibor (advisor)
The diploma thesis deals with different methods of determining levels of degradation of concrete due to freezing, also considering the options of freeze thaw resistance determination in structure. At first the properties of concrete and possible mechanisms of concrete degradation are described – mainly the effects of freezing water in the inner structure and of the combination of freezing water and de-icing chemicals on the surface. Principle and properties of air-entrained concrete are also mentioned. An overview of the approaches that current standards use to determine the freeze-thaw resistance of concrete is listed, followed by description of the tests that are used on air-entrained concrete specimens in the main part of the thesis. A portion of the test specimens was made in moulds while the rest was obtained from structure (concrete block). The non-destructive tests used are evaluated in several different ways and their results are compared with the destructive tests. Comparison and evaluation of different approaches used to determine the freeze-thaw resistence of concrete are the main outcome of this thesis.
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Methods of assessing the durability of concrete against frost and chemical deicing salts in the Czech Republic and in Europe
Žíla, František ; Novosad,, Petr (referee) ; Hubáček, Adam (advisor)
The bachelor thesis deals with the methods of assessing the durability of concretes against frost and chemical deicing salts used in the Czech Republic and Europe. The theoretical part of the thesis describes the basic properties of concrete, the classes of environmental influence, the theory of concrete failure by cyclic freezing and thawing, methods for assessing the durability of concrete against freezing and methods for assessing the durability against water and chemical deicing salts, as well as properties affecting the repeatability and reproducibility of tests. The practical part focuses on testing the resistance of concrete to the action of freezing and chemical thawing agents using the methods according to the standards ČSN 73 1322 and ČSN 73 1326 and also on the influence of concrete surface treatment on the process and result of these tests.
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The comparison of testing methods using for determining the frost resistance of concrete
Kněbort, David ; Vymazal, Tomáš (referee) ; Kocáb, Dalibor (advisor)
The diploma thesis deals with the possibilities of evaluating the degradation of mechanical resistance of non-air-entrained concrete in the structure by frost cycles. The first part is focused on concrete, its resistance and test methods. This is followed by the definition of frost resistance, the effects of freeze-thaw on concrete at all stages of its service life and the possibilities of determining freeze-thaw resistance according to current standards. It describes in more detail selected test methods for determining frost resistance. In the practical part, it focuses on the determination of degradation resistance of test specimens made in molds and taken from the structure using reference and non-reference methods. In conclusion, it compares the different test methods and their suitability for the determination of freeze-thaw resistance.
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Options of determining the frost resistance of concrete in a structure
Jindrová, Barbora ; Vymazal, Tomáš (referee) ; Kocáb, Dalibor (advisor)
The diploma thesis deals with different methods of determining levels of degradation of concrete due to freezing, also considering the options of freeze thaw resistance determination in structure. At first the properties of concrete and possible mechanisms of concrete degradation are described – mainly the effects of freezing water in the inner structure and of the combination of freezing water and de-icing chemicals on the surface. Principle and properties of air-entrained concrete are also mentioned. An overview of the approaches that current standards use to determine the freeze-thaw resistance of concrete is listed, followed by description of the tests that are used on air-entrained concrete specimens in the main part of the thesis. A portion of the test specimens was made in moulds while the rest was obtained from structure (concrete block). The non-destructive tests used are evaluated in several different ways and their results are compared with the destructive tests. Comparison and evaluation of different approaches used to determine the freeze-thaw resistence of concrete are the main outcome of this thesis.
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