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Comparison of selected parameters of tensile strength of concrete
Rozsypalová, Iva ; Žítt, Petr (referee) ; Daněk, Petr (advisor)
The thesis deals with a comparison of the selected strength tension properties of the hardened concrete and finding relationships between them. This is essentially a simple tensile strength, tensile flexural strength and tensile splitting strength. The text describe the testing procedures to determine the tensile strength of concrete. Furthermore, there are presented the results of testing on different types of concrete (plain concrete, lightweight concrete, steel-fiber concrete, polymer-fibre concrete and high strength concrete). The conclusion deals with the derivation of dependancy between concrete strengths and comparing the values obtained from the available relations with the results of the tests.
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Properties of Fiber Reinforced Plastics
Jastrzembská, Alena ; Petránek, Vít (referee) ; Bodnárová, Lenka (advisor)
This thesis deals with the theoretical part of raw materials, production and properties of composite materials with fiber reinforcement and polymer matrix. It also gives a brief overview of selected prominent Czech and foreign producers of composite materials with polymer matrix and fiber reinforcement. The practical section deals with testing the durability of selected composite profiles immersion in aggressive environments and testing of compressive strength.
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Cement composite materials with polypropylene fibers
Preisner, Martin ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
This thesis deals with summarizing the possible effects of the addition of polypropylene fibers, especially low temperature plasma treated on the properties of cement composites and concrete. They are given basic information and distribution of polypropylene fibers. It describes the finish polypropylene fiber low-temperature plasma. The experimental part focuses on the effect of dispersion of polypropylene fibers treated plasma in the cement matrix.
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Modification of silicate materials for floors
Šlechtický, Luboš ; Ing. Miroslav Šťenko, Ph.D., LB Cemix (referee) ; Šťastník, Stanislav (advisor)
The thesis is devoted to the issue of flooring materials, cement and plaster. In the first part are discussed general properties and general requirements for flooring, as well as presents the most important properties of selected flooring materials. The work is dedicated to the modulus of elasticity, adhesion to the substrate and strength parameters of the tested materials. It also evaluates the effects of redispersible polymer powders in silicate compositions intended for floors.
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Properties, Testing and use of UHPC in Structures
Myšičková, Lucie ; Kocáb, Dalibor (referee) ; Cikrle, Petr (advisor)
Thesis describes properties and composition of UHPC compared to concretes of normal and high strength. It gives examples of already completed structures made of UHPC. The experimental part describes the optimization of concrete mix and production of specimens. In the end results of testing the properties of the developed mix from tests of dynamic and static modulus of elasticity, compressive strength and tensile strength by bending are described.
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ultra-high-strength concretes
Ambruz, Pavel ; Hubáček,, Adam (referee) ; Hela, Rudolf (advisor)
Thesis deals with summarizing knowledge about production methods of ultra – high – strength concrete (UHSC) and their possible use in practice, which is documented on the existing building. Further work shows suitable raw materials for production UHSC and their availability on the Czech market. The practical part results an experiment whose outcome should be concrete with a compressive strength of 150 MPa.
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The use of ultrasonic methods in the diagnosis of concrete structures
Stanislav, Štěpán ; Anton,, Ondřej (referee) ; Cikrle, Petr (advisor)
This Bachelor’s thesis is focused on presenting of a listing of testing procedures of concrete structures by means of an ultrasonic diagnostic method. It deals with the principles of the aforementioned method, possibilities of its use and with the procedures of testing pursuant to a various regulations. The purpose of the practical part of the thesis work, in which was undertaken the process of measurement on the model of concrete structure is to determine certain material characteristics of the concrete as well as the comparison of the direct, indirect and semi-direct transmission.
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Influence of Initial Conditions on the Modulus of Elasticity of Concrete for Bridges
Blažek, Michal ; Bílek,, Vlastimil (referee) ; Cikrle, Petr (advisor)
Beside the compressive strength of concrete, which is considered as the basic parameter parameter for design of concrete structures a modulus of the concrete elasticity should be set as well. This thesis deals with influences, which are acting on the concrete, particularly within the initial stage of its hardening (i.e. within 28 days after casting). Nowadays, when time is the most valuable factor, some knowledge is required about mechanical properties of concrete earlier than after above mentioned 28 days and to apply them advantageously. The concrete in initial stage of hardening is influenced by many factors that affect progress of the elasticity modulus during the course of the time. For understanding of these problems a literature search was performed, as well as the experiment demonstrating the effect of temperature on the modulus of the concrete elasticity. The effect of temperature on the modulus of elasticity of concrete in initial stage of hardening has not been intensively studied yet. Therefore, more attention is paid to it by this elaborate. The experiment investigated the static and dynamic elastic modulus of concrete, whose recipe is similar to one used for production of prefabricated and prestressed bridge girders.
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