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Study of the dependence of concrete composition on the values of elasticity modules
Křížová, Klára ; Kolář,, Karel (referee) ; Adámek, Jiří (referee) ; Ďurica,, Tibor (referee) ; Hela, Rudolf (advisor)
The modulus of elasticity is one of the basic characteristics of concrete defining elastic deformation of concrete and it plays a significant role in the static design of structures. Due to current trends in concrete technology, offering a wide variability in the proposals of the composition of concrete, there are changes not only in strength characteristics but also in the modulus of elasticity of concrete. The aim of this doctoral thesis is to study the dependence of different compositions on modulus of elasticity of concrete. Design of concrete composition is prepared with respect to the use of different types of cement, mineral admixtures, types and fractions of aggregates. The work is mainly focused on the determination of static modulus of elasticity in compression with the addition of dynamic modules. In the first phase determined modulus of elasticity are compared with tabulated values according to Eurocode 2, which are derived for the specific strength class of concrete. Part of this work is the compilation of the main technological aspects of concrete which can favorably affect the modulus of elasticity.
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Influence of dispersed reinforcement on the physico-mechanical properties of the resulting composite
Láník, Jaromír ; Adámek, Jiří (referee) ; Kolář,, Karel (referee) ; Doc.Ing. Karel Kubečka, Ph.D (referee) ; Schmid, Pavel (advisor)
The dissertation is focused on the issue of implementation and evaluation of the laboratory tests fiber reinforced concrete. The issue of steel fiber is solved in terms of their physico-mechanical parameters, which are an important part of their design and reliable operation in the product design. The experimental part of the thesis is focused on laboratory tests of steel fiber of different strength classes and different weight benefits of steel fibers, the default reference mixture of plain concrete are certified mixtures commonly used as structural concrete in construction. The evaluation of the testing of samples produced steel fiber is made by three selected recommending regulations for the design and testing of structural steel fiber. In conclusion, the individual obtained experimental results are compared.
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The model of direct payments in e-commerce
Adámek, Jiří ; Fremelová,, Andrea (referee) ; Dvořák, Jiří (advisor)
The thesis aim is to describe the issue of direct payments in e-commerce both for the Czech national region and international purposes. The most common payment methods are compared from technical and functional point of view. Based on up-to-date e-commerce trends the thesis designs an optimal direct payments processing model for a small company. The main criterion is the highest price-performance ratio. With slight changes the designed solution can subsequently be fitted to other companies.
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Creating conditions for evaluation of high-strength concrete characteristics using non-destructive testing methods
Procházka, David ; Horký,, Ondřej (referee) ; Kolář,, Karel (referee) ; Adámek, Jiří (referee) ; Brožovský, Jiří (advisor)
High-strength concrete (HSC) belongs in the recent years to frequently used types of concrete. It allows realization of static challenging structures and also shows due to its dense structure greater durability especially against aggressive media. Currently HSC construction realization abroad is not exceptional. It’s using in the Czech Republic is still limited. When realized, then in a small scale in civil engineering works. The realization of high-strength concrete structures is closely related with the concrete construction quality verification. Good efficiency of the quality control methods can provide non-destructive testing methods (NDT), especially when investigating strength of concrete built in structure. A lack on relevant data for non-destructive testing of HSC in technical and normative rules is to be considered as a significant deficiency. Evident for HSC generally is the lack in literature on deeper analysis of the factors affecting their non-destructive testing, as well a meaningful methodology or practically usable calibration relationships. HSC differs from ordinary concrete not only by used components, but also by more compact structure with different strength – elastic characteristics. Considering these differences, HSC strength prediction can not be performed by using calibration relationships developed for ordinary concrete. Moreover, the question is to what extent the current knowledge of the NDT results influencing factors can be considered as valid. The paper presents findings on the effects of the key factors affecting the measurement results of Schmidt hardness method and ultrasonic pulse method, including recommendations for the practical application of these methods. The problematic of static vs. dynamic modulus of elasticity was also solved. Calibration equations for predicting the compressive strength of HSC from the non-destructive testing parameter were elaborated, showing high cohesion among variables and practically usability.
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ASPECTS APPRAISEMENT LAW BUILDING
Adámek, Jiří ; Scholzová, Vlasta (referee) ; Telec, Ivo (referee) ; Weigel, Lubomír (advisor)
Dissertation work deals problems Law Of Building in relations to new Civil Code No. 89/2012 Sb. (NOZ - new Civil Code) Legal regulations are for all new and rather are in common level. Supplying present, more than 40 years old Civil Code new recipe, presents revolutionary changes in civil right. NCC starting from the another ideological, political and terminological bases. With new Civil Code loom incomming new questions: What will real property and what will no. What kind of law is possible newly to real property to establish. How will new property owners limited. Important is appreciate, that by the new Civil Code was cancelled current Civil Code, so and current Business Code too. New legal regulations cancelles more than 238 law regulations. All the law, which affected law relations to real property are cancelled. Contribution is solving the problems and summaries the cases, where would had Building Law to do. Result of the dissertation work is:
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Structural Properties of Ultralight Concrete and its Optimal Application in Structures
Kadlec, Jaroslav ; Bílek,, Vlastimil (referee) ; Adámek, Jiří (referee) ; Terzijski, Ivailo (advisor)
This doctoral thesis deals with design of three variants of ultra lightweight concrete (ULC) and their mechanical properties. The ULC usually has the dry density of 900-1200 kg/m3 and it is possible to use it for load bearing structures. Low density of ULC is achieved by replacing heavy aggregate for lightweight aggregate. The lightweight aggregate is known under the trade name Liapor in the Czech Republic. To achieve density below 1000 kg/m3, an aeration of the paste has to be done. An exchange of heavy aggregate for lightweight aggregate results in a very fragile behavior of ULC. A great attention is paid to bond strength between concrete and reinforcing steel in the thesis. In addition to the standard test of bond strength testing by pull-out, a modified pull-out test is designed, which includes the effect of minimum reinforcement cover. The mentioned test more precisely simulates a real behaviour of the structure exposed to bending moment. The doctoral thesis tries to point out on different parameters between measured data and the applicable standard for the design of load-bearing structures.
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E-government in Business
Adámek, Jiří ; Langer, František (referee) ; Dvořák, Jiří (advisor)
The goal of the thesis is to analyse the issue of e-government in the Czech republic and its impact on private sector. It both describes the current situation and searches for new opportunities to enhance and modify the system. Based on the performed analyses the thesis designs a suitable way to benefit from e-goverment utilization within the company.
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Analysis of measurement results of concrete permeability for air and water as a basis for estimating the actual durability
Kadlecová, Zlata ; Kolář, Karel (referee) ; Pavlík,, Vladimír (referee) ; Adámek, Jiří (referee) ; Anton, Ondřej (advisor)
Permeability surface layer of concrete is engaged in many research institutes around the world, because the surface layer is the weakest link in the entire concrete structure. This dissertation followed on the issue of global solutions and broadens the horizon of the covercrete issues. The aim of this work was to create the conversion relations between the methods for evaluating the permeability of concrete surface layer allow approximate evaluation of the surface layer of concrete depending on the current moisture. In practice mostly occur concrete, which surface mass of moisture is equal to 3 %, so this amount of moisture is selected as the reference. For comparison were used: the device TPT (Torrent Permeability Tester), device GWT (Germanns Water Permeability Tester) and methods ISAT (Initial Surface Absorption Test). A secondary aim was to create a unified methodology for measuring the device.
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Analysis of the effect of insulation on the housing unit price in a non-standard house in Brno
Hájek, Petr ; Hlavinková, Vítězslava (referee) ; Adámek, Jiří (advisor)
Assessing the impact of insulation on the price of immovable assets and return on such an investment. The work is based price of the thermal insulation on the specific model of the object and the subsequent conversion of prices on selected housing unit. Housing unit is also measured using current valuation rules, as well as by market valuation. Create Database insulated and non-insulated housing units and the difference between their prices is determined by the value of work compared with the cost model chosen insulation unit. Subsequently, the price is compared to the insulation housing units with insulation effect on the market price of the apartment. The paper assessed the state of energy consumption before and after the insulation work. The work is conceived as a breakdown of theoretical information, which are then practically applied to the object model. Calculations are therefore linked with the text part of the thesis.
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