|
|
Non-destructive properties detection of concrete of prestressed beams
Mikulec, Jan ; Bílek, Vlastimil (referee) ; Cikrle, Petr (advisor)
The masers’s thesis is about the methods of non-destructive testing and about determining the properties of prestressed concrete. The first part pursues an introduction on the prestressed concrete, its essence and material properties. The next section describes the non-destructive diagnostic methods used in the practical part – the ultrasound impulse method, the resonance method and the rebound hardness test method. There are described destructive tests on the specimens for the calculation of the calibration. This is followed by a practical part, which describes the item tested - truss, its manufacturing, storage, and perform the test. Then search value are calculated from the test results and results are compared according to various procedures specified in the standards. The last section is devoted to the calculation of camber truss and loss of preload.
|
|
|
Methodology of historical bricks and masonry tests
Bartoň, Vojtěch ; Anton, Ondřej (referee) ; Cikrle, Petr (advisor)
This diploma thesis is focused on methodology for sorting of solid fired bricks for reconstruction of historical buildings. The theorethical part of this thesis includes description of production technology of solid fired bricks and diagnostic methods. In practical part there are these methods aplied on the solid fired bricks, which are intended for reconstruction of the bridge in Sedlec. There are monitored changes in structure of solid fired bricks caused by repeated freezing and defrosting. This changes are monitored by resonant frequency method and ultasonic pulse method.
|
|
| |
|
|
Experimental determination of the relationship between NDT parameters and the compressive strength of concrete
Kozáček, Vojtěch ; Komárková, Tereza (referee) ; Kocáb, Dalibor (advisor)
The diploma thesis deals with non-destructive testing of concrete as well as with the relationship between determined parameters and the compressive strength of concrete. The thesis is mainly focused on the ultrasonic pulse velocity method and the rebound hammer test. The experimental part of the thesis describes non-destructive tests performed on concrete blocks. The compressive strength was tested on the drill cores taken from the concrete blocks. The aim of this thesis is to find regression models of the relationship between the compressive strength and non-destructive parameters, and the subsequent analysis of the results.
|
|
| |
|
|
Comparison of calibration relationships for determining the compressive strength of various types concrete of non-destructive testing
Kaplan, Václav ; Voves, Jiří (referee) ; Brožovský, Jiří (advisor)
The bachelor thesis deals with the copmarison of calibration relationships for compressive strength of concrete by non-destructive testing. The work describes the methods for the determination of compressive strength of concrete obtained by non-destructive methods, including rebound hammer method, ultrasonic pulse method and combined SonReb method for various types of concrete. In thesis are described species tested concretes obtained normalweigt concrete, high-performance and high-strenght concrete, light-weight concrete and self-compacted concrete. In this work are described below used types of non-destructive testing, terms of use and czech technical standarts related with non-destructive testing. For the comparisons are utilized calibration relationships of technical standarts manufacturers of test equipment and specialised literature.
|
|
|
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.
|
|
|
Influence of transmission method on the results of measurement of refractory blocks by ultrasonic pulse method
Pospíšil, Dušan ; Dufka, Amos (referee) ; Brožovský, Jiří (advisor)
Ultrasonic pulse method is a non-destructive method, which is used in the construction industry to evaluate individual parameters of building structures. The aim of the thesis was to create the prerequisites for determining the rate of ultrasonic pulse propagation on refractory silica fittings and quartz glass fittings. Selected factors influencing the speed of ultrasonic pulse propagation in the tested samples were studied, namely the influence of the sounding direction, the influence of the natural frequency of the probes and the influence of the acoustic coupling material on the ultrasonic pulse method.
|
|
|
Testing of bricks intended for the repair of monuments
Lezová, Lívia ; Anton, Ondřej (referee) ; Cikrle, Petr (advisor)
The bachelor thesis is focused on methods of testing bricks, which will use to classify historic bricks into groups on usable, usable in extreme conditions, usable in limited extent and unusable for restoration of monuments or for construct new constructions. In the theoretical part, there is describe of historical development of solid fired bricks in Central Europe and an overview of methods for testing bricks, including a description of an accomplishments and their evaluation. In the practical part, there are methods applied to three visually different sets of bricks taken from 19th century construction.
|
|
|
Verification of the usability ultrasonic pulse method for the assessing of frost resistance of concrete bricks
Kašparová, Jana ; Hubáček, Adam (referee) ; Brožovský, Jiří (advisor)
Purpose of Bachelor thesis is to verify use of the utrasonic impulsive method to determine frost resistence of the concrete. Theoretical part disscusses about basic characteristic of a vibropressed concrete, description of a causes of frost and defrosting on the concrete. As well further factor simple menting frost resistance are reviewed. Summary is followed with standard requirements forwall concrete elements, trial proceduresfor non destructive and destructive methods for concrete and other construction materials and thein evaluation systems. Second part of Bachelor thesis is dedicated to analyse and evaluate results and relationship of trials used for testing of a concrete brick in frost resistence with use of cyclic freezing and use of a trial non destrucive ultrasonic impulsive method as well destructive mode.
|
guest ::
