Browsing Ústav fyziky by Author "Dvořák, Richard"
Now showing items 1-8 of 8
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Acoustic non-destructive testing of high temperature degraded concrete with comparison of acoustic impedance
Dvořák, Richard; Chobola, Zdeněk; Kusák, Ivo (MATEC Web of Conferences, 2018-10-30)The paper is focused on non-destructive measurement of high temperature degraded concrete test specimens of three mixtures different by the use of coarse aggregate. Testing is done by ultrasonicpulse velocitymethod and ... -
Analysis of temperature degraded concrete at high temperature by applying of non-linear characteristics
Pazdera, Luboš; Topolář, Libor; Hoduláková, Michaela; Dvořák, Richard; Mikulášek, Karel (IOP Publishing, 2018-07-12)Concrete structures are commonly exposed to thermal loads as a result of the structure, ambient conditions, the heat of hydration, or exposure to fire. Therefore, there has been a growing interest in the research of advanced ... -
Classification of Thermally Degraded Concrete by Acoustic Resonance Method and Image Analysis via Machine Learning
Dvořák, Richard; Chobola, Zdeněk; Plšková, Iveta; Hela, Rudolf; Bodnárová, Lenka (MDPI, 2023-01-22)The study of the resistance of plain concrete to high temperatures is a current topic across the field of civil engineering diagnostics. It is a type of damage that affects all components in a complex way, and there are ... -
Correlating Hydration of Alkali-Activated Slag Modified by Organic Additives to the Evolution of Its Properties
Bílek, Vlastimil; Kalina, Lukáš; Dvořák, Richard; Novotný, Radoslav; Švec, Jiří; Másilko, Jiří; Šoukal, František (MDPI, 2023-02-25)This study investigates the relationships between the hydration kinetics of waterglass-activated slag and the development of its physical-mechanical properties, as well as its color change. To modify the calorimetric ... -
Decalcification resistance of various alkaliactivated materials
Hrubý, Petr; Bílek, Vlastimil; Topolář, Libor; Kalina, Lukáš; Marko, Michal; Šoukal, František; Dvořák, Richard; Herčík, Tomáš (IOP Publishing, 2021-09-29)The resistance of alkali-activated materials (AAMs) to degradation processes, particularly the decalcification, was studied in this paper. The ground granulated blast furnace slag was alkali-activated using various activators ... -
Efect of Chemical Aggressive Media on the Flexural Properties of Cured-In-Place Pipes Supported by Microstructure Observation and Acoustic Emission
Hodul, Jakub; Majerová, Jana; Drochytka, Rostislav; Dvořák, Richard; Topolář, Libor; Pazdera, Luboš (MDPI, 2020-07-08)The cured-in-place pipe (CIPP) method is currently the most frequently used approach for the renovation of piping without digging; this technology is suitable for pipes made from all types of material. The authors of this ... -
Effect of Hammer Type on Generated Mechanical Signals in Impact-Echo Testing
Dvořák, Richard; Topolář, Libor (MDPI, 2021-01-28)The impact-echo diagnostic method is a well-known nondestructive pulse compression test method, which can be relatively easily used for the testing of concrete and reinforced concrete elements. The evaluation of the ... -
Properties of concrete intended for further testing measured by the Impact-Echo and the ultrasonic pulse method
Karel, Ondřej; Dvořák, Richard; Rozsypalová, Iva; Schmid, Pavel (IOP Publishing, 2018-07-16)The aim of the paper is non-destructive measurement of differently degraded specimens by high temperature intended for further testing of joints of stainless steel helical reinforcement glued into the groove and differently ...