|
|
New directions for waterproofing of underground transport
Čech, Tomáš ; Vaněrek, Jan (referee) ; Šťastník, Stanislav (advisor)
This diploma thesis focuses on the implementation of waterproofing of underground constructions using an LLDPE membrane hinged on anchors. In the future, this method will replace the commonly used waterproofing system in Scandinavia with extruded polyethylene foam. This method of tunnel construction and waterproofing is compared with the NRTM method, often used in Central Europe. The thesis describes the installation of a waterproofing system, especially materials, accessories, welding devices and auxiliary installation equipment. The main focus of the thesis is to verify the reliability of the individual types of welds and to assess the waterproofing system in terms of implementation and environmental demands.
|
|
|
Asphalt layers with reinforcing glass-fiber geogrids
Sachr, Jiří ; Bohuš,, Štěpán (referee) ; Dašek, Ondřej (advisor)
This diploma thesis deals with the use of glass fiber geogrids and geocomposites in road construction. The reinforcement elements are inserted between the wearing and binder asphalt layer. This diploma thesis summarizes the knowledge connected with reinforcing of asphalt roads using glass fiber. It examines the effect of reinforcing fiberglass elements on the resistance of asphalt layers loaded with traffic. At the same time, it deals with the application of a various amount of tack coat and subsequent behavior of the asphalt layers. In this work, laboratory tests of bond strength between layers on cores and four-point bending were performed.
|
|
|
Bonding in the automotive industry
Krejčí, Adam ; Hanáčková, Pavla (referee) ; Kubíček, Jaroslav (advisor)
The thesis presents a literature study of adhesive bonding technology. The work deals with the advantages and disadvantages of adhesive bonding, design of adhesive joints, technological processes of adhesive bonding and the division of adhesives. The thesis also discusses various materials used for the construction of car bodywork and their properties. The main focus of the work is on the use of adhesive bonding in the car industry, comparing traditional and modern technology used for the construction of bus bodywork. In the experimental part of the thesis, the aim is to reveal the influence of surface treatment on the resulting shear strength when employing metal to metal bonding.
|
|
|
Posouzení kvality lepení kombinovaných masivních materiálů na bázi dřeva
Ženatý, Petr
The idea of this work came from doc. Dr. Ing Pavel Král when some company contant him regarding research for using appropriate materials and adhesives for window frames. The goal of my work is to determine the bonding strength of various combinations of wood (oak, beech, larch, spruce, poplar and accoya) and polyurethane adhesives. The research was half focused on today less known tree species Accoya wood and its behavior in combination with other tree species. It is a modified type of wood (pine Radiata Pine), who thanks to a chemical process called acetylation becomes a high quality, durable and durable material. The practical part is a tensile stress test specimen to shear with various types of adhesives. My job was to find the right combination of wood and glue, that will have sufficient strength and concurrently resist external conditions (humidity, wind, solar radiation).
|
|
|
Lepení spojů zahradního dřevěného nábytku
Knápková, Adéla
Bachelor thesis deals with the influence of humidity on the strength of glued joints of wooden garden furniture by using a mounting adhesive. The joints of solid wood-samples of robinia and spruce were glued with one-component polyurethane adhesive. The bonded joints were exposed to the different humidity at elevated temperature and then it was compared to the strength and resistance between individual woods. Samples were strained on tensile shear strength test.
|
|
|
Factors affecting the properties of glued joints for glues used in the wood industry
Boška, Pavel ; Böhm, Martin (advisor)
Dissertation focuses on the influence of selected factors on the properties of the bond glued by acetate polyvinyl adhesives. Factors such temperature and moisture content of the environment, the pressing pressure and cyclic stress. Despite the same type of adhesive, the properties may vary for different producers of adhesives and according to which the product is not intended. Influence will be compared to the test samples of dried beech timber with regard to shear bond strength. They will be compared properties of adhesives from different manufacturers and different destination. Test samples and test progress carried out in accordance with current standards, or largely based on. This research should help users streamline the process of adhesive bonding and reduce the production costs of the bond.
|
|
|
Evaluation of load-deformation characteristics of glued timber using DIC analysis
Šot, Michal ; Vejpustek,, Zdeněk (referee) ; Vaněrek, Jan (advisor)
The work deals with issues of evaluation of the shear properties of timber structural materials, particularly CLT elements. The work contains an overview of extensive research so far presented scientific studies dealing with the characteristic shear properties of wood. In the practical part was carried out the experiment dealing with the failure mode of transverse lamellae of CLT elements that were exposed to shear stress. There were observed individual effects that this may affect the material properties. In the first part of the experiment were performed numerical models using FEM. In the second part, the test specimens were tested in three point bending. Here, attention was paid to the influence of macroscopic properties of wood on the distribution of stress cracks and shear strength, the tests were recorded using DIC system.
|
|
|
Effect of Interlayer Composition on Bond Strength between FRC Framework and Composite Veneer
Ibarra, Jonatanh José ; Pavelka,, Vladimír (referee) ; Poláček, Petr (advisor)
Hlavním cílem této práce je studium aktuálního problému adheze mezi kompozitními materiály, a určení vlivu složení mezivrstvy v pevnosti adhezivního spoje mezi vláknové (FRC) a částicové (PFC) kompozity, používané ve stomatologii. FRC tyčinky byly vytvořené na bázi komerční dimetakrylatové pryskyřice a skleněných S vláken. PFC byl vytvořen ze směsi pryskyřic (bis-GMA a PEGDMA), plněných drceným barnatým sklem. Celkově bylo připraveno a vyzkoušeno 84 vzorků. Vzorky byly rozdělené do pěti hlavních skupin. První skupina byla vytvořena ze série vzorků bez mezivrstvy. Zbylé čtyři skupiny byly rozděleny dle složení mezivrstvy (tloušťky a druhu pryskyřic). Částicové kompozity vzorků se lišily obsahem plniva (0, 10, 40 hm %). FRC tyčinky byly stejné pro všechny vzorky. Univerzální testovací přístroj ZWICK Z010 byl použit k zjištění smykové pevnosti adhezivního spoje všech vzorků. Rastrovací elektronový mikroskop byl použít k pozorování místa porušení. Ze získaných výsledků vyplívá, že s přidáváním mezivrstvy mezi vláknovým a částicovým narůstá smyková pevnost spoje. Důležitost těchto výsledků je způsobená tím, že v posledních letech použití těchto materiálů ve stomatologii narůstá a adheze zůstává jeden z hlavních problémů při klinické praxi.
|
|
|
Experimental comparison of shear properties of FRP measured by ASTM methods
Ponížil, Tomáš ; Mališ, Michal (referee) ; Urík, Tomáš (advisor)
Přesné určení konstitutivních smykových závislostí napětí na deformacích je základem pro pochopení chování anizotropního kompozitního materiálu. Bylo vyvinuto mnoho zkoušek smykových vlastností kompozitních materiálu. Jelikož vyvolání čisté smykové napjatosti je složité, tento stav je vyvolán pouze některými z nich. V této práci je ověřeno použití systému Aramis k vyhodnocení průběhu smykového přetvoření a následnému výpočtu konstitutivních smykových vlastností při provedení jednoduché zkoušky ohybem krátkého nosníku. Tyto výsledky jsou dále porovnány se zkouškou podle Nicolae Iosipesca.
|
|
| |
guest ::
