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Diagnostic Methods Suitable for Monitoring of Drying Process of Brick Product
Sarvaš, Ondřej ; Sokolář, Radomír (referee) ; Nevřivová, Lenka (advisor)
This work deals with the study of diagnostic methods suitable for monitoring of the drying process of brick raw materials. Based on the extensive literature search, several parameters are selected, which are appropriate to monitoring during drying. In addition, a methodology for measuring these selected parameters is proposed. In the experimental part, the use of all described methods is gradually verified on the brick raw material with and without shortening additive (also known as grog). Was carried out: measurement of the surface temperature in the climatic chamber, determination of humidity distribution in the sample, determination of moisture diffusivity, determination of tensile strength, determination of ultrasonic wave velocity and determination of dynamic E-modulus of elasticity. Results of experiments and the gained experiences show, that at least two of the above-mentioned monitoring methods are very appropriate and beneficial – determination of moisture diffusivity and determination of tensile strength. In the work was described in detail the procedure of determination of moisture diffusivity of material. The dependence of moisture diffusivity on the moisture content of the dried material, has been described. Also, differences between raw material with grog and without grog has been described. As part of the practical verification of the experiment designed to determine the tensile strength at different humidity levels of test samples. A new shape of the test specimens and a new device were designed to allow them to be attached to a hydraulic press. The results of this work show that the tensile strength of the ceramic green bodies is primarily dependent on the moisture content of the material. The type of raw material almost does not affect the tensile strength.
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Vliv teploty lepidla a povrchu adherendu na hloubku penetrace lepidla do masivního dřeva
Voldřichová, Anna
The final thesis deals with the influence of different gluing conditions on the depth of penetration of the adhesive into the surface of solid wood, specifically of the influence of increased pressure during pressing. Furthermore, the thesis investigates the effect of penetration on the strength of the glued joint under tensile loading. Specimens of spruce and oak wood were glued with UF glue and PVAC glue, pressed under different compression pressures and then subjected to tensile test. SEM analysis on an electron microscope was used to evaluate the depth of penetration. The results of the investigation of the effect of ink on the strength of the bonded joint and the penetration depth of the adhesive into the material are also included. The ink was used in the adhesive mixtures for the purpose of colouring the bonded joint.
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Analýza vybraných vlastností lepených dřevěných kolíkových spojů
Linhart, Matěj
The thesis is aimed at the tensile strength of wooden dowel joint using different wood species of dowels, different types of adhesives and different material of carriers in which the dowels are glued and subsequently pulled out of them. The tensile strength of dowel joints is influenced by a several of factors which including the wood species of dowels, the type of adhesive and the material being joined. In this thesis a total of three wood species of dowels were compared (Robinia pseudoacacia L., Fagus sylvatica L., Carpinus betulus L.), two types of adhesives (PVAc adhesive Multibond SK-8 and PUR adhesive AG-PUR Standard) and two types of carrier material – insulation material Purenit and birch plywood. Both carrier materials were part of a glued spruce beam like a middle layer. A total of 12 variants of test samples were compared, which differed from each other in the wood species of dowel, adhesive type, and material of the carrier. The best results were achieved with test sample variants that contained birch plywood as a carrier and were glued with PUR adhesive AG-PUR Standard.
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Use of 3D printing technology in the automotive industry
Hyhlík, Pavel ; Šafl, Pavel (referee) ; Binar, Tomáš (advisor)
This thesis deals with 3D printing technology and its applicability to the automotive industry. It discusses the types of technology, the materials used for 3D printing, required software and the specific applications. One of the materials is selected and analyzed for its properties, after which spare parts are designed and manufactured from it. The thesis includes a case study looking at the economic viability of additive manufacturing for engineered parts.
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Influence of hydration accelerators on zinc - doped cement mortars
Beneš, Pavel ; Šilerová, Iva (referee) ; Šiler, Pavel (advisor)
This work deals with monitoring the hydration of cement mortars and cement pastes made from CEM I 42.5 R cement doped with zinc oxide in an amount of 1 % wt. To eliminate the delay in the onset of hydration due to the presence of zinc oxide, the following accelerators were added to the cement mixtures in different proportions: calcium oxide, formic acids and calcium formate. Hydration was monitored using isoperibolic calorimetry. Furthermore, the mechanical properties of mixtures were investigated, namely the tensile strength after bending and the compressive strength after 7 days and after 28 days. The cement mortars were further subjected to additional analyses, such as porosimetry, DTA/TG and SEM.
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Hodnocení kvality pomocí nedestruktivních technologií
Šarocký, Robert
This diploma thesis is focused on evaluating quality of materials which are manufactured by additive method of production. The thesis describes methods of additive production and their materials. Furthermore, the thesis deals with the methodology of investigation of mechanical properties of products of additive production. The following part of the thesis describes production of samples from two different types of material. Subsequently, these samples were tested by acoustic emission in the impact bending test and the tensile strength test.
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Welding of Al-Si coated high-strength steel 22MnB5
Šebestová, Hana ; Horník, Petr ; Mikmeková, Šárka ; Novotný, Jan ; Mrňa, Libor
Al-Si-based coatings are widely used as surface protection of steel sheets against high-temperature oxidation during the hot stamping process. Laser welding is a suitable technology for hardened components joining because it does not produce a wide heat-affected zone with a degraded microstructure. The highly concentrated energy of the laser beam is responsible for rapid heating and subsequent rapid cooling of material which results in insufficient homogenization of the weld metal. In Al-rich areas (Al originates from the coating), ferritic bands are formed in the dominantly martensitic matrix. These bands decrease the strength of laser weld by more than one third compared to the base metal. The low-power electric arc placed immediately behind the laser beam can help to achieve a slower cooling of the weld metal, reduce the ferritic bands and increase the strength of weld joints up to 90 % of base metal tensile strength.
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Cold asphalt mixtures
Spáčil, Petr ; Hýzl, Petr (referee) ; Dašek, Ondřej (advisor)
The bachelor thesis is divided into theoretical and practical part. The theoretical part consists of explanation of the problem. The thesis includes definitions as Bitumen, Asphalt Mixture, Asphalt Binder, Cut-back Bitumen and Viscosity. The practical part is focused mainly on the description of the test methods used on Asphalt Binders and Mixtures which were intended for repairs. It describes differences between used Asphalt Binders and explains and describes other used materials. The practical part compares the mixtures of different Cut-back Bitumen. It describes the production process and project of Cut-back bitumen mixture, the production process of individual test solids and compares the differences with hot made asphalt mixture. It also describes the analysis of volumetric, mechanical-physical and funcional tests in purpose of evaluating the differences between standard Cut-back Bitumen and new biofluxed asphalt binder.
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Study of FRP for concrete reinforcement
Blahová, Aneta ; Prokeš,, Jan (referee) ; Bodnárová, Lenka (advisor)
The diploma thesis aims to analyze bent FRP reinforcements. It describes the method of production of bent FRP reinforcement, examples of application of FRR reinforcement in structures and mentions aggressive influences influencing the durability of FRP reinforcement. Furthermore, an experiment is proposed to monitor changes in straight and bent FRP reinforcement stored in an aqueous environment at 20 °C and an alkaline environment at 20 °C and 40 °C. The output of the diploma thesis is the evaluation of changes in mechanical properties and durability. The condition of the FRP reinforcement is documented using optical and electron mocroscopy.
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