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Bio-based wood adhesive derived from brewers spent grain
Muselíková, Vladislava
Brewers spent grain (BSG) is an abundant waste material from the brewing process, representing approximately 85% of total by-products generated, is rich in cellulose and non-cellulosic polysaccharides and has a strong potential to be recycled. One of the main components of the BSG is protein, which has a potential to be extracted, modified and used as an adhesive for the woodworking adhesive. This work deals with the protein extraction through alkali treatment and its subsequent modification, crosslinking with glyoxal. The crosslinked adhesive was tested through ABES method to find, that ideal content of glyoxal is 20%. Subsequent adjusted standard tests for the lap shear strength and bend strength (MOE and MOR values) were used to compare its values to commercially available PVAc adhesive. The lap shear strength results were 2,7 times lower to PVAc, the bend strength values were, on the other hand, 1,5 times higher. The PVAc was partially replaced (50 and 25%) by the protein adhesive showing that the extracted adhesive could serve as a partial replacement to lower the ecological impact of the PVAc adhesive.
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Přírodní lepidla na bázi krve - pevnost lepeného spoje u rostlého dřeva
Pluháček, Viktor
This bachelor thesis is an experiment with a focus on the use of adhesives from natural and renewable sources. Adhesives used are Henkel's PVAc glue, Ponal Super 3 and the blend of bovine blood, slaked lime, bile and milk. Two types of test specimens were made from spruce and beech boards. One type tested for shear strength and the other for tensile strength perpendicular to the adhesive joint. Part of the samples were subsequently conditioned and the other tested by soaking in water to determine the durability class according to EN 204: 2001. After being removed from the water, soaked samples were conditioned. Followed by their testing.
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Využití alternativních výztužných materiálů ve vrstvených lepených materiálech
Svatoň, Kryštof
Thesis deals with possibilities of reinforcement of plywood boards with natural materials in order to improve mechanical and physical properties. 5-layer spruce boards were reinforced under top layer with basalt fabric and jute. There was used environmental friendly glue for plywood fabrication. Results indicate increase in mechanical properties of boards with basalt fabric reinforcement. Mechanical properties of boards reinforced by jute were decreased.
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Pevnostní vlastnosti lepidlových filmů v závislosti na klimatických podmínkách lepených spojů
Knápková, Adéla
The diploma thesis deals with influence of climatic conditions on the strength properties of adhesive bonded joints of outdoor wood furniture by using dispersion-based PVAc adhesive for assembly joints. Samples of acacia, beech and larch wood were glued with waterborne polyvinyl acetate adhesive. The glued joints were exposed to various humidity and temperature conditions in order to monitor the influence of climatic conditions on the shear tensile strength of adhesive film of individual wood species.
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Study of properties of polymer-modified cementitious adhesive material during shear stresses
Powetz, Dominik ; Nováček,, Jaroslav (referee) ; Žižková, Nikol (advisor)
This bachelor thesis deals with the study of the properties of the polymer modified cementitious tile adhesives during shear stress. In the theoretical part of this thesis is described the influence of absorption of the tile and the content of polymer powder on tensile adhesion and shear strength. After that, the review of known methods for determining the shear strength of adhesives and mortars was done. In the last step of the theoretical part, this bachelor thesis is focused on the most common building defects and failures that occur during the tiling and their subsequent use in the construction of wall cladding elements and ceramic floor tiles. The practical part of the bachelor thesis is focused on the design and testing of an alternative method for the determination of shear strength of bonding, with the effort to achieve the simplest and the most economical option for testing (easy sample preparation, low demands on instrumentation) with the possibility of replacing the known method DIN 18156-3 for testing shear strength of cementitious tile adhesives.
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New directions for waterproofing of underground transport
Čech, Tomáš ; Čížek, Luboš (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.
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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.
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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.
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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.
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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).
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