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Comparison of selected parameters of tensile strength of concrete
Rozsypalová, Iva ; Žítt, Petr (referee) ; Daněk, Petr (advisor)
The thesis deals with a comparison of the selected strength tension properties of the hardened concrete and finding relationships between them. This is essentially a simple tensile strength, tensile flexural strength and tensile splitting strength. The text describe the testing procedures to determine the tensile strength of concrete. Furthermore, there are presented the results of testing on different types of concrete (plain concrete, lightweight concrete, steel-fiber concrete, polymer-fibre concrete and high strength concrete). The conclusion deals with the derivation of dependancy between concrete strengths and comparing the values obtained from the available relations with the results of the tests.
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Properties of reinforcing glass-fiber geogrids
Veselý, Petr ; Šperka, Pavel (referee) ; Dašek, Ondřej (advisor)
A proper road infrastructure is an essential part of today’s economy. Usage of roadways should be safe and its flow should be easy going. Primary net of roadways is already in place and attention shifts to its maintenance. Because of constantly increasing loads of heavy traffic, roadways are degrading at a faster pace, while there are still smaller time windows and less avialable resources for their reconstruction. That is why there has been rising demand for pavements that last longer and are able to carry higher weights. With respect to the rural roads it becomes obvious because of low amount of resources for their maintenance, that it is necessary to find an effective way to enhance pavements. From the foregoing it can be safe to say, that there is a clear need for reliable, durable and cost-effective technology of maintenance, such as the use of grids in asphalt pavements. This thesis deals with properties of geogrids made of glass fiber after its compaction as well as its effects on reduction or elimination of spreading of cracks in pavements.
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Waste building material to subgrade pavement
Masař, Daniel ; Hýzl, Petr (referee) ; Stehlík, Dušan (advisor)
The theoretical part of the diploma thesis searches the production of Construction and demolition waste and their subsequent transformation into the final recyclate and its possible use in roads. Attention is focused on the use of mixed recycled material into subgrade of the pavement and the characteristics of tests that must be performed before its used to the road. The next chapters pai attention to the problematic properties of recyclates, foreign experience with the use of mixed recyclate in Construction and the possibilities of its development. The practical part verifies the suitability of mixed recycled material into subgrade of the pavement using laboratory tests. The tests are performer on individual mixtures of mixed recycled material with cement, blast furnace slag or cement dust in various percentages. The results are then compared and it is evaluated which mixtures show the best properties. Part of the practical part is also the economic evaluation of these mixtures against commonly used materials.
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Monitoring the Influence of ceramic bond on the properties of insulating refractory materials
Friček, Jakub ; Kovář,, Pavel (referee) ; Nevřivová, Lenka (advisor)
Thermal insulating refractories are an integral part of each thermal unit since they reduce its energy consumption. The current phenomenon of saving in both environmental and financial aspects reflects in searching for such possibilities to produce at lower manufacturing and material costs. One of the possible ways is to valorise waste materials. The theoretical part then deals with the division of refractory materials, classification of thermal insulation refractory materials and manufacturing technologies. The experiment is focused on the production of insulating refractory materials made from plastic dough with a possibility of using sawdust and materials made by pressing mixture moist, with a focus on coal bottom ash. Both of these technologies will be tested for the possibility of modification by using mixed clays and of increasing the strength by using clays with lower sintering temperature.
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Study of properties of cementitious composites with fiber reinforcement from inorganic fibers
Gottwaldová, Aneta ; Novosad, Petr (referee) ; Bodnárová, Lenka (advisor)
Diploma thesis deals with study of properties of cementious composites with fiber reinforcement from glass and basalt inorganic fibers. Diploma thesis includes a theoretical and experimental part. The theoretical part deals with information about glass and basalt fibers, their durability and usage. In the experimental part we monitored properfies of cement composites with basalt and glass fibers. Fibers were exposed to an aggressive environment. The properties of composites with reference fibers were compared with composites with fibers affacted by the aggressive environment. The properties of composites were examined after 28 and 90 days. We monitored compresive strenght, bending tensile strenght, tensile strenght, surface layer strenght and SEM.
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The effect of moisture on the surface strength of sandstone rock outcrops
Fraňková, Kateřina-Alexandra ; Weiss, Tomáš (advisor) ; Bruthans, Jiří (referee)
The aim of the thesis is to evaluate the influence of moisture on the tensile strength of sandstone rock outcrops and also to evaluate the possible influence of man on the erosion of sandstone rocks, especially by climbing activities, by means of a research study and specific examples from my own and non-own researches. Just a few studies have so far addressed the effect of moisture on the tensile strength of sandstone, and although the results of these studies generally suggest that the tensile strength of sandstone rock outcrops decreases with increasing moisture, there are differences depending on the specifics of the selected study areas. It would therefore be interesting to do a study that names and evaluates the possible aspects influencing this dependence. In my thesis I have evaluated studies carried out using different methodologies, which are described in a separate chapter. The results of the studies show that the tensile strength does indeed decrease with increasing moisture content, but the degree of decrease depends mainly on the mineralogical composition of the rock. The tensile strength of rocks with a high clay or organic content will decrease significantly more with increasing moisture than the tensile strength of rocks with a high quartz content. I have also reviewed several...
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Waste building material to subgrade pavement
Masař, Daniel ; Hýzl, Petr (referee) ; Stehlík, Dušan (advisor)
The theoretical part of the diploma thesis searches the production of Construction and demolition waste and their subsequent transformation into the final recyclate and its possible use in roads. Attention is focused on the use of mixed recycled material into subgrade of the pavement and the characteristics of tests that must be performed before its used to the road. The next chapters pai attention to the problematic properties of recyclates, foreign experience with the use of mixed recyclate in Construction and the possibilities of its development. The practical part verifies the suitability of mixed recycled material into subgrade of the pavement using laboratory tests. The tests are performer on individual mixtures of mixed recycled material with cement, blast furnace slag or cement dust in various percentages. The results are then compared and it is evaluated which mixtures show the best properties. Part of the practical part is also the economic evaluation of these mixtures against commonly used materials.
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Study of properties of cementitious composites with fiber reinforcement from inorganic fibers
Gottwaldová, Aneta ; Novosad, Petr (referee) ; Bodnárová, Lenka (advisor)
Diploma thesis deals with study of properties of cementious composites with fiber reinforcement from glass and basalt inorganic fibers. Diploma thesis includes a theoretical and experimental part. The theoretical part deals with information about glass and basalt fibers, their durability and usage. In the experimental part we monitored properfies of cement composites with basalt and glass fibers. Fibers were exposed to an aggressive environment. The properties of composites with reference fibers were compared with composites with fibers affacted by the aggressive environment. The properties of composites were examined after 28 and 90 days. We monitored compresive strenght, bending tensile strenght, tensile strenght, surface layer strenght and SEM.
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Properties of reinforcing glass-fiber geogrids
Veselý, Petr ; Šperka, Pavel (referee) ; Dašek, Ondřej (advisor)
A proper road infrastructure is an essential part of today’s economy. Usage of roadways should be safe and its flow should be easy going. Primary net of roadways is already in place and attention shifts to its maintenance. Because of constantly increasing loads of heavy traffic, roadways are degrading at a faster pace, while there are still smaller time windows and less avialable resources for their reconstruction. That is why there has been rising demand for pavements that last longer and are able to carry higher weights. With respect to the rural roads it becomes obvious because of low amount of resources for their maintenance, that it is necessary to find an effective way to enhance pavements. From the foregoing it can be safe to say, that there is a clear need for reliable, durable and cost-effective technology of maintenance, such as the use of grids in asphalt pavements. This thesis deals with properties of geogrids made of glass fiber after its compaction as well as its effects on reduction or elimination of spreading of cracks in pavements.
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Monitoring the Influence of ceramic bond on the properties of insulating refractory materials
Friček, Jakub ; Kovář,, Pavel (referee) ; Nevřivová, Lenka (advisor)
Thermal insulating refractories are an integral part of each thermal unit since they reduce its energy consumption. The current phenomenon of saving in both environmental and financial aspects reflects in searching for such possibilities to produce at lower manufacturing and material costs. One of the possible ways is to valorise waste materials. The theoretical part then deals with the division of refractory materials, classification of thermal insulation refractory materials and manufacturing technologies. The experiment is focused on the production of insulating refractory materials made from plastic dough with a possibility of using sawdust and materials made by pressing mixture moist, with a focus on coal bottom ash. Both of these technologies will be tested for the possibility of modification by using mixed clays and of increasing the strength by using clays with lower sintering temperature.
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