National Repository of Grey Literature 8 records found  Search took 0.01 seconds. 
Effect of active ingredients, and their dosing to CHRL 28,90 days of age
Kodešová, Monika ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
Subject of this work is to design a batch of concrete with additives, which are to replace the cement of various doses so as to not adversely affect the properties of fresh and hardened concrete and simultaneously withstand the environment XF.
Optimization of the concrete composition with the use of recycled concrete aggregates
Skriňáková, Eva ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
Concrete as a building material is subject to continuous innovation and thanks to advanced technology and quantum of research, its properties are still improved. It is logical that the more concrete we produce, the more waste it arises. The volume of this waste can not be stored in landfills endlessly, nowadays most of the waste economies in the world are trying to recycle concrete rubble. The recycling is not such a problem, the technology has been long verified but the quality of the recycled concrete aggregate is unquestionably one of the primary assumption which leads to accomplish required properties of concrete. In fact, the recycling process is „crushing“ the concrete into particles with an effort to eliminate the cement paste on the surface of the aggregate. An ideal solution would be create a resistant and firm coating that would adhere perfectly to the cement matrix. This diploma thesis is focused on the properties of recycled concrete aggregate and methods of improvement and optimization of the concrete mix composition.
Mechanical activation of admixtures in concrete and verify the impact on physical and mechanical properties of fresh and hardened concrete
Prokopec, Zdeněk ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
This work is devoted to describe the possibilities of mechanical activations of admixtures used in concrete. Then, the verification options of grind fly ash, both from brown and black coal, from the classical as well as fluidized combustion and examination their impact on physical and mechanical properties of concrete, especially on long-term development to old age 180 days. Further attention is paid to assessing the impact of the use of mechanically activated fly ash on hydration heat evolution and the associated volume changes in the age of 1 to 90 days. In this work are presented the results of basic technological tests on concretes using admixtures, especially fly ash.
Testing ways of use of secondary raw materials replacing naturals aggregate.
Vašek, Tomáš ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
Master's thesis consists of two parts, theoretical and practical. In the theoretical section are listed basic information about alternative aggregates used for concrete mixture, like polystyrene, cinder and recycled concrete. Further, the influence of these alternative aggregates, used as secondary raw materials, on the behaviour and properties of fresh respectively hardened concrete. Possibilities of application concrete containing secondary raw materials are mentioned. In the practical part are experimentally verified physical and mechanical properties of concrete containing crushed waste polystyrene beads, furthermore thermal insulation properties and resistance to elevated temperatures is tested. Influence of heating plant cinder powder as active addition to concrete mixture was tested. As a next is prepared concrete with replacement of coarse aggregate by cinder and recycled concrete and tested. The influence of these secondary raw materials on workability, compressive strength, frost resistance and water permeability of concrete is also defined. The last part of research is focused on recycled concrete such as main material used in mixture of aggregates bonded with cement, dispose for base layers in roads. In conclusion are discussed results from experimental research and summary of knowledge’s about using polystyrene, cinder and recycled concrete as aggregates for concrete mixtures.
Effect of active ingredients, and their dosing to CHRL 28,90 days of age
Kodešová, Monika ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
Subject of this work is to design a batch of concrete with additives, which are to replace the cement of various doses so as to not adversely affect the properties of fresh and hardened concrete and simultaneously withstand the environment XF.
Optimization of the concrete composition with the use of recycled concrete aggregates
Skriňáková, Eva ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
Concrete as a building material is subject to continuous innovation and thanks to advanced technology and quantum of research, its properties are still improved. It is logical that the more concrete we produce, the more waste it arises. The volume of this waste can not be stored in landfills endlessly, nowadays most of the waste economies in the world are trying to recycle concrete rubble. The recycling is not such a problem, the technology has been long verified but the quality of the recycled concrete aggregate is unquestionably one of the primary assumption which leads to accomplish required properties of concrete. In fact, the recycling process is „crushing“ the concrete into particles with an effort to eliminate the cement paste on the surface of the aggregate. An ideal solution would be create a resistant and firm coating that would adhere perfectly to the cement matrix. This diploma thesis is focused on the properties of recycled concrete aggregate and methods of improvement and optimization of the concrete mix composition.
Testing ways of use of secondary raw materials replacing naturals aggregate.
Vašek, Tomáš ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
Master's thesis consists of two parts, theoretical and practical. In the theoretical section are listed basic information about alternative aggregates used for concrete mixture, like polystyrene, cinder and recycled concrete. Further, the influence of these alternative aggregates, used as secondary raw materials, on the behaviour and properties of fresh respectively hardened concrete. Possibilities of application concrete containing secondary raw materials are mentioned. In the practical part are experimentally verified physical and mechanical properties of concrete containing crushed waste polystyrene beads, furthermore thermal insulation properties and resistance to elevated temperatures is tested. Influence of heating plant cinder powder as active addition to concrete mixture was tested. As a next is prepared concrete with replacement of coarse aggregate by cinder and recycled concrete and tested. The influence of these secondary raw materials on workability, compressive strength, frost resistance and water permeability of concrete is also defined. The last part of research is focused on recycled concrete such as main material used in mixture of aggregates bonded with cement, dispose for base layers in roads. In conclusion are discussed results from experimental research and summary of knowledge’s about using polystyrene, cinder and recycled concrete as aggregates for concrete mixtures.
Mechanical activation of admixtures in concrete and verify the impact on physical and mechanical properties of fresh and hardened concrete
Prokopec, Zdeněk ; Holák, Michal (referee) ; Hela, Rudolf (advisor)
This work is devoted to describe the possibilities of mechanical activations of admixtures used in concrete. Then, the verification options of grind fly ash, both from brown and black coal, from the classical as well as fluidized combustion and examination their impact on physical and mechanical properties of concrete, especially on long-term development to old age 180 days. Further attention is paid to assessing the impact of the use of mechanically activated fly ash on hydration heat evolution and the associated volume changes in the age of 1 to 90 days. In this work are presented the results of basic technological tests on concretes using admixtures, especially fly ash.

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