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Development of chemically resistant sprayed mixture
Hermann, Radek ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
Production wastes for which a direct use in another production is found become secondary raw materials. There are several institutions in Czech Republic and in the world, which are currently dealing with the issue. This thesis deals with the issue of cementitious spray concrete mixtures and deals with the possibilities of using secondary raw materials and waste from production as partial replacement of binder and filler in these mixtures. The aim of this theses is to optimize the composition of additives in the recipe of the commercially produced pray mixture and to verify the influence of the degree of substitution of binder or filler by secondary raw materials on its physical-mechanical properties. The aim is to maintain or increase these properties while substituting the binder and filler as much as possible. After the evaluation of results, it is possible to say, by suitable optimization of the additives it is possible to achieve a significant improvement of the physical-mechanical properties of the mass and furthermore, from the results of this thesis follows, that by substitution of 100% fine filler in combination with substitution of 30% binder it is possible to maintain or increase the physical-mechanical properties after 28 days of curing and to significantly increase these properties after 90 days of curing. The results of this thesis are also related to the reduction of economic impact on production of the spray mixture, mainly due to the use of secondary raw materials.
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The possibilities regulation of production hydration heat of concrete with plasticizer
Hermann, Radek ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
This thesis studies the problematics of water reducing and high range water reducing admixtures and their influence on the process of hydration of cement pastes. The process of hydration is examined in this thesis both in terms of hydration heat and hydration temperature rise. Attention is also paid to the influence of plasticizers in combination with retarding admixture regarding rheological properties of modified fresh cement pastes and their mechanical properties after 3 and 7 days from mixing.
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Studium a vývoj polymer-cementových kompozitů s důrazem na vysoký obsah druhotných surovin a kompenzaci objemových změn
Hermann, Radek ; Bydžovský, Jiří (referee) ; Reitermann, Pavel (referee) ; Kolísko, Jiří (referee) ; Drochytka, Rostislav (advisor)
Reducing of humanity's carbon footprint is currently one of the main directions of global research. Another significant problem is the disposal, recycling and secondary use of waste materials produced from a wide range of industries and municipal waste. This thesis deals with the problematics of polymer-cement composites, which are most often used for rehabilitation, reprofiling and structural repairs, especially of concrete structures. The thesis examines and verifies the possibilities of utilization of a large amount of secondary raw materials and waste as a substitute for cement as a primary binder. At the same time, the work deals with the full replacement of the primary filler with waste raw materials, for which there is currently no other use. The work also addresses and verifies the influence of several commonly available commercial polymer dispersions. The work deals with the use of liquid, but also powdered polymeric additives of various bases. The work also deals with the problematics of volume changes of the hydration process of polymer-cement composites and the effect of volume changes on the physical-mechanical properties of composites. The influence of volume changes that occur during the hydration of polymer-cement composites is a significant criterion in the selection and use of these composites. The volume changes of the material have a great influence especially on the maximum layer thickness and the maximum area that can be repaired with the material without the risk of cracks and the need to create a working joint. The results of this work are associated with a reduction in the economic and environmental impacts of production and use of polymer-cement building materials and increase the usability of these materials mainly due to the possibility of remediation of larger areas than previously possible.
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Possibilities of Using Waste Materials in Trenchless Renovation Piping Systems
Majerová, Jana ; Drochytka, Rostislav ; Hermann, Radek ; Figala, Petr
Properties of the resin system are key properties in the CIPP trenchless pipeline repair system. Fillers affect the properties of the resin system and the cost of renovation. One of the ecologically and economically attractive options is the use of secondary raw materials. The article describes the properties of some suitable secondary raw materials and their influence on the properties of the resin system in comparison with traditional fillers The article compares three types of secondary waste materials and the reference filler. The SiO2 content, the particle size of the filler and the mechanical parameters of the proposed recipes are most important.
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Assessment of Physical-Mechanical Properties of Polymer Adhesive Materials
Hermann, Radek ; Majerová, Jana ; Figala, Petr
This paper deals with the problematics of polymer adhesive mortars. In this study, the vinyl ester and epoxy resins filled with siliceous filler were used. This paper studies physical-mechanical properties of developed mortars. The compressive strength, flexural strength, and abrasion resistance. The maximum filling ratio for each mortar was found while preserving the applicability in masonry way (by spatula). The results show that the amine-based epoxy mortar exhibits lower physical-mechanical properties than the vinylester-based adhesive mortar, except for the abrasion resistance, in which the epoxy-based composite has achieved significantly better results.
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Development of chemically resistant sprayed mixture
Hermann, Radek ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
Production wastes for which a direct use in another production is found become secondary raw materials. There are several institutions in Czech Republic and in the world, which are currently dealing with the issue. This thesis deals with the issue of cementitious spray concrete mixtures and deals with the possibilities of using secondary raw materials and waste from production as partial replacement of binder and filler in these mixtures. The aim of this theses is to optimize the composition of additives in the recipe of the commercially produced pray mixture and to verify the influence of the degree of substitution of binder or filler by secondary raw materials on its physical-mechanical properties. The aim is to maintain or increase these properties while substituting the binder and filler as much as possible. After the evaluation of results, it is possible to say, by suitable optimization of the additives it is possible to achieve a significant improvement of the physical-mechanical properties of the mass and furthermore, from the results of this thesis follows, that by substitution of 100% fine filler in combination with substitution of 30% binder it is possible to maintain or increase the physical-mechanical properties after 28 days of curing and to significantly increase these properties after 90 days of curing. The results of this thesis are also related to the reduction of economic impact on production of the spray mixture, mainly due to the use of secondary raw materials.
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The possibilities regulation of production hydration heat of concrete with plasticizer
Hermann, Radek ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
This thesis studies the problematics of water reducing and high range water reducing admixtures and their influence on the process of hydration of cement pastes. The process of hydration is examined in this thesis both in terms of hydration heat and hydration temperature rise. Attention is also paid to the influence of plasticizers in combination with retarding admixture regarding rheological properties of modified fresh cement pastes and their mechanical properties after 3 and 7 days from mixing.
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