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Recyclation of dust from production of dry mortar blends
Ondrůšková, Nela ; Novotný, Radoslav (referee) ; Šoukal, František (advisor)
The work deals with the problem of disposal of ever-increasing waste (dust) from the production of building materials and examines the possibility of recycling dust dust into cement repair mortar. The aim of this work was to determine the composition of individual dust particles from the production of cement mixtures and to determine their mechanical properties, as well as to determine the ideal ratio of dust particles to each other when mixing the dust mixture and its mechanical properties. This mixture consisted mainly of dust from products based on Portland cement, aluminous cement, gypsum and lime hydrate. The mixture further replaced part of the cementitious mortar and the impact of the additive on the mechanical properties of the cementitious mortar was determined. X-ray fluorescence spectrometry was used to determine the elemental composition, and X-ray diffraction analysis was used to determine the mineralogical composition. Test specimens were prepared according to the ČSN EN 12390 standard. Mechanical strength tests were performed on the test specimens. A large part of the test specimens could not be subjected to mechanical tests because the test specimen did not solidify even after a long time. The individual measurements that could be made show that the mechanical properties of the dust samples show values which have shown that the dust cannot be recycled into the product due to its instability. Dust particles have too diverse composition and in combination with cementitious repair mortar do not have the required properties. The problem is especially the sampling from the data, which did not solidify at all and thus excluded the remaining samples with already good properties of the same sample. When designing the method of recycling, it was necessary to take into account which product of the company is most in demand, where recycling would also make economic sense, which is also an important indicator for the operation of the company today. Dust particles could prove successful in another product, but it would not be advantageous for the company now, so now the recycling of dust particles will not start and they will be further disposed of in the same way.
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The impact of metal powder recycling on the porosity of parts produced by Selective Laser Melting
Sůkal, Jan ; Hudák, Radovan (referee) ; Paloušek, David (advisor)
Diploma thesis deals with the influence of recycling of powder steel 1.2709 on porosity of parts processed by SLM technology. Theoretical part of this thesis gives an overview of the influence of selected process parameters of this additive technology on the porosity of manufactured parts. The presence of pores in the material is the main cause of worse mechanical properties compared to conventionally manufactured materials. Since the advantage of this technology is the possibility of wasteless production, one of the possible causes of pore formation and degradation of properties of the powder material is due to standard recycling by means of sieving to remove the contaminants generated during the construction. This paper compares the porosity of parts produced by two different machines, analyzes the possible consequences of sieving on powder properties, establishes recommendations for setting the recycling process, and compares the degree of influence of process parameters on porosity.
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Evaluation of industrial heritage
Navrátil, Oldřich ; Králová, Eva (referee) ; Zemánek, Václav (referee) ; Ryšková, Michaela (referee) ; Zemánková, Helena (advisor)
The main subject is evaluation of effective use in terms of care (not only within protection of monuments) in order to save and protect industrial heritage. Pointing out on critical issues connected with the end of production of traditional branches which played the key role in historical development of our cities. Nowadays abandoned buildings and sites are represented by memory of the place or its prosperity. New owners often don't share the positive approach to the industrial heritage, developers are seeking new sites, cities and inhabitants have developed new needs through the time. The work will demonstrate examples within European context and will make recommendations in monitoring and classification of industrial heritage to prevent undo able losses.
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Possibilities of utilizing waste from the production of cement-bonded particleboards in building materials
Bartoň, Andrej ; Vacula, Miroslav (referee) ; Bydžovský, Jiří (advisor)
This bachelor thesis deals with possible applications of waste created during cement-bonded particleboard in building materials production. The theoretical part of the thesis analyzes the individual components and processes in the production of cement-bonded particleboard, production processes during which the waste is produced, and the form and quantity the waste can be found in. The theoretical part focuses on the treatment of the various waste forms and their further use in modified or untreated form. In the practical part, the influence of the binder parts substitution on the cement matrix properties is verified. Fine loose waste from the cement-bonded particleboard was used for the sample production.
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Use of polymers in road constructions
Klusková, Jana ; Komenda, Radek (referee) ; Stehlík, Dušan (advisor)
The diploma thesis deals with the use of recycled polymers in asphalt mixtures. In the theoretical part of the thesis there is discussed the global issue of plastic waste including the experience of foreign countries, where this technology has already been introducted and used. The practical part is devoted to the proposal of using recycled plastic in asphalt mixture, description of used laboratory tests and the evaluating the effect of low-density polyethylen (LDPE) on the asphalt mixture type AC. There were performed tensile strenght tests, water resistant tests and stiffness modulus tests in the laboratory (E). The output of this work is an evaluation of measured values, processing of results and their interpretation depending on the possible use of this technology in Czech republic.
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Use of polymers in road constructions
Klusková, Jana ; Komenda, Radek (referee) ; Stehlík, Dušan (advisor)
The diploma thesis deals with the use of recycled polymers in asphalt mixtures. In the theoretical part of the thesis there is discussed the global issue of plastic waste including the experience of foreign countries, where this technology has already been introducted and used. The practical part is devoted to the proposal of using recycled plastic in asphalt mixture, description of used laboratory tests and the evaluating the effect of low-density polyethylen (LDPE) on the asphalt mixture type AC. There were performed tensile strenght tests, water resistant tests and stiffness modulus tests in the laboratory (E). The output of this work is an evaluation of measured values, processing of results and their interpretation depending on the possible use of this technology in Czech republic.
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Launching and Running a Company Using Project Management Methods
Šura, Jiří ; Szturc, Eugeniusz (referee) ; Smolíková, Lenka (advisor)
The thesis is focused on finding proper methods of business plan realisation, in order to launch an ecologic car wrecks disposal and recyclation company. Suggestions on how to conduct this project have been made according to IPMA competence baseline and analytic work has been done using MS Project tool. This thesis consists of theoretical information, analytical and practical part, focused on business plan description, and choice of a proper realisation methods.
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Low-energy recycling of poly(ethylen terephthalate) waste
Slabá, Jitka ; Beneš, Hynek (advisor) ; Cajthaml, Tomáš (referee)
This thesis deals with a new low-energy method of chemical recycling of poly(ethylene terephthalate) (PET) using natural oils as reagents and microwave irradiation to accelerate depolymerization. The results of experiments with PET waste and castor oil, when the reaction mixture was heated in microwave reactor, showed that a complete depolymerization of PET chain has occured. Optimal conditions for the depolymerization PET were established: wt. ratio of PET / castor oil = 1 / 9.7, when the molar ratio of ester bonds of PET / hydroxyl groups of castor oil = 1 / 2.7, catalyst : zinc acetate at wt 1% from the PET mass, reaction temperature ranging from 235 to 245řC and the reaction time 60 min. Decomposition experiments also showed, that microwave irradiation accelerated decomposition of PET. Depolymerization reactionin MW reactor was complete at 6x shorter reaction time than the decomposition in the classically heated reactor. The results of analysis showed that the resulting product,the recyclate, was composed of unreacted castor oil and polyol products, that contained partially or fully esterified structural unit of PET, which were ended by ester-linked units of castor oil.
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