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Electrically conductive composites based on secondary raw materials
Baránek, Šimon ; Šteffan,, Pavel (referee) ; Černý, Vít (advisor)
Electroconductive composites are modern materials that are commonly used in many industries such as the construction industry among others. For example these materials can be useful as sensors for monitoring changes in constructions. The aim of this thesis is the research of electrically conductive silicate composite based on secondary raw materials. The design of this composite is based on the development of its own mixtures and experimental verification of the effect of the structure. The introduction part consists of a detailed analysis of 15 materials. Samples of the 5 fine and 2 coarse electrically conductive fillers were tested. Composite with filler Condufit C4 was selected as representative for type of fine fillers. Composite with filler Supragraphite C300 was selected as representative for type of coarse fillers. The selection of the composites was based on the impedance of the fabricated composites with these fillers. Subsequently, the individual components of the primary mixture were substituted. The cement was replaced by high-temperature fly ash in the amount of 20, 30, and 40 %, the aggregate of a similar fraction was replaced by steel sawdust, and the primary electrically conductive fillers were replaced by secondary ones in the amount of 30 and 50 %. All proposed replacements reduced the impedance of the composite. The most effective replacement for impedance reduction was replacement with waste graphite (up to 92 % reduction), which also slightly improved the mechanical properties of the composite. The result of this thesis is an optimized electrically conductive composite based on secondary raw materials with a fine type of filler with 30 % replacement by waste graphite "odpad vysavač"which achieves an impedance of 5 ohms. The partial goal of this thesis is a verification of the influence of moisture on the impedance of composites. Results are significantly affected by moisture when using the coarse type of filler, when using the fine type are not.
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Silicate Conductive Composites with Graphite Fillers
Baránek, Šimon ; Drochytka, Rostislav
Electroconductive composites are modern materials that are commonly used in many industries such as construction industry and machine-building industry. For example, these materials can be useful as sensors for monitoring changes in constructions, shielding stray currents from electrification networks, shielding electromagnetic radiation in operating rooms, cathodic protection against moisture or overvoltage protection of buildings. The topic of this post is the research of electrically conductive silicate composites with graphite-based fillers. In this research, composites with different ratios and types of graphite were tested and electroconductive properties such as impedance were monitored, as well as physical-mechanical properties such as strength. It was found that by adding 10 wt. graphite into the mixture reduces the impedance of the composites by 50 % and the compressive strength is reduced by approximately 40 %.
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Electrically conductive composites based on secondary raw materials
Baránek, Šimon ; Šteffan,, Pavel (referee) ; Černý, Vít (advisor)
Electroconductive composites are modern materials that are commonly used in many industries such as the construction industry among others. For example these materials can be useful as sensors for monitoring changes in constructions. The aim of this thesis is the research of electrically conductive silicate composite based on secondary raw materials. The design of this composite is based on the development of its own mixtures and experimental verification of the effect of the structure. The introduction part consists of a detailed analysis of 15 materials. Samples of the 5 fine and 2 coarse electrically conductive fillers were tested. Composite with filler Condufit C4 was selected as representative for type of fine fillers. Composite with filler Supragraphite C300 was selected as representative for type of coarse fillers. The selection of the composites was based on the impedance of the fabricated composites with these fillers. Subsequently, the individual components of the primary mixture were substituted. The cement was replaced by high-temperature fly ash in the amount of 20, 30, and 40 %, the aggregate of a similar fraction was replaced by steel sawdust, and the primary electrically conductive fillers were replaced by secondary ones in the amount of 30 and 50 %. All proposed replacements reduced the impedance of the composite. The most effective replacement for impedance reduction was replacement with waste graphite (up to 92 % reduction), which also slightly improved the mechanical properties of the composite. The result of this thesis is an optimized electrically conductive composite based on secondary raw materials with a fine type of filler with 30 % replacement by waste graphite "odpad vysavač"which achieves an impedance of 5 ohms. The partial goal of this thesis is a verification of the influence of moisture on the impedance of composites. Results are significantly affected by moisture when using the coarse type of filler, when using the fine type are not.
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