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Advanced material based on secondary raw materials for construction of subgrade layer
Hrubý, Jakub ; Luňáček,, Martin (referee) ; Černý, Vít (advisor)
The diploma thesis deals with the development of a new material for the establishment of a layer of the ground body of a railway undercarriage purely on the basis of secondary raw materials. The theoretical part presents the characteristics of structural layers, materials used for bonded substrates, including their requirements. The following are the general conditions for the creation of base layers from purely secondary raw materials and previous experience with the issue. The introduction of the experimental part of the thesis sets out the basic parameters of secondary raw materials (construction recyclates, waste from railway bed cleaning, dust from cement plant) and energy by-products (fly ash, coal slag and municipal waste incinerator), which together form the raw material base. Grain size, absorbency, moisture, bulk density, chemical analysis and pollutant content were determined on the raw materials. Bulk densities and compressive strengths of the bonded mixtures were determined. The optimum humidity of all mixtures was determined by the Proctor standard test. Experimental verification was performed on testing of bonded mixtures in order to verify the effect of cement dose, when the original dose of 8% was optimized for construction recycled and slag from municipal waste incinerator to 4%, due to high strengths ranging from 4.5 to 6.0 MPa. Further optimization also included the addition of an energy by-product in a proportion of 10% of the weight of the secondary raw material. At the end of the experimental part, two optimal recipes were selected (recycled concrete with 4% cement and 10% fluid fly ash; slag from a municipal waste incinerator with 3% cement and 10% fluid fly ash), which underwent advanced testing in the form of frost resistance and resistance to water and a functional sample was designed. The final functional sample is recycled concrete with cement and 10% addition of fluid fly ash, which is suitable for core layers without frost loading.
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The use of asphalt recycled materials in the base and subbase layers of pavements
Tanečková, Pavlína ; Hýzl, Petr (referee) ; Stehlík, Dušan (advisor)
This thesis consists of theoretical and practical parts. The theoretical part gathers available information on the current state of construction and demolition waste management. This part discusses foreign experiences with SDW management, provides basic information on the introduction of circular economy. Equally important is the environmental impact, which is discussed from the perspective of Decree No 283/2023 Coll. It also provides basic information on construction and demolition waste and describes the recycling process. It also discusses the most common types of recyclates and their use in roads. The practical part of this thesis verifies the possibilities of using asphalt recyclates and their mixtures cemented with asphalt emulsion or hydraulic binder. The main objective was to verify the possibilities of using these recyclates in cemented subbase layers for urban roads. These possibilities were verified and then compared by means of laboratory tests. Finally, a comparison of cemented mixtures of asphalt recyclates with specific binder dosage and low temperature heating of the mixture for optimum compaction to the desired strength values using recyclates is made.
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Advanced material based on secondary raw materials for construction of subgrade layer
Hrubý, Jakub ; Luňáček,, Martin (referee) ; Černý, Vít (advisor)
The diploma thesis deals with the development of a new material for the establishment of a layer of the ground body of a railway undercarriage purely on the basis of secondary raw materials. The theoretical part presents the characteristics of structural layers, materials used for bonded substrates, including their requirements. The following are the general conditions for the creation of base layers from purely secondary raw materials and previous experience with the issue. The introduction of the experimental part of the thesis sets out the basic parameters of secondary raw materials (construction recyclates, waste from railway bed cleaning, dust from cement plant) and energy by-products (fly ash, coal slag and municipal waste incinerator), which together form the raw material base. Grain size, absorbency, moisture, bulk density, chemical analysis and pollutant content were determined on the raw materials. Bulk densities and compressive strengths of the bonded mixtures were determined. The optimum humidity of all mixtures was determined by the Proctor standard test. Experimental verification was performed on testing of bonded mixtures in order to verify the effect of cement dose, when the original dose of 8% was optimized for construction recycled and slag from municipal waste incinerator to 4%, due to high strengths ranging from 4.5 to 6.0 MPa. Further optimization also included the addition of an energy by-product in a proportion of 10% of the weight of the secondary raw material. At the end of the experimental part, two optimal recipes were selected (recycled concrete with 4% cement and 10% fluid fly ash; slag from a municipal waste incinerator with 3% cement and 10% fluid fly ash), which underwent advanced testing in the form of frost resistance and resistance to water and a functional sample was designed. The final functional sample is recycled concrete with cement and 10% addition of fluid fly ash, which is suitable for core layers without frost loading.
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