TY - THES

T1 - Influence of the properties of different waste streams on gas-collecting base- and levelling layers with special focus on carbonate content in landfill technology

AU - Flechsenhar, Selina

N1 - embargoed until 18-04-2029

PY - 2024

Y1 - 2024

N2 - To achieve the European goal of a fully circular economy, it is necessary to develop new recycling options for mineral waste to preserve landfill capacities in the long term. One solution is to use landfill substitute construction materials (SCM), which can be made by recycling specific waste streams. These reduce the reliance on conventional building raw materials. The use of landfill SCM is an innovative and sustainable approach to landfill construction that helps to conserve natural resources in the long term. This master´s thesis deals with the use of different mineral waste streams, such as electric arc furnace slag, hollow glass, municipal solid waste incineration bottom ash, tar-containing asphalt, and track ballast, as SCM. It analyzes their impact on the properties of gas-collecting base- and levelling layers in landfill technology and focuses on the influence of the carbonate content. The evaluation of waste streams for use as landfill SCM considers both technical requirements and ecological aspects. The tests conducted adhere to the German legal frameworks and utilize a hierarchically structured decision tree to assess the suitability of future landfill SCM. The study identified methodological limitations in the prescribed regulations and formulated recommendations for future action. In the assessment of waste streams as SCM for landfill purposes, all samples show potential suitability, although some exceeded the carbonate limit value. All tested materials met the geotechnical requirements. A correlation between carbonate content and other tested parameters could not be established. The spatial differences in the carbonate content in the examined waste streams could be attributed to the regional geology and the availability of industrial raw materials in their original use. Finally, it was pointed out that there is a need for a comprehensive revision of the prescribed testing methods and their defined limiting values. This will enable waste streams to be recycled more efficiently while minimizing environmental impact. This work provides important insights into the assessment of the suitability of landfill SCM and demonstrates ways in which a circular construction industry can be further promoted.

AB - To achieve the European goal of a fully circular economy, it is necessary to develop new recycling options for mineral waste to preserve landfill capacities in the long term. One solution is to use landfill substitute construction materials (SCM), which can be made by recycling specific waste streams. These reduce the reliance on conventional building raw materials. The use of landfill SCM is an innovative and sustainable approach to landfill construction that helps to conserve natural resources in the long term. This master´s thesis deals with the use of different mineral waste streams, such as electric arc furnace slag, hollow glass, municipal solid waste incineration bottom ash, tar-containing asphalt, and track ballast, as SCM. It analyzes their impact on the properties of gas-collecting base- and levelling layers in landfill technology and focuses on the influence of the carbonate content. The evaluation of waste streams for use as landfill SCM considers both technical requirements and ecological aspects. The tests conducted adhere to the German legal frameworks and utilize a hierarchically structured decision tree to assess the suitability of future landfill SCM. The study identified methodological limitations in the prescribed regulations and formulated recommendations for future action. In the assessment of waste streams as SCM for landfill purposes, all samples show potential suitability, although some exceeded the carbonate limit value. All tested materials met the geotechnical requirements. A correlation between carbonate content and other tested parameters could not be established. The spatial differences in the carbonate content in the examined waste streams could be attributed to the regional geology and the availability of industrial raw materials in their original use. Finally, it was pointed out that there is a need for a comprehensive revision of the prescribed testing methods and their defined limiting values. This will enable waste streams to be recycled more efficiently while minimizing environmental impact. This work provides important insights into the assessment of the suitability of landfill SCM and demonstrates ways in which a circular construction industry can be further promoted.

KW - Landfill substitute construction materials

KW - carbonate content

KW - decision tree for suitability assessment

KW - sustainable landfill construction method

KW - Deponieersatzbaustoffe

KW - Karbonatgehalt

KW - Entscheidungsbaum zur Eignungsbewertung

KW - nachhaltige Deponiebauweise

M3 - Master's Thesis

ER -