Utilization of Fly Ash from Lignite Combustion in Materials Sealing Hydro-Technical Structures

Abstract

In Poland, approximately 2 million hectares of agricultural land are at risk of flooding, which constitutes approximately 7% of the country’s area, half of which is protected by flood embankments. The total length of the embankments is approximately 8.5 thousand km. kilometers. The age of the embankments and their related technical condition, as well as insufficient funds allocated for maintenance and renovation, mean that the flood risk in the areas protected by the embankments is higher than would result from the geometric parameters of the embankments and floods assumed for their design. The need to renovate embankments, including their sealing, causes an increase in interest in new technological and material solutions, and it is expected that these solutions will be pro-ecological: low-emission and consistent with the idea of a circular economy. The research was aimed at presenting the possibility of using fly ash from lignite combustion (low-rank coal) in Pątnów Power Plant, in raw form and fractions separated from it. The article presents the method of preparation and properties of hardening slurries containing mineral by-products of coal combustion. The tests showed the usefulness of the fly ashes used as the main component of hardening slurries. Additionally, a beneficial effect of the fine fraction (0–30 μm) of fly ash on the properties of the slurry, especially on tightness and hydraulic conductivity, was found.