Valorization of freshwater sediments through thermal treatment for alkali activation

• Main Authors: Fořt, Jan, Mildner, Martin, Scheinherrová, Lenka, Šál, Jiří, Keppert, Martin
• Format: Conference Proceeding
• Language: English
• Subjects: Availability; Chemical composition; Compressive strength; Construction industry; Construction materials; Dredging; Flexural strength; Heat treatment; High temperature; Lakes; Mechanical properties; Precursors; Raw materials; Road construction; Sediments; Thermogravimetry
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0146717

The construction industry is currently struggling with a shortage of primary raw materials that are needed for buildings, road construction in particular. Taking into account the availability issues, dredging operations in river bands, dams, and lakes associated with a big volume of excavated sediments represent a very interesting precursor source for the alkali-activated materials (AAMs) production. However, despite the good availability and favorable chemical composition, the alkali activation of WS was studied only rarely. This study investigates the potential of dredged freshwater sediments as alkali-activation precursors through elevated temperature exposure. The reactive amorphous phase content is increased by treatment at 800 °C and changes in the mineralogical composition are evaluated. The suitability of freshwater sediments as construction materials is accessed by the determination of the mechanical strength. The obtained results reveal, that the utilization of thermogravimetry can be viewed as an effective tool for the determination of optimal temperature treatment. Achieved values of compressive and flexural strength point to the potential of this material as the construction material, notwithstanding, follow-up research is required to increase the mechanical performance through mixtures optimization.