Thermally Treated Waste Silt as Filler in Geopolymer Cement

This study aims to investigate the feasibility of including silt, a by-product limestone aggregate production, as filler in geopolymer cement. Two separate phases were planned: The first phase aimed determine optimum calcination conditions waste silt obtained from Società Azionaria Prodotti Asfaltico Bituminosi Affini (S.A.P.A.B.A. s.r.l.). A Design Experiment (DOE) was produced, and raw calcined accordingly. Geopolymer cement mixtures made with sodium or potassium alkali solutions tested for compressive strength leaching. Higher temperatures showed better strength, regardless liquid type. By considering leaching, X-ray diffraction (XRD) analysis, temperature time selected 750 °C 2 h. second focused on determining amount (%) that could be used mixture. results suggested addition about 55% (total solid weight) can improve geopolymers Na K activators. Based leaching test, cumulative concentrations released trace elements specimens into leachant lower than thresholds European standards.