New Eco-Friendly Calcium Sulfoaluminate Clinkerization Method Using Construction and Demolition Waste, and Product Life Cycle Assessment

This paper reports the use of siliceous and calcareous construction and demolition waste (CDW) and laminated glass in the manufacture of eco-friendly calcium sulfoaluminate-based cement clinkers. The Bogue method is applied to waste mixtures to establish their initial oxide content before performing clinkerization at 1250 °C. The Rietveld method is used to quantitatively determine the phases formed in 12 of the clinkersas well as the microstructure characterization using the FTIR, and SEM techniques. Ye'elimite, larnite, anhydrite, brediggite, and gehlenite are the clinkerization products formed. Variation in the concentrations of CDW-derived aluminum and magnesium favor the formation of ye'elimite and brediggite, respectively, at the expense of the existing larnite. The formation of gehlenite occurs at the above-mentioned temperature due to the thermodynamic instability of the ye'elimite. The resulting carbon footprint of eco-friendly CSA cement containing up to 20% CDW is 8.1% smaller than that of commercial CSA cement.