Calcium sulfoaluminate (CSA) cements, due to low synthesis temperature and limestone requirement, reduced thermal input and CO2 generation, may contribute to a sustainable development which can be further enhanced using industrial wastes and byproducts in the manufacturing process. Clinkers with high conversion degrees towards 4CaOּ3Al2O3ּSO3 were obtained heating for two hours in a laboratory electric oven, at temperatures ranging from 1100° to 1350°C, raw mixes consisting of limestone (up to 40%), red mud (up to 16%), bauxite (up to 25%), fluidized bed combustion waste (up to 35%) and pulverized coal ash (up to 41%). Every CSA cement (clinker plus about 20% desulfogypsum) was paste hydrated and characterized by XRD, DTA-TGA and SEM. Moreover mercury porosimetry showed that pastes cured even at early ages have a bimodal pore size distribution with the region of smaller pores (threshold pore radius, 20-25 nanometers) largely prevailing on the other (threshold pore radius, 150-200 nanometers).
Synthesis, hydration properties and environmentally friendly features of calcium sulfoaluminate cements / G. L., Valenti; M., Marroccoli; Montagnaro, Fabio; M., Nobili; A., Telesca. - STAMPA. - (2007), pp. W3 11.2-1-W3 11.2-12. (Intervento presentato al convegno 12th International Congress on the Chemistry of Cement tenutosi a Montreal, Canada nel 8-13 Luglio).
Synthesis, hydration properties and environmentally friendly features of calcium sulfoaluminate cements
MONTAGNARO, FABIO;
2007
Abstract
Calcium sulfoaluminate (CSA) cements, due to low synthesis temperature and limestone requirement, reduced thermal input and CO2 generation, may contribute to a sustainable development which can be further enhanced using industrial wastes and byproducts in the manufacturing process. Clinkers with high conversion degrees towards 4CaOּ3Al2O3ּSO3 were obtained heating for two hours in a laboratory electric oven, at temperatures ranging from 1100° to 1350°C, raw mixes consisting of limestone (up to 40%), red mud (up to 16%), bauxite (up to 25%), fluidized bed combustion waste (up to 35%) and pulverized coal ash (up to 41%). Every CSA cement (clinker plus about 20% desulfogypsum) was paste hydrated and characterized by XRD, DTA-TGA and SEM. Moreover mercury porosimetry showed that pastes cured even at early ages have a bimodal pore size distribution with the region of smaller pores (threshold pore radius, 20-25 nanometers) largely prevailing on the other (threshold pore radius, 150-200 nanometers).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
