Characterization of sugar cane bagasse ash from Burkina Faso for cleaner cement production: Influence of calcination temperature and duration

In this study, the sugar cane bagasse from Burkina Faso has been calcined at temperatures ranging from 550 to 750 °C with a heating stage of 2 or 3 h to produce pozzolanic ashes as supplementary cementitious materials for eco-cement production. The ashes obtained were subsequently characterized for their chemistry, mineralogy, and pozzolanic activity. The results of the characterization have shown that the ashes are rich in amorphous silica with a high Blaine specific area and a density around 2,5 g/cm3. The ashes are siliceous pozzolan type F. The main crystalline phases identified in these ashes are quartz (SiO2), calcite (CaCO3), muscovite (KAl2AlSi3O10(OH)2), microcline (KAlSi3O8), and hematite (Fe2O3). Frattini's test has shown that all ashes own a pozzolanic activity due to the formation of CSH resulting from the reaction between the portlandite of cement and amorphous silica of ashes. The strength activity index evaluated with 25 wt% cement replacement by SCBA is greater than the minimum value of 75% required by the standard for all the ashes except those prepared at 700 °C for 3 h, 750 °C for 2 or 3 h. Thus, these ashes can be used as a partial substitute for clinker in cement production.