Pozzolanic behaviour of a bagasse ash from the boiler of a Cuban sugar factory

Abstract

The paper presents a study of the pozzolanic reaction kinetics between calcium hydroxide and sugar cane bagasse ash (SCBAB) from the boiler of a sugar factory. A pozzolanic activity method (conductometric method) based on measurement of the electrical conductivity of the SCBAB/calcium hydroxide solution as the reaction proceeds is applied and the kinetic parameters are then quantified by applying a kinetic–diffusive model to the process. The kinetic parameters that characterise the process (in particular, the reaction rate constant and the free energy of activation) were determined with relative accuracy in the fitting process of the model. The pozzolanic activity is quantitatively evaluated according to the obtained values of the kinetic parameters. Other experimental techniques, such as X-ray diffraction and scanning electron microscopy, are also employed. Comparison with another bagasse ash calcined under controlled conditions in the laboratory is carried out. The results show the good pozzolanic properties of the SCBAB from the boiler of the sugar factory.