Study on the pozzolanic properties of a natural Cuban zeolitic rock by conductometric method: Kinetic parameters

Natural zeolite is a type of mineralogical material containing large quantities of reactive SiO2 and Al2O3. These materials have been used in the cement industry as a supplementary cementing material. Like other pozzolanic materials the zeolite contributes to improve the mortar and concrete performances mainly through the pozzolanic reaction with calcium hydroxide (CH). The pozzolanic reactivity of this type of material in comparison with other pozzolans is of great interest.The current paper presents a study about the pozzolanic activity of a natural Cuban zeolitic rock. The pozzolanic activity in a zeolitic material/CH solution is investigated by means of electrical conductivity measurements and latter on the kinetic parameters are quantified by applying a kinetic–diffusive model to process. The kinetic parameters that characterize the process (in particular the reaction rate constant) were determined in the fitting process of the model. The index of pozzolanic activity evaluated according to the obtained values of the reaction rate constant permits to characterize the pozzolanic activity of these materials in a rigorous way.The results show that this Cuban zeolitic rock is a natural material with high pozzolanic activity. Also, these results allow corroborating the direct influence of the fineness of zeolitic material on the pozzolanic and mechanical properties.