Estimating reactivity of pozzolanic materials by a spectrophotometric method

Following earlier work on estimating the reactivity of pozzolanic materials, three classes of pozzolanas have been further investigated, to ascertain whether or not a more linear calibration curve is possible. A better linear correlation exists when separate calibration curves between absorbance and lime-pozzolana mortar strength values for different classes of pozzolanas are drawn. Pozzolanic activity has been characterized by a parameter called pozzolana reactivity index. Practical aspects and validity of the method are discussed. A good correlation coefficient between absorbance and pozzolana reactivity index values in agreement with lime-pozzolana mortar strength was obtained.