The present methods used for quantification of the blending components like fly ash and slag in PPC and PSC are indirect methods, there is no specific chemical method defined by the standards to directly quantify these blending components. The methods currently adopted are based on determination of insoluble residue for fly ash content in PPC and an optical microscopy based quantification or density separation method for slag in PSC, or in general the Lime balance method is also used for theses blended Cements, which are observed to give a fair indication of the fly ash/ slag contents in these blended cements. Especially Composite cements with fly ash and slag, would necessitate a reliable quantification method for these two components when present together in these Cements.
Initial work has been carried out on assessing the different chemical selective dissolution methods for quantification of fly ash and slags in composite Cements. The paper reviews the different selective dissolution methods reported for quantification of these blending components. The Paper further compares the analysis results of optimized method at the authors laboratory with the results obtained using the method adopted by EN standards for quantification of fly ash and slag in composite cements.
The reproducibility of the method has been observed to be satisfactory, as the standard deviation of the measurement was within 0.5-1%. Some attempts have also been made to validate the method through use of alternative quantification techniques wherever possible for these blending components. . The paper was presented and published at 10th NCB Int Seminar