CHARACTERIZATION OF JEBAL MEIDOUB VOLCANIC ASH AND PUMICE AS CEMENT REPLACING MATERIALS FOR USE IN BLENDED CEMENTS

Abstract

The aim of this paper to evaluate the pozzolanic characteristics of the volcanic ash and pumice obtained from Jebal Meidoub (Meidoub Mountains) in western Sudan (Darfur) as potential Supplementary Cementitious Materials for use in blended cement and concrete. To achieve desired fineness, two types of local mills have been developed with high efficiency, one is a ball mill for laboratory purposes and another is a grinding mill for commercial production. Three natural Pozzolanic samples have been obtained, one is volcanic ash powder (MVA), another is pumice (MP), and the third contains a mixture of volcanic ash and pumice as found in the nature (MVP). This study has investigated the chemical and physical characteristics of the samples and their pozzolanic activities with Ordinary Portland cement (OPC) at different replacement levels of cement by weight, namely 10, 20, 30, 40, and 50%. The results of the chemical analysis have shown that all samples could be classified as Class N of the ASTM C618. The strength activity indices of the three samples at 20% level were found to be 81, 90, and 90% respectively. These results indicate that the Jebal Meidoub Pozzolans are potential supplementary cementitious materials for use in blended cement.