Investigation into Pozzolanic Activity Component of Basalt and Pumice

Abstract

To evaluate the feasibility of using basalt and pumice as pozzolanic materials in a cement-based material, this paper is focused on the pozzolanic activity component (PAC) of basalt and pumice. PAC was explored as a characteristic index of potential pozzolanicity to express the intrinsic capacity of pozzolans regardless of particle size and other external factors. PAC was calculated as the product of chemical composition (SiO2+Al2O3+Fe2O3) content and amorphous phase content in rock; the former was analyzed using a wet chemical analysis, and the latter was determined by X-ray diffraction (XRD). Using chemical composition data, petrographic characteristics, powder XRD, and pozzolanic activity index data, it was summarized that both basalt and pumice had significant pozzolanicity and were suitable for use as supplementary cementitious materials. The relationship between the PAC and the pozzolanic activity index was evaluated through the ratio of mortar strengths achieved therewith. The results could be used to select basalt and pumice for use as pozzolans.