Assessment of Ionic Composition of Fresh Cement Blends System with Addition of SCMs and Conductive Materials

Abstract

In this experimental study, an attempt has been made to investigate the effect on the ionic composition of cement system at early age upon the addition of supplementary cementitious materials (SCMs) and conductive additives. The ionic composition of cement system refers to the type and concentration of ionic species and it varies depending on the type of cement and degree of hydration. Cement system containing fly ash, silica fume, and ground granulated blast furnace slag (GGBS) in different proportions were blended to examine the effect of SCMs on the ionic concentration. Apart from SCMs, conductive additives like graphite powder and inorganic salt were also included in the study. The pore solution, formed as a result of the hydration of cement, contains a complex mixture of ions. The ionic conductivity of the pore solution is determined from the concentration of various ionic species. Ionic conductivity is responsible for the electrical, chemical, and mechanical performance of the cement system, and hence, understanding the same is essential. Pore solution is extracted in the early age of the hydrating cement system by centrifugation, and with ion chromatographic technique, the concentrations of ions in the pore solution are determined and the results and discussion are compiled in this paper. From the study, silica fume and magnesium-based salt were observed to be an effective additive in improving the conductivity of the pore solution. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.