Comparative Analysis of the Influence of Sodium and Potassium Silicate Solutions on the Kinetics and Products of Slag Activation

摘要: This paper primarily explores the influence of alkali cation (Na or K) on reaction kinetics, product formation, gel structure, and mechanical properties activated slag systems. For same activator Ms, i.e., molar SiO2–M2O ratio (M = Na K), a shorter induction period, larger acceleration peak, consequently, higher amount total heat release under isothermal conditions is observed for K-silicate pastes. The early-age compressive strengths in these systems roughly relate to response. later-age (7 days beyond) are be Na-silicate systems, which corroborated by: (1) amounts C–(A)–S–H this system indicated by thermal analysis-based approximate quantification method, (2) combined intensities Q1 Q2 structures that point increased degrees reaction, lower unreacted obtained from 29Si magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. NMR spectra also show evidences Al-substituted C–S–H gel, with substitution when Na-silicates used.