Microstructure and phase evolution of alkali-activated steel slag during early age

This work aims to investigate the early age evolution of alkali-activated steel slag under curing condition of 60 degrees C. Microstructural characterization and reaction degree of alkali-activated steel slag (Isothermal calorimetric, scanning electron microscope, Transmission electron microscopy, Fourier Transform Infrared Spectrometer, and Si-29 nuclear magnetic resonance) were carried out. The results showed that the densifying microstructure of aluminosilicate gel significantly increases, attributing to the increasing of reaction degree due to the formation of Si-O-T, in the early evolution of alkali-activated steel slag at 60 degrees C curing condition. The Si-29 structure of Q(0) in steel slag gradually converted into Q(1) and Q(2) in the intermediate products which represented the formation of aluminosilicate gels. The evidence indicated that the steel slag can be an alternative raw material in alkali activated application. (C) 2019 Elsevier Ltd. All rights reserved.