Strength development and microstructure properties of slag activated with alkaline earth metal ions: a review study
Hadi Bahmani, Davood Mostofinejad
Abstract
This article reviews the microstructure properties and strength development of slag activated with calcium oxide, calcium hydroxide, magnesium oxide, barium hydroxide, carbide slag, and calcined dolomite. X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric/differential thermal analysis were used to evaluate the microstructure characteristics of activated slag. Furthermore, compressive strength test results were studied to evaluate the development of the strength of slag activated with alkaline earth metal ions. The results showed that slag samples activated with carbide slag and barium hydroxide, respectively, produced the lowest and highest compressive strengths. Moreover, among the activators of alkaline earth metal ions studied thus far, barium hydroxide produced the densest microstructure, lowest calcium-to-silicon ratio, and most hydration products. Slag activated with carbide slag produced the lowest calcium–silicate–hydrate (C–S–H) content compared with other activators of alkaline earth metal ions.