Expansion behavior and microstructure change of alkali-activated slag grouting material in sulfate environment

Abstract

In this paper, according to the alkalinity of 4 wt%, 5 wt%, and 6 wt%, alkali-activated slag grouting material (AASGM) specimens were prepared by mixing waterglass (sodium silicate) with a modulus of 2.0 and slag. The specimens were immersed in pure water and sodium sulfate solutions with a concentration of 1–4 wt% for 90 days. The linear expansion, mass change, mechanical properties, and microstructure of the specimens were measured and analyzed. The results indicate that the main gel products were C-A-S-H gel in this process. The AASGM samples presented slight expansion, a small increase in mass, essentially unchanged compressive strength, and good anti-sulfate corrosion performance.