Synergistic effect and mechanism of waste glass on the mechanical properties and autoclave stability of cementitious materials containing steel slag

Abstract Incorporating solid waste into cement and concrete products can save natural resources and reduce environmental problems caused by the disposal of industrial solid waste. In this study, steel slag powder and waste glass powder were synergistically used to replace cement. The blended cementitious materials showed good mechanical strength and autoclave stability with the synergistic aid of steel slag and waste glass. This study used an autoclave experiment to accelerate the hydration reaction. Results suggested that waste glass as an amorphous siliceous material enriched hydration products and completely consumed f-CaO in steel slag under autoclave for 3 h. The expansion rate of the blended paste was the lowest, and the stability was the best when the mass ratio of ordinary Portland cement: steel slag powder: waste glass powder was 7:2:1. A complete reaction of f-CaO occurred in the steel slag in the presence of an excess of waste glass powder in the blended cementitious materials. An excessive waste of glass powder can cause alkali–silicon reaction with Na+ and K+ ions and lead to expansion.