Study on the fluidity of foamed alkali-activated slag cementitious material (AASCM)

Abstract

This study aims to investigate the evolution patterns of fluidity and rheological properties of AASCM under varying dosages of foaming agent and particle sizes of filling aggregate. The flow characteristics of AASCM are significantly affected by the filling aggregate's size and the foaming agent's dosage. Specifically, an increase in filling aggregate size (D(4,3) ϵ [26 μm, 69 μm]) enhances the fluidity of foamed AASCM, while an increase in foaming agent dosage reduces fluidity. These observed variations can be attributed to the presence of particle voids, the specific surface area of the aggregate, as well as the quantity and spatial distribution of bubbles within the slurry. A bubble-particle packing model is established, and by calibrating the simulation error coefficient to 1.1, the study investigates the evolution of water film thickness (WFT) in foamed AASCM with slurry expansion degree. It is observed that bubbles in the slurry affect the fluidity by altering the overall compactness and specific surface area of the foamed slurry, subsequently modifying the WFT.

Keywords

• Foamed backfill
• Fluidity
• Foaming agent dosage
• Particle size of filling aggregate
• Water film thickness