Moisture transport properties of alkali-activated binders

Abstract Despite the potential environmental benefits of alkali-activated materials (AAMs), there is still a need for deeper understanding of their durability under the combined action of carbonation and chloride ingress, which can lead to the corrosion of the reinforcing steel embedded in alkali-activated concrete. The moisture state in the porous cementitious material is an essential durability factor that should be accurately predicted to model the simultaneous ingress of chloride ions and carbon dioxide in unsaturated conditions, such as those found in marine splash zones. In this research, the moisture permeability properties of aged AAMs were investigated, and two moisture transport models, namely, the single and dual permeability models, were implemented to assess the moisture state in AAMs. The findings indicate that the dual permeability model more accurately predicts the moisture state in AAMs by considering the presences of both small and large pore regions that coexist in blended cementitious systems.