Fabrication of carbon sequestered superhydrophobic cementitious composites for efficient environmental stability, chloride ion resistance, and freeze-thaw resistance

In this study, a simple and novel preparation of carbon sequestered superhydrophobic cementitious composites was developed by leveraging the prepared carbonated fly ash (CFA) with constructed rough structures by the co-mineralization reaction of carbide slag and fly ash, combined with trace amounts of low-surface-energy fluoroalkylsilane. The effect of CFA preparation process (carbide slag content and termination pH) on the wettability, compressive strength, environmental stability, chloride ion resistance, freeze-thaw resistance, and microscopic structure of cementitious composites was investigated. The increase in termination pH and carbide slag content for the preparation of CFA made the prepared cementitious composites possess excellent superhydrophobicity, compressive strength, environmental stability, and surface durability. Furthermore, the superhydrophobicity imparted to the cementitious composite excellent chloride ion resistance and freeze-thaw resistance. This approach broadens the application prospects of superhydrophobic cementitious composites and provides a new strategy for extending the extension of the service life of buildings in extreme environments.