Durability of blast-furnace slag mortars subjected to sodium monofluorophosphate application

The aim of this study is to investigate the effect of sodium monofluorophosphate (Na-MFP) on frost scaling durability and transport properties of carbonated blast-furnace slag cement (BFSC) mortar. The application of Na-MFP solution as curing solution and also surface treatment compound for BFSC mortar was evaluated. Three different Na-MFP solutions with concentrations of 10%, 20% and 30% by weight. in water were used as curing solution and surface treatment compound. The experimental results reveal that both techniques significantly improve the frost salt scaling durability and microstructure of carbonated blast-furnace slag mortar. Moreover, the carbonation rate and capillary water uptake of the treated mortars were substantially decreased compared with the untreated specimen. The mortars cured in Na-MFP solution show higher compressive strength than the untreated control after carbonation exposure. In general, the durability performances were improved when increasing the concentration of the Na-MFP solution applied.