Frost scaling of blast-furnace slag mortar with sodium monofluorophosphate
ABSTRACT: In this research, the application of sodium monofluorophosphate (Na-MFP) as a curing solution and surface treatment compound to improve the frost salt scaling resistance of carbonated blast furnace slag mortar was evaluated. The 30% by weight Na-MFP solution in water was used as a curing solution or surface treatment compound, and the specimens were exposed to accelerated carbonation controlling 3% CO2 concentration with 65% relative humidity. The optimum mix designs can be achieved by using air-entraining agent dosage of 0.07% by weight of cementitious material (Cugla MMS con 17% LBV), incorporating to the Na-MFP application. The experimental results show that the optimized mixtures have acceptable frost scaling durability which is equivalent to the performance of ordinary Portland cement mixture. The pore coarsening of carbonated matrix was obviously reduced, and the quality of the transition zone between sand and matrix has been significantly improved. The water absorptions of treated specimens were decreased subsequently.