In this study, nano titanium dioxide and nano silica have been added in white Portland cement mortars. The dosage of nano- TiO2 was fixed to 3% while the dosage of nano-SiO2 was varied from 0%-3%. Water/binder ratio was 0.45% and binder/sand ratio was 1:3. The workability, water absorption, compressive and flexural strengths of mortars was measured. The permeability of mortars was measured using Nordest test and the carbonation resistance was measured in a carbonation chamber. The degradation of rhodamine B dye on the surface of mortars was measured after exposure of the white mortars to the ultraviolet light. Addition of nano-SiO2 increased the compressive and flexural strengths of mortars, reduced the water absorption of mortars and resisted the penetration of chloride ions. The self-cleaning of the white mortars was unaffected by the addition of nano-SiO2 particles.

Keywords: Nano silica, Nano titanium dioxide, White Portland cement mortars, Mechanical properties, Self-cleaning, Photocatalysis, durability, Chloride penetration, Carbonation.