Comparison of the application of titanium dioxide and nanosilica and silicafume in the self-cleaning property of concrete for sustainable development

Photocatalytic self-cleaning is one of the most important uses of nanotechnology in the building industry. In this paper, we investigate the effect of using silicafume and titanium dioxide and nano-silica on increasing or decreasing the self-compressive properties of precast concrete components in architectural view of concrete structures. Type I-42.5 cement was used according to American Society for Testing and Materials (ASTM) -C150 specifications. Silicafume conforming to ASTM-C1240 standard specifications in the concrete blend was used as a replacement for cement. For investigation the use of TiO2 on the reduction of environmental contamination paint on the surfaces of precast concrete, three designs with zero and 2.5% and 5% TiO2 percentages were used instead of cement in the mix design. Better results were obtained with the sample with 2.5% and 5% TiO2 compared to the sample without titanium dioxide addition. The results show that TiO2 with 5% cement replacement with silicon with 20% cement replacement than 3% Nano-silica has more potential to improve the environmental properties of concrete facades of buildings in heavily contaminated cities in terms of concrete surface cleanliness and cleanliness. Better results were obtained with the sample with 2.5% and 5% TiO2 compared to the sample without titanium dioxide addition. The results show that TiO2 along with silicafume and Nano-silica has great potential to improve the environmental properties of the concrete facade of buildings in cities exposed to high contamination in terms of surface cleaning and cleaning.