TiO2 is a primary photocatalytic ingredient. If incorporated into building materials, it can keep surfaces clean and significantly reduce smog-forming air pollutants. Many researchers have focused on the ability of Nano TiO2 to reduce NOx emissions or other pollutants. However, developing countries are unable to widely utilize Nano materials due to cost and technology barriers, in spite of their great need to find means for protecting structures from pollution and improve air quality. Some studies proved that micro TiO2 (commercial grade) also has photocatalytic properties. However, the effect of this inclusion on key mechanical and durability properties needs to be verified before being recommended for wide use. In this research the effect of commercial grade TiO2 powder on fresh state flow, compressive strength, shrinkage, sulfate resistance and carbonation. The results indicated that TiO2 decreased the workability as mortars became more sticky and dry with increased TiO2 content. The compressive strength was also reduced in TiO2 containing samples compared to the control samples especially at early ages. However, TiO2 powder as an additive in mortar was useful in reducing carbonation due to the filler effect. No samples in the current investigation showed signs of cracking or expansive mass loss due to sulfate exposure. It is recommended that TiO2 powder should be used as an additive to the mortar plaster to help in controlling the air pollution problem. However, some mix adjustment may be needed to counteract the loss in flow and strength due to the inclusion of TiO2 powder.
|
