Effect of Using Nano-TiO2 on the Rheological Properties of Cementitious Systems

Abstract

Self-cleaning concrete (SCC) was developed that can reduce air pollution by utilizing its photocatalytic property. Due to this feature, polluting materials are broken down into H2O and CO2, which are completely harmless, without the need for any additional carrier gas. For this purpose, it was emphasized that semiconductor oxides with photocatalytic properties such as TiO2, ZnO, CdSe and WO3 are used in the production of SCC. Compared to other oxides, it was determined that nano-TiO2 is more commonly preferred. However, it was emphasized that the use of nano-TiO2 due to the high surface area/volume ratio increases the water requirement and the risk of agglomeration of cementitious systems. This situation directly affects the rheological properties of SCC. In this study, the effects of nano-TiO2 utilization ratio change on the rheological properties of cementitious systems were investigated. For this purpose, a total of 4 mixtures were prepared by substituting nano-TiO2 with 28 nm at a rate of 0, 0.5, 1 and 1.5% by weight of cement. The rheological properties of the prepared mixtures were evaluated according to the dynamic yield stress (DYS), apparent viscosity (AV) and structural build-up (Athix) parameters. It was understood that the DYS, AV and Athix values of the mixtures increased with the increase of nano-TiO2 utilization ratio.