Evaluation of rheological properties of mortar with TiO2 addition

Abstract

Adding TiO2 tocoating mortars is carried out to promote self-cleaning through photocatalytic activity. However, this addition influences the workability of the mortar and, consequently, the application stage as the TiO2 used can present a large number of fine particles and a high surface area, increasing the demand for mixing water, requiring consistency adjustments before coating. In this work, three mortars (two with the addition of different types of TiO2 and one reference) were developed on a laboratory scale to maintain similar workability, using the flow table test. The amount of kneading water was changed to maintain a spread of 220 ± 10 mm and the content of air-entrained was kept constant, around 25%. The mortars were evaluated using the squeeze flow method. Then, a blind test was performed to assess the mason sensitivity during handling and application of the coating, and all mortars were considered similar. However, the yield of the compositions with TiO2 addition was lower compared to the reference composition, making it possible to explain the results based on the physical parameters of the formulations and with a more in-depth analysis of the rheological indices obtained by the squeeze flow test.