Combined Effect of Photocatalyst, Superplasticizer, and Glass Fiber on the Photocatalytic Activity and Technical Parameters of Gypsum

New Method for Photoactive Cement Preparation-Selected Mechanical Properties and Photocatalytic Activity of New Materials

In this study, a new method of obtaining photoactive cements is presented. The goal was to obtain photoactive cements using a method that could reduce the production costs. In the study, an intermediate product from the production of titanium dioxide using the sulfate method, taken from the installation before the calcination process, was used to obtain photoactive cements. Laboratory conditions corresponding to introducing this amorphous TiO2 into cement clinker during its cooling were simulated. The study shows that the temperature from 300 to 800 °C and the time of amorphous TiO2 contact with the cement clinker within 30 min is sufficient to obtain a photoactive cement. The highest photocatalytic activity was obtained for the material with 5 wt.% TiO2 content, and the method used did not cause a significant decrease in the bending and compressive strength of the new photoactive cements. The obtained materials were characterized by determining the crystal size of the TiO2, the sulfur content and the photocatalytic activity during NO decomposition under UV radiation. The bending and compressive strength were measured. The influence of the addition of photocatalysts on the beginning and end of the setting time was also investigated.

Photoactive Cements: A Review

This article presents a short overview of modified cements with photocatalytic activity. First, the types and three main methods of obtaining photoactive cements are presented. The most frequently used modification method is the incorporation of a photocatalyst into the total mass of the cement. The second group analyzed is cements obtained by applying a thin layer of photoactive materials, e.g., paints, enamels, or TiO₂ suspensions, using various techniques. The third group is cement mortars with a thick layer of photoactive concrete on the top. In addition, methods for determining the photoactivity of cement composites, mechanical properties, and physicochemical parameters of such materials are briefly presented. Finally, examples of investments with the use of photoactive cements and development prospects are shown.