A New Preparation Method of Cement with Photocatalytic Activity

Abstract

The studies of some mechanical properties and photocatalytic activity of new cements with photocatalytic activity are presented. The new building materials were obtained by addition of semi-product from titanium white production. Semi-product was calcined at 300 and 600 °C for one, three, and five hours and then this material was added to cement matrix in an amount of 1 and 3 wt.%. New materials were characterized by measuring the flexural and compressive strength and the initial and the final setting time. The photocatalytic activity was tested during NOx photooxidation. The cement with photocatalytic activity was also characterized by sulphur content measurements. The measurement of reflectance percentage of TiO2-loaded cements in comparison with pristine cement and TiO2 photocatalyst calcined at 600 °C were also performed. It should be emphasized that although in some cases, the addition of photocatalyst reduced the flexural and the compressive strength of the modified cements, these values were still within the norm PN-EN 197-1:2012. It was also found that the initial and the final setting time is connected with the crystal size of anatase, and the presence of larger crystals significantly delays of the setting time. This was probably caused by a water adsorption on the surface of anatase crystals.

Photoactive Cements: A Review

“…There are many literature reports on the excellent properties of cement materials, such as air purification [ 3 , 7 , 16 , 17 , 19 , 23 , 24 , 104 , 105 ], self-cleaning [ 6 , 8 , 12 , 25 , 32 , 37 , 38 , 39 , 40 , 106 ], and self-sterilization [ 4 , 62 , 103 ]. However, despite many advantages, the wide application of photocatalytic technology in civil engineering practice is still limited [ 28 ].…”

“…Wang et al [ 130 ] showed that the addition of NT reduces the initial setting time by about 40 min, from 190 min for cement without NT addition to about 150 min for cement with 5 wt% TiO 2 . On the other hand, Janus et al [ 104 ] reported that the addition of an intermediate from the production of titanium white with the sulfate method, in the amount of 1 and 3 wt.% modified at 300 °C slightly increases the initial and final setting time compared to unmodified cement, on average by 30 min initially and the final one by about 50 min. On the other hand, for TiO 2 modified at 600 °C, the initial one was on average 40 min longer, and the final one was about 70 min longer.…”

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

“…In our previous work [3], the NO gas (1.989 ppm ± 0.040 ppm, Air Liquide, Kraków, Poland) was used as model pollution in photocatalytic tests. NOx removal was evaluated using the experimental installation, a scheme of which is presented in Figure 1.…”

“…Currently, an important argument in favor of its use is the contribution to protecting the natural environment [1,2]. TiO 2 is a photocatalyst that is often added to various types of building materials, such as glass, cement, gypsum and others, in order to give them self-cleaning properties, as well as to make them able to clean the air from pollutants [3,4]. We can distinguish three main methods of obtaining photoactive building materials.…”

Transfer of a Photocatalytically Active TiO2 Nanotube Array onto Cementitious Materials

“…TiO 2 nanoparticles are added to the concrete mix and therefore are incorporated within the bulk material. Only a fraction of those particles is allocated at the material–atmosphere interface and hence can be exposed to light to undergo photocatalytic reactions. − Often an enhancement of mechanical properties by influencing the hydration mechanism of clinker phases is targeted and achieved as well …”