Composition and Properties of Fine-grained Concrete for Self-cleaning Coatings

Abstract

The paper considers the dependences of the properties of self-cleaning fine-grained concrete on the composition of the concrete mixture: the ratio of sand to white Portland cement, the content of plasticizer, the content of photocatalytic composite material. The photocatalytic composite material (PCM) is a diatomite-based anatase-silica material obtained by sol-gel deposition of nanoscale TiO2 of anatase modification on a silica carrier. The investigated properties of fine-grained concrete were: average density, compressive strength and self-cleaning ability, which was determined by evaluating the photocatalytic decomposition of an organic dye – Rhodamine B. It was shown that an increase in the content of PCM to increase the ability of the coating to self-cleaning leads to a loosening of the structure of fine-grained concrete, but this can be successfully offset by an increase in the content of plasticizer, which additionally improves the distribution of the photocatalytic agent in the cement-sand matrix. An increase in the proportion of sand and the content of plasticizer also contribute to an increase in the ability to self-cleaning. The pozzolan activity of the PCM provides an increase in the strength of concrete. The results of comparing the self-cleaning ability of fine-grained concrete of various compositions indicate a high photocatalytic activity of samples with PCM, which allows its application for creating self-cleaning coatings.

Multifunctional Anatase–Silica Photocatalytic Material for Cements and Concretes

“…The preparation of the concrete mix for fine-grained concrete and the production of samples were carried out according to a method similar to the method of preparation of cement-sand mortar mentioned in EN 196-1. The composition of the concrete mixture was developed earlier [27] and included the following measurements (consumption in kg per 1 m 3 of the mixture): cement was 278, ASPMs were 33, sand was 1892, plasticizing additive was 5.5, and water was 110 (mass ratios of the components are shown in Table 5). After vibration compaction, the samples were placed in a steam-curing chamber and treated according to the following regime.…”