Elrefaei A.E.M.M.

Phd of engineering, Construction department, Egyptian Russian University, Egypt

Functionalization of one-component cement silicate paint

https://doi.org/10.58224/2618-7183-2024-7-5-5
Аннотация
The paper presents the results of a study devoted to expanding the functional properties of one-component cement-silicate paints based on white Portland cement, soluble sodium glass and a hardening retarder (sodium phosphate). Existing compositions, despite their exceptional performance qualities, are not able to provide the entire range of required functional characteristics. Therefore, in order to expand the areas of cement silicate paints application, additives based on aluminum powder and nano-sized titanium dioxide were introduced into the coating composition. This resulted in the increase in the electrical conductivity of the coating and made the paint self-cleaning due to photocatalysis.
The study showed that the introduction of nano-sized titanium dioxide particles into the paint composition provides the rapid degradation of organic pigments (within 2 days) due to the photocatalysis reaction occurring under the influence of ultraviolet solar radiation. The pigments are further removed due to precipitation. This helps to maintain the aesthetic properties of the paint even in high dust conditions, for example, in conditions of sandstorms, which are frequent in the African climate.
The introduction of aluminum powder into the paint composition reduces its electrical resistance (in a wet state) from 5.05 kOhm for the reference sample to 2.7 kOhm for the modified sample. The thickness of the applied paint was 350 microns. This can help the coating to absorb man-made electromagnetic radiation due to shielding, while preventing the accumulation of static electricity on the surface, which also contributes to less dust in the premises. In addition, the use of aluminum powder instead of traditional electrically conductive carbon-containing additives allows maintaining the aesthetically pleasant white color of the paint.
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Study of the characteristics of pavement elements made of rein-forced soil with the use of secondary resources

https://doi.org/10.58224/2618-7183-2023-6-6-2
Аннотация
The importance of using secondary resources on the basis of industrial waste is understood by both governments of developed countries and business (production of Portland cement using ground metallurgical slag as a mineral additive at Novotroitsk, Magnitogorsk, Sterlitamak, Katav-Ivanovsk and other plants in the South Urals). The use of secondary raw materials requires the creation of technological infrastructure for processing of secondary raw materials, the costs of which can be quickly recouped due to the cheapness and availability of industrial secondary raw materials and freeing the territory from environmental pollution. In order to recoup the costs of the infrastructure, it is necessary to guarantee full compliance of the quality of pavement elements with the requirements of GOST R 59120-2021. Secondary raw materials have a great variety and laboratory analysis of the quality of pavement elements is required in order to design compositions with the best quality, satisfy-ing all regulatory requirements. In our work the authors present the results of laboratory research and evaluation of the possibility of using clinker-free lime-slag binder based on the mineral product of so-da production and metallurgical slags to strengthen and stabilize soils for their use in pavement struc-tures in the construction of roads for various purposes and climatic zones.
It is experimentally shown that the addition of lime-slag binder in the amount of 8-10% of the dry weight of both cohesive (loamy soil, loamy sand) and non-cohesive (fine sand) soil allows to obtain reinforced soil with improved strength and elastic-deformative characteristics, which can be used in-stead of scarce natural crushed stone and gravel in the construction of underlying layers of pavements in the construction and reconstruction of highways. This technology can be used not only in the Rus-sian Federation, but also in a number of other countries, including those with hot dry climates (e.g., the Republic of Egypt).
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