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13PHILOLOGICAL SCIENCES
MEASURES TO ENSURE THE DURABILITY OF CONCRETE STRUCTURES IN SALINE AND HARSH CONTINENTAL CLIMATES OF UZBEKISTAN
Matnazarov I.
Urgench State University, Urgench
Abstract
This article discusses the local preparation of concrete and reinforced concrete structures, which form the core of the modern construction industry, and measures to protect it from external adverse effects, which shortens its service life. The author discusses important measures to increase the service life of reinforced concrete structures in local aggressive conditions.
Keywords: construction, concrete, reinforced concrete, carcass, building material, durability, and salinity.
Introduction
It is well known that, as long as humanity lives, it will certainly continue to be creative. She is constantly looking for tomorrow to be better, more beautiful and fuller than today. It is hard to imagine his future without construction.
The modern construction industry is developing day by day, the construction industry in general is making great strides in the production of building materials, products and structures. The variety of construction materials is getting richer day by day.
Their properties and characteristics have improved, their service life has increased, their quality has increased, and their use has expanded. Of course, the limit of the service life of a building or structure under construction is directly related to the service life of the structural elements that make up the building, in general, all the details. Therefore, at a time of intensive development in all areas, it is impossible to carry out construction work without taking into account the factors that directly affect the service life of materials, structures and items used in construction.
One of the endemic factors directly affecting the longevity of construction materials used in construction in the Autonomous Republic of Karakalpakstan and Khorezm region of Uzbekistan with severe continental climate is the salinity of the soil and the relative high level of groundwater and atmospheric salt.
In these two regions, the salinity of groundwater is high, close to the surface and the level is variable. To date, the salts formed in the place of the Aral Sea are released into the atmosphere by the wind, which has a negative impact on many areas and causes the level of salinity in the regions to rise. In such a territorial, more difficult situation, we will have to constantly monitor the level of salinity of raw materials and semi-finished products used in construction and, if necessary, make changes. Take, for example, bricks made from soil in local conditions; If we do not reduce the salt content of the soil to a minimum before making bricks, the salt content of our prepared bricks will continue to have its negative effects even if we use the bricks raw or baked. That is, the salt in the soil boils on the surface of the brick or on the surface of the wall built of it, even on the surface of the decorated wall. Therefore, when using saline soils to obtain a product, it is necessary to
wash the ulur saline and keep the salinity level to a minimum. Under such conditions, saline leaching of the soil should be carried out periodically. Controlling the level of salinity requires a great deal of responsibility and attention from specialists in the preparation of various building mixes, especially in the preparation of concrete and reinforced concrete structures. Because concrete is a complex material with many components. Its binders, coarse and fine aggregates, the salinity of the water indicate the salinity of the concrete. Therefore, during the preparation of concrete, it is necessary to control the level of salinity of the materials included in it, and if the deviation is detected, we must immediately make adjustments to the process. This is one of the important aspects to consider when choosing a concrete composition and preparing a mixture from it.
Concrete and reinforced concrete structures are the most widely used material in modern construction and are the main component of construction (both structurally) and the longevity of buildings and structures - the longevity depends on the longevity of this material.
Materials and discussions
With the availability of pure concrete in the local environment, it is important to ensure that it continues to operate in a harmless environment. Our conditions are different from those of other regions, as the region is surrounded by the Karakum and Kyzylkum deserts. Therefore, the summer in this place is very hot (sometimes 50 degrees and above) and in winter it can be 2030 degrees, sometimes even colder. This means that the difference in temperature during the year can be up to 70 degrees, and the difference in daily temperature can be up to 20-30 degrees. Such a harsh continental climate, groundwater alkaline near the surface and aggressive, the topsoil is strongly saline, the local raw materials (sand, gravel, water) in the concrete are somewhat saline, and the amount of salt in the atmosphere is relatively high. We need to pay more attention to the following in the preparation of concrete and reinforced concrete structures in the natural and climatic conditions.
That is:
- Correct selection of raw materials for concrete;
- determine the level of salinity of large and small fillers and keep them under constant control;
- control the content of water used for the preparation of the mixture;
- During the hardening of the concrete mix, we must ensure that the water that provides its moisture (from the outside) does not contain salts;
- to ensure that salt does not pass through the concrete during the curing process as a result of moisture penetration from the surrounding objects (soil, etc.);
- Strong protection of elements of concrete structures located in the underground part from salts present in the soil, moisture in the underground zone;
- if possible, pre-identify areas with high salinity and use alkaline-resistant binders;
- Ensuring that in the manufacture of concrete and reinforced concrete structures there are no cracks, the protective layer of the reinforcement carcass is maintained in moderation;
- take measures to prevent the collapse of concrete, eliminate the factors that lead to corrosion of reinforcement;
- immediately identify unprotected areas of concrete structures and eliminate deficiencies;
- lifelong maintenance of concrete;
Hence, the long-term durability of concrete structures cannot be defined and determined by a single general indicator (criterion). Also, the compressive strength limit of concrete does not appear to be a sufficient indicator of its durability.
In conclusion, the following can be considered as additional measures to further increase the service life of concrete structures in local conditions;
- its problems of frost resistance, resistance to aggressive solutions, resistance to adverse atmospheric
influences, resistance to biological influences, resistance to carbonation and chloride-containing substances. It is also possible to strengthen the durability of concrete structures by the following important measures taken during the preparation of its compound;
- selection of mosquito fillers;
- intensive mixing to ensure homogeneity during the preparation of the mixture;
- intensive compaction of the mixture during casting;
- take all measures to ensure the convenient placement of the mixture;
- maximum protection of concrete from the effects of alkaline environment;
- In the future, the concrete structure can be achieved by organizing the necessary periodic maintenance.
In short, to ensure the long-term durability of concrete structures, we need to understand the duration of its resistance to external and internal influences during the service life of reinforced concrete structures and products.
References
1. Akramov Kh.A. "Design of enterprises of the construction materials industry." T. Uzbekistan, 2003
2. Bajenov Yu.M., Komar A.G. "Technology of concrete and reinforced concrete products". M. Stroyiz-dat, 1984
3. UzRST679-96 «Concrete. Pravila podbora betona».
4. UzRST 7473-94. "Mixed concrete"
RESEARCH OUTCOMES AND RECOMMENDATIONS ON CREATING ETYMOLOGICAL
DICTIONARY
Rakhimova G.,
Senior lecturer, Urgench State University, Uzbekistan
Yuldashev E.
English teacher, Urgench State University, Uzbekistan
Abstract
This article analyses about etymological dictionaries and some recommendations how to create them. Collected word origins from the etymological dictionary of English language have been divided into the thematic groups; analyzing different approaches and principles on creating etymological dictionaries, comparing them in different languages. According to this similarities and differences between them have been analyzed on the basis of lexical, semantic, lingua-cultural features.
Keywords: etymology, lingua-cultural features. recommendations, compare, word and phrase, dictionary, thematic groups.
Introduction
Today the English language is widely spoken throughout the world. It is the language of 21st century the language of informative technologies, so while describing the English language; first of all, it should be underlined that the English language is the mother tongue of the global media. To understand English clearly one should know not only its standard vocabulary but also its different styles, dialects, proverbs, sayings, phrasal verbs and idioms, as they used in any sphere: books, films, newspapers, formal speeches.
One, looking through some papers, magazines and journals, will discover the same language to sound quite different, because he will find familiar words with unfamiliar meanings. He will face idioms, phrasal verbs etc. In this case etymology of the words are vital to learn.
We have studied different etymological dictionaries done by different linguists. Such as Historical etymological dictionary of modern English written by M.M. Makovskiy, "Origins" written by Edric Patridge, Word and phrase origins by Robert Hendrikson, and
