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21PROSPECTS FOR THE PRODUCTION OF WALL MATERIALS FROM
ARBOLITE IN UZBEKISTAN
Baqitjan Kudaybergenovich Ibrohim Numanovich A. S. Nazirov
Sarsenbayev Abdullayev
Doctor of Technical And Fergana Polytechnic Fergana Polytechnic
Technical Education, Institute Institute
M.Auezov SKSU
ABSTRACT
The article deals with the advantages of developing a technology of energy-efficient wall materials made of arbolite in Uzbekistan, as well as the expansion of this material in construction. Using stalks of local cotton instead of wood chips, which are the main raw material for arbolite.
Keywords: arbolite, cement, organic fillers, chemical additives, arbolite panels, environmentally friendly material, biohasticity, frost resistance, soundproofing, efficiency.
Currently, the need for new building materials in the country is growing day by day, which, in turn, requires the improvement of the construction materials industry, the use of new materials in construction.
The Resolution of the President of the Republic of Uzbekistan PP 4335 of May 23, 2019 "On additional measures for the accelerated development of the construction materials industry" provides for the cardinal development of the construction materials industry, namely, taking into account the development and implementation of modern energy-efficient environmentally friendly and in all respects safe innovative developments in this industry. As such materials, you can take arbolite. Arbolite-light concrete based on cement binder, organic aggregates (up to 80-90% of the volume) and chemical additives.
Currently, there are about 12.5 thousand enterprises for the production of building materials in Uzbekistan, the number of types of which has exceeded 180. 626 international standards for the production of high-quality and safe building materials have been adopted [1]. However, insufficient attention is paid to the study and production of arbolite in the republic.
Arbolite is a combination of crushed wood and specially prepared high-grade cement. This building material is characterized by high strength and biohasticity, low thermal conductivity, high fire resistance.
Arbolite today is one of the most unique building materials. Its uniqueness lies in the fact that in arbolite for the first time it was possible not only to combine the strength,
fireproofness of concrete and the amazing microclimate of a wooden house (arbolite is 80-90% wood chips), but also as a bonus to obtain a material with high thermal insulation ability. And in our time, when there is a constant increase in the cost of energy, the insulating properties of the material become one of the main advantages of arbolite [2].
When building a house, questions often arise: how to save on building and finishing materials and speed up the construction process. An excellent solution is to build a house from arbolite panels.
Arbolite panels - made of environmentally friendly material, have excellent, thermal and sound insulation properties, as well as good air exchange. Arbolite is a combination of crushed wood and specially prepared high-grade cement. This building material is characterized by high strength and biostoicence, low thermal conductivity, high fire resistance [3].
The use of arbolite panels in various areas of construction - residential premises, industrial buildings, agricultural buildings, etc., is possible due to the technical properties of the material. Safety and environmental friendliness - arbolite is made of environmentally friendly materials, when used and further operation, it does not emit toxic substances. Strength and flexibility - the material is strong enough, the maximum indicator is 3.5 MPa. Due to the sawdust included in the composition, arbolite plates withstand shock loads well and have a bending strength index of 0.7 - 1 MPa. Arbolite is resistant to mold and fungal diseases, wood components at the preparation stage are treated with antiseptics. Weight and geometry of the product - a small weight of the plates does not require a deep reinforced foundation. Plates are manufactured at the factory and cut on automatic equipment, so the lines and corners are straight, there are no chips and irregularities [5].
The advantages of panels in the construction market are many varieties of panels and blocks for the construction of buildings, each of them have their positive and negative features. So what is better - arbolite or, for example, sip panels? Of course arbolite and here's why. The main advantages of arbolite plates: Speed - one floor is built in 24 days; Durability; Thermal insulation - plates retain heat well, they can be safely attributed to thermal panels, they do not require additional insulation of the walls. Also, the plates are large, so the connecting seams, which means "cold bridges" are less [6]
Economy - the material is in an affordable price category, its weight does not require overexpenditure during transportation, it also does not crack and is not subject to chipping during transportation, so no additional stock is required for the "battle".
You can also save on insulation and sound insulation, since these indicators are at arbolite at a height. And also on the adhesive solution - the dimensions of the plates are large, the seams are small.
Arbolite panels are load-bearing, so the installation of an additional frame during construction will not be needed.
Versatility - from this material you can build buildings of various directions -residential buildings, industrial buildings, garages, fences of the adjacent territory, outbuildings, etc.
Easy operation - installation is fast, the panels are connected to each other through a fastening system, easy to process;
Arbolite can be used in any climatic zones and conditions, construction is possible at any time of the year.
Ecological wall panels made of arbolite are a universal material for the construction of premises of various functionality. Arbolite belongs to the group of light concretes and has a large list of advantages, for example, high heat and sound insulation. Arbolite is made on the basis of wood chips and cement mortar. Chips before use are thoroughly dried and processed with various compositions that will prevent rotting and reduce the hygroscopicity of the finished product [4]
Composition and proportions of arbolite components:
• Sawdust - 55% by weight;
• Portland cement M400 - 12%;
• Sand purified from foreign impurities - 26%;
• Water - 7%;
• Slaked lime.
Based on the above data, it should be noted that good conditions for the production of arbolite have been created in Uzbekistan. An example is cement plants in Uzbekistan.
In January-December 2020, enterprises of the Republic of Uzbekistan produced 12.54 million tons of cement, which is 14% more than in January-December 2019. The volume of clinker production for the same period increased by 8.9% and amounted to 10.03 million tons. Cement production has maintained growth, including through the implementation of large investment projects with the participation of foreign investments.
Cement consumption in the country for 12 months of 2020 amounted to 14.52 million tons.
The leader in terms of production in the Republic of Uzbekistan in 2020 is the Kyzylkumcement plant, which produced 3.69 million tons of cement (1.5% more by 2019) and 2.91 million tons of clinker (1.5% less by 2019).
The volume of cement exports from Uzbekistan amounted to 530.3 thousand
tons.
To date, 30 specialized enterprises are engaged in the production of cement, among which the largest are Kizilkumcement, Akhangarancement, Kuvasaycement,
Bekabadcement and Almalyk Mining and Metallurgical Combine. The total design capacity of cement enterprises of Uzbekistan is more than 12 million tons of cement per year.
According to the indicators, it is known that cement, which is the main raw material for arbolite, is enough in Uzbekistan.
The second component is chips and sawdust. Although it is known that there are not enough wood resources in the republic, it is possible to conduct research on the use of cotton stalks, wild shrubs and coarse grasses in this capacity.
Uzbekistan, one of the world's largest cotton producers, harvested 3.8 million tons of cotton this year, which is 9 per th. more than last year, the Ministry of Agriculture of the Republic reported on Tuesday.
According to world experience, arbolite is now widely used mainly in the Russian Federation. One of the main reasons for this is the large amount of wood chips in Russia. We all know that the demand for wood in our country is very high. 55% of the property of arbolite is wood chips, and to solve this problem, it is proposed to use cotton stalks instead of chips.
The study of the influence of the fraction of crushed cotton stems showed that the use of aggregates with a high content of small fractions in the composition of slag arbolite increases the density of arbolite, but its strength remains relatively low: at the age of 28 - 1.5 MPa.
The use of crushed cotton stems with a significant content of large fractions in the composition of slag arbolite, where there are oches (21-30% by weight of the stems), worsens the miscibility of the molded mixture.
At the same time, lumps of oches are formed, which makes it difficult to obtain a homogeneous mass by volume, and also increases the sealing coefficient and specific pressure of pressing. The latter leads to the production of arbolite of relatively low strength, (at 28-day age - 0.9 MPa) and complication of the technology of preparation of the material.
A decrease in the strength of arbolite is also due to the fact that when grinding cotton stems, the bark is not completely separated from the trunk and thereby reduces the adhesion of the slag-alkaline binder to the trunk.
Large fractions and long oches, having a low density, with an equal consumption of aggregate per unit volume of slag arbolite require more pressure to seal (mold) the mixture, so the elastic deformation (relaxation) of arbolite ends in more than 24 hours, which requires a long content of products in the form. This leads to a decrease in the turnover of forms and a change in the geometric shapes of products due to unquesped stresses of the structure of slag-alkali arbolite. An increase in the specific pressure of pressing more than 0.6-0.7 MPa leads to the release of moisture in compositions 3, 4 and 7. Thus, the composition of 7 released moisture more than 80kg per 1 m 3 of the
mixture at a specific pressing pressure of 1.0-1.2 MPa. The presence of cotton residues (8% by weight) in the aggregate led to clunking of the mixture during stirring.
This is due to the larger specific surface of cotton, which, intertwined with the stems (due to friction forces), forms lumps. Lumps reduce the homogeneity of the mixture, which negatively affects the strength properties of slag-alkalis arbolite [7]
Cotton and oches have a much higher water absorption than stem trunks. The accumulated moisture during soothing does not flow under normal conditions, i.e. without an additional technological event. Its removal is possible only in a physical way: pressing, vacuuming or drying. A large amount of moisture at the site of accumulation of lumps when sealing the mixture by pressing leads to the fact that squeezed moisture (lumpy) carries with it astringent milk and additives, and pores are formed in hardened arbolite. All this leads to a large consumption of binders and additives, complicates the technological process [8]
Crushed cotton stalks obtained by using sieves with hole sizes of 15, 20, 28, 1518mm, compared with aggregates obtained on sieves with hole diameters of 10 and 35mm, allow: - to produce slag arbolite products with relatively high strength properties; - save binders; - reduce the density of arbolite; - increase manufacturability or reduce the time to achieve homogeneity of the arbolite mixture; - to obtain the optimal (homogeneous) structure of arbolite. The most optimal fractions for obtaining structural arbolite are crushed cotton stalks obtained by using sieves with hole diameters of 15-18 and 20mm.
At the stage of laboratory research, the properties of local raw materials are studied in order to improve both the material itself and the technology of its production.
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