Исследование рациональных видов легких бетонов для наружных стен в условиях жаркого климата
Investigation of rational types of light concrete for external walls in conditions of hot climate
R. R. Hoshim
2018
Vestnik MGSU
A B ST R ACT Introduction. The paper presents theoretical and experimental studies of the improvement of the structure of lightweight concrete, which provides the maximum value of the attenuation of the amplitude of external air temperature fluctuations during the passage of heat flow through the walls and the reduction of thermal conductivity, the results of the 3-factor experiment on determining the rational structure of claydite concrete and the methods for their processing. To determine the
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... purposeful structure of the composition of lightweight concrete and its thermal conductivity, a complex of research works was carried out at the Central Research Institute for Housing, applied to lightweight concrete for exterior walls. The main optimization criterion was the maximum reduction in thermal conductivity while providing the necessary strength, durability and waterproofness. The purpose of this work is theoretical research and experimental substantiation of methods for improving the structure of lightweight concrete used for a hot climate with improved functional performance. Materials and methods. As material a claydite gravel with bulk density p = 400 kg/m 3 of Lianozovsky plant (Moscow) was used, at a ratio of 40 % of the fraction 5-10 mm and 60 % of the fraction 10-20 mm and a Portland cement of the brand "400" of the Voskresensky plant, not plasticized. The water flow rate was varied for 10 seconds, to ensure the mixture to be vibropacked.As a foam generating agent and plasticizer, the "Saponified wood resin" (SDO) was used in a 5 % aqueous solution. The methods were adopted in accordance with the Recommendation on the technology of factory production and quality control of lightweight concrete and large-panel constructions of residential buildings. M. CNIIEP dwelling, 1980. In the department of the lightweight concrete application at CNIIEP of dwelling, a method for the purposeful formation of the structure and composition of lightweight concrete, which provides a set of physic-technical, technological and technicaleconomic requirements, was developed. Results. Calculations are reduced to obtaining mathematical models of dependence of strength R, density ρ, thermai conductivity λ and other indicators of concrete characteristics from initial factors in the form of regression equations. Based on the equations obtained, it was possible to determine the expedient composition of lightweight concrete, which, in combination with the operational characteristics, provides comparable results of the technical and economic characteristics of a singlelayer structure from the projected type of lightweight concrete. Conclusions. 1. An improved composition of the structural and heat insulating lightweight concrete for the load-bearing part of the structure, providing its high thermal stability by chemical additives and low consumption of porous sand, was developed. An algorithm for selecting its composition on computer is made. 2. The conducted researches in the field of design of external enclosing structures for hot climate conditions have shown that: single-layer exterior wall constructions with massiveness of D ≤ 4 provide minimum allowable values of heat flux attenuation and temperature fluctuation amplitude on the inner wall surface. Исследование рациональных видов легких бетонов для наружных стен в условиях жаркого климата Х.Р. Рузиев Бухарский инженерно-технологический институт (БИТИ), 200100, г. Бухара, ул. К. Муртазаева, д. 15, Узбекистан А ННОТА Ц И Я Введение. Представлен подход к усовершенствованию структуры легкого бетона, обеспечивающей максимальное значение затухания амплитуды колебаний температуры наружного воздуха при прохождении теплового потока через стены и снижение теплопроводности, результаты трехфакторного эксперимента по определению рациональной структуры керамзитобетона и методы их обработки. Для определения целенаправленной структуры состава легкого бетона и его теплопроводности в ЦНИИЭП жилища был проведен комплекс научно-исследовательских работ, применительно к легкому бетону для наружных стен основным критерием оптимизации являлось максимальное снижение теплопроводности при обеспечении необходимой прочности, долговечности и водонепроницаемости. Hoshim R. Ruziev A b o u t t h e A u t h o r : Hoshim R. Ruziev -Candidate of Technical Sciences, Associate Professor, Chair,
doi:10.22227/1997-0935.2018.10.1211-1219
fatcat:zdk7ozimandvjgfu5gvrqdgxoy