CONCRETE

[:ru]Гагарин В. Г.[:en]Gagarin, V.G.[:] [:ru]зав. лабораторией строительной теплофизики Научно-исследовательского института строительной физики Российской академии архитектуры и строительных наук (ФГБУ НИИСФ РААСН), зав. кафедрой отопления и вентиляции Московского государственного строительного университета (ФГБОУ ВО НИУ МГСУ), доктор технических наук, профессор, член-корреспондент РААСН, Москва, Россия[:en]Head of Building Thermophysics Laboratory at the Research Institute of Building Physics of the Russian Academy of Architecture and Construction Sciences (NIISF RAASN), Head of Heating and Ventilation Department at the Moscow State University of Civil Engineering (MGSU), Dr. Eng. Sc. (Eng.), Professor, Corresponding Member of RAASN; Moscow, Russia[:]

[:ru]Козлов В. В.[:en]Kozlov, V. V.[:] [:ru]канд. техн. наук, вед. науч. сотрудник, Научно-исследовательский институт строительной физики РААСН, Москва, Россия[:en]Cand. Eng. Sc., Senior Research Fellow, Scientific Research Institute of Construction Physics of Russian Academy of Architecture and Construction Sciences, Moscow, Russia[:]

Alitinform №1 (13) 2010 г. 52-59 p.

Abstract

Currently known methods of engineering calculation or estimation of moisture conditions of walling take into account moisture movements in a form of vapor only. These methods were developed in the USSR in late 1920s and in the Federal Republic of Germany in late 1950s. The share of liquid moisture transfer in modern walling with the use of aerated concrete, known as those with higher level of heat insulation, increases because of lower temperature gradient and, therefore, lower gradient of water vapor partial pressure. It has been suggested to introduce a function, called «potential F», in order to take into account the summarized transfer of vapor and liquid moisture. Introduction of this function enabled us to considerably simplify equation of moisture transfer, and to solve it using mathematical methods. Potential F is calculated based on parameters that are traditionally applicable to building materials and included into reference books, such as water vapor sorption isotherms, coefficients of vapor permeability and hydraulic conductivity. These parameters have been determined for some super-light concretes, and then used as a basis for calculating dependence of potential F on moisture content and temperature. Calculations of moisture condition of walls made from aerated concrete blocks have been taken as an example demonstrating opportunities offered by the considered method.