Moisture behavior calculation of single-layer enclosing structure by means of discrete-continuous method

Vladimir G Gagarin ,Vadim Akhmetov ,Kirill Zubarev

doi:10.1051/matecconf/201817003014

Vladimir G Gagarin , Vadim Akhmetov + Show 1 more

Open Access

https://doi.org/10.1051/matecconf/201817003014

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Abstract

The paper proposes mathematical model for unsteady-state moisture behaviour calculation of single-layer enclosing structures by means of moisture potential and discrete-continuous method. A formula for moisture potential value calculation for single-layer enclosing structure in any enclosing structure section, at any moment of time, under continuous control for temperature distribution, has been derived. Moisture transfer between the enclosing structure and ambient air is taken into account by means of third-kind boundary conditions. Temperature distribution is taken as constant during a month. The proposed method allows for moisture potential determination according to the proposed formula for every month. Calculation results obtained by the proposed method, well-known unsteady-state method and engineering method developed by V.G. Gagarin and V.V.Kozlov have been compared for single-layer enclosing structure made of aerated concrete. It was shown that average value calculation results disagreement does not exceed 7% for the proposed method and unsteady-state method. However, the proposed approach allows for moisture distribution determination using analytical expression, which is convenient for use in engineering practice.

Highlights

Moisture behavior researches are actual at present
Moisture flow is represented as a sum of liquid and vapor moisture flows within this model: gto t gv gL
Inside air temperature 22 ͦС and relative air humidity 60 % have been maintained constant in the building

Summary

Introduction

Moisture behavior researches are actual at present. Errors in moisture behavior assessment can result in reduction of enclosing structure durability [5,6,7,8]. One of the most important research problem is to develop calculation methods for enclosing structure moisture condition [9,10,11,12] and further theoretical results checkup by means of field studies [13, 14] and laboratory experiments [15, 16]. Gagarin’s mathematical model [17] is well-known. Moisture flow is represented as a sum of liquid and vapor moisture flows within this model: gto t gv gL

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