Effect of Equilibrium Moisture Contents on Insulating Performance of Autoclaved Aerated Concrete Blocks

Abstract

In this paper, a research was performed which considers the material characteristics of autoclaved aerated concrete (AAC) blocks and the weather characteristics in Pearl River Delta region. The AAC blocks laws of absorption and desorption and its thermal conductivity under different equilibrium moistures were measured. The experimental results show that equilibrium moisture content (EMC)is 6.27% for AAC blocks with a B07 density in hot and humid areas in the Pearl River Delta region including the city of Guangzhou, and the correction coefficient of the thermal conductivity is 1.5.

Measuring the Thermo-Technical Parameters of Autoclaved Aerated Concrete

“…These results correspond with literary information. Various authors [1,2,3,6,7] indicate linear relation between thermal conductivity and moisture content of the material. However, studies with nonlinear relations are also published [4,5].…”

“…These differences became greater moisture content increased. According to the literature [1,2,3,6,7], the relation between bulk density and thermal conductivity is nonlinear. However, this tendency is clearly indicated only in wide enough spectrum of bulk densities, while the greater curvature is in the area of smaller bulk densities.…”

“…Bulk density is the factor that affects all physical properties of every material, including autoclaved aerated concrete (AAC). There is a plenty of evident that compressive strength rapidly decreases with decreasing of bulk density [1,2,3]. Compressive strength is also affected by moisture content in the material.…”

“…Pore radius is very important for capillary absorption, frost resistance etc. The coefficient of thermal conductivity λ belongs to basic thermo-technical parameters of building materials, including autoclaved aerated concrete (AAC) [1,2,3]. The manufacturers of building materials indicate the value of coefficient thermal conductivity λ usually defined on dried material.…”