Moisture conditions of modern structures made of autoclaved aerated concrete in operation period

Building Materials

In Saint-Petersburg and area six organizations making cellular concrete of autoclave hardening operate. At all enterprises the cellular concrete is made by the gas way of pore development by molding technology. The molding technology in practice means that the mass humidity of concrete on an exit from autoclaves will be at level of 35-45 % (great values of humidity correspond to smaller density). The similar situation is observed in other regions: more than 80 % of all autoclave cellular concrete in Russia are made by molding technology. 

The high humidity caused by presence of technological and constructional moisture in an initial stage of operation quickly decreases, reaching gradually operational level. The established humidity of cellular autoclave concrete as a part of protecting walls makes 3–6 % on weight. However the raised humidity of cellular concrete in an operation initial stage causes smaller settlement values of durability of concrete in a laying. Durability of concrete, in turn, influences on bearing capacity of anchorings for ventilated facades, if they are fastened in a body of cellular concrete. 

Thus, the information on dynamics of change of laying humidity in an operation initial stage allows to estimate terms of reach by designs calculated strength and thermophysical parameters.