On the Physicochemical Nature of the Creep of Autoclaved Aerated Concrete with an Allowance for Carbonization

Abstract

The article touches upon the issue of the assessment of the effect of atmospheric carbon dioxide on the development of creep deformations in autoclaved aerated concrete. The authors carried out the extensive experimental and theoretical studies of creep deformation and its reversibility on prisms with various degrees of carbonization in order to determine the physicochemical nature of the creep of aerated concrete during carbonization. As a result, it was found that the main reason for the increase in creep and reduction of its reversibility for aerated concrete, taking into account its carbonization factor, is the fact that the content of the gel-like part of silica acid increases and the volume of the crystalline part of the solid phase changes. There is an increase in its absolute specific surface; microdamages in the structure of concrete are growing and they are associated with the conversion of hydrated calcium silicate to calcium carbonate.