Durability of autoclaved aerated concrete—if carbonation is really dangerous? Facts and myths

Abstract

AbstractAutoclaved aerated concrete (AAC) is used as one of the most popular building materials for many years. The first production unit using an autoclaving process began in 1927. Since then, millions of cubic meters of this material have been produced around the world. Production technologies have been developed in different countries using the production process and available raw materials such as sand, siliceous fly ash from burning coal with and without biomass, or slag. Over 90 years of experience has proved that AAC is a universal and durable material. A few publications have shown negative influence of carbon dioxide on calcium silicate hydrates stability (C‐S‐H, tobermorite), which are present in most of available building materials, such as construction concrete, silicate, or AAC. The influence of carbon dioxide on durability, phase composition, and properties of AAC is tested in a research area. The influence of CO2 has been tested in natural conditions as in artificial weathering. In this work, density, compressive strength, lambda values, shrinkage, and phase composition were tested.