Non-autoclaved aerated concrete with a modified carbonate-sulfate additive based on soda ash production waste

Abstract

The article considers the technology for producing non-autoclaved aerated concrete using a modified carbonate-sulfate additive prepared from the solid sludge fraction of soda ash production waste. The distinctive feature of the proposed development is the preliminary preparation of technogenic raw material, including separation of the liquid phase, washing from water-soluble chlorides, carbonation, drying, fine grinding, and mechanochemical activation. It has been established that such treatment reduces the negative influence of soluble salts, stabilizes the alkalinity of the additive, improves the uniformity of gas formation, and densifies the interpore partitions of the cement matrix. The developed non-autoclaved aerated concrete with an average density of D500–D600 is characterized by compressive strength of 2.75–4.65 MPa, reduced water absorption, and lower shrinkage. The proposed technology makes it possible to use local technogenic raw materials, reduce energy consumption by eliminating autoclave treatment, and improve the resource efficiency of cellular concrete production.