Biotechnological Admixtures for Cement and Mortars

Abstract

Functional biopolymers of cell are proteins, RNA and DNA, which are fast producing and biodegrading. Energy storage polysaccharides, polyhydroxyalkanoates, as well as lipids are producing and degraded slower. Structural biopolymers are cellulose, hemicellulose, chitin of cell wall, and polysaccharides of cell wall and capsule, biodegrading slowly. Microbial extracellular polysaccharides are widely using in cement- and gypsum-based materials to improve such properties of the material as plasticity, water retention, adhesion, shrinkage reduction, flow ability, and stability. Probably, the biopolymers of sewage sludge and activated sludge wastes can be used as the cement admixtures, because several million tons of these materials are available as wastes. Production of polysaccharide admixtures could be more sustainable if it will be performed on the biorefinery. The common products of any fermentation on biorefinery or pyrolytic transformation of wood to fuel—ethanol, acetic acid, and hydrogen—are the most useful substances for the production of biocements, biogrouts, bioplastics, and polysaccharide admixtures. Ethanol is one of the best sources of carbon and energy for the production of polysaccharide admixtures.