Bacterial Concrete: A Sustainable Building Material with Advantageous Properties

Abstract

Bacterial concrete is concrete in which bacteria are embedded and is a material which exploits the metabolic functions of these specially selected bacteria, genus Bacillus. The bacteria are amalgamated within clay pellets along with the nutrient calcium lactate. When the concrete around the pellet cracks, the pellets break, and the bacteria metabolise the calcium lactate to produce insoluble calcium carbonate, filling cracks up to ~2 mm wide. The addition of the clay pellets and the bacteria to the concrete improves its compressive and tensile strengths, making it better suited for applications where the concrete must endure severe stress. Consequently, the modulus of toughness is improved, though the extent of the improvement depends on the grade of concrete used. Bacterial concrete is industrially advantageous as its low coefficient of permeability and high acid durability factor makes it less prone to corrosion and less likely to require extensive repairs. This is ideal for structures that are difficult or expensive to maintain as well as for use in motorways that endure corrosion from salt used in de-icing. This review will focus on the properties of bacterial concrete and its industrial use. It reveals that despite higher initial costs, the enhanced properties of bacterial concrete compared to conventional concrete, makes it a more sustainable material in the long run with an overall benefit to global carbon emissions.