A simple method to create hydrophobic mortar using bacteria grown in liquid cultures

The ingress of water-soluble aggressive species is a major cause to the reduced service life concrete structures. Bulk modification by adding hydrophobic agents in cementitious materials commonly applied reduce water penetration into matrix. However, conventional modifications are associated with several unresolved drawbacks such as high cost and toxicity. Here, we investigate impact safe easy-to-culture bacteria on properties concrete. We demonstrate that can be conveniently created using liquid culture without need growing biofilms suggested previous research, even strain does not present innate hydrophobicity. These key findings greatly improve feasibility for large-scale application resistance materials. Scanning electron microscopy X-ray diffraction analyses indicated higher levels micro-calcite formations increased addition bacteria. structures account dramatic increase surface roughness which leads elevated hybrid This phenomenon reminiscent “lotus-leaf effect”, ultrahydrophobicity arising from nano- microscopic topologies surfaces. Bacteria-modified cement presents distinct heat-flow profiles during hydration consistent calcite formation. Taken together, this research gives unprecedented mechanistic insight design microbial-modified particularly useful floating offshore Given large repertoire still used, our work sets stage future microbial-based tailored additional functions self-healing odor removal.