Hydrophobic and durable mortar

The durability of cement-based materials such as mortar and concrete typically suffers from water penetration, resulting in corrosion of steel structures embedded inside the material and therefore to damage and weakness of the building structure. Several techniques and approaches have been developed to minimize the ingress of water in an attempt to increase the lifetime ans thus lower the environmantal impact of cementious structures.

Here a mortar hybrid material is presented where a bacterial biofilm is supplemented, increasing the hydrophobic properties. Bacterial biofilms are ubiquitous communities of bacteria encased in a matrix of self-produced biopolymers. In such a biofilm matrix, the bacteria are able to resist various environmental challenges, e.g., chemicals, desiccation, or removal from surfaces. By adding defined dosages of cement substitutes (SCMs), the mechanical strength of the mortar material can be significantly improved without losing the hydrophobic effect of the biofilm. Furthermore the formulation is highly resistant to sulphate attack.