Abstract: The invention provides a process for the bio-based reparation of a concrete element having an element surface with cavities, comprising applying a first liquid with a first composition and a second liquid with a second composition to the element surface of the concrete element to provide a combined product to the cavities, wherein the first composition and the second composition are selected to provide gel formation in the cavities after application of one or more of the first liquid and the second liquid to the element surface, wherein the first composition and the second composition are also selected to provide bacterial material, a calcium source, and a nutrient for bacteria in the cavities after application of the first liquid and the second liquid to the element surface, wherein the first liquid at least comprises sodium silicate and wherein the second liquid at least comprises the calcium source.