• What is the problem/issue being addressed?
Research to date has focused on the self-healing process in air or water environments. However, almost all structures (including bridges, buildings, tunnels, dams) are built on or in the ground. Thus, a significant amount of concrete structural elements are exposed to all sorts of ground conditions, e.g. different soil types, groundwater regimes, chemical and bacterial compositions that naturally existed within the ground. Research in this area is necessary because in underground concrete structures, cracks are invisible, surrounded by soil and their location cannot be accessed. This research helped to understand how different complicated ground conditions could influence the bio-self-healing process and whether an adjustment should be adopted by concrete designers.
• Why is it important for society?
The research vision is to reduce the expensive maintenance cost of underground infrastructures by reducing the uncertainty of the design of bio-self-healing concrete used for these structures. Therefore, the outcomes of this research are highly relevant to the construction industry and the knowledge produced by the project will have an economic, financial and societal impact in the EU and other regions.
• What are the overall objectives?
The hypothesis of this research is that the bio-self-healing process can be differently influenced by different ground conditions. Therefore, the project aims to explore the efficiency of the bio-self-healing solution in underground concrete structures. The research combined, in a novel interdisciplinary approach, several methods applied in materials/concrete, geotechnical engineering, and microbiology to conduct a series of lab-scale experiments on mortar specimens incubated within various soil environments. This allowed the investigation of the effect of several factors, including the type of soil, saturation regime and class of (chemical) exposures, on the bio-self-healing process.