Microbial mineralization in cementitious materials: Impact on self-healing and durability

• Applicant: Professor Dr.-Ing. Thomas A. Bier
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 445696912

The here described research proposal investigates the biogenic mineralisation of cementitious systems. The project focusses firstly on the selection of the most suitable microbes, which includes a good resistance against alkaline environments. These experiments will be conducted in cementitious suspensions. In the next step, the impact these microbes have on self-healing abilities as well as on the durability of cementitious samples is investigated in hardened cement pastes and in mortars. In cooperation with our Japanese partners from the Tokyo University of Marine Science and Technology, a selection of microbes is performed using two separate investigation techniques. In the next step, the self-healing abilities of mortar and hardened cement paste samples with four different cement types, are analyzed using optical microscopy as well as a characterization of microstructure through phase analysis and porosity. Included in this analytical step, is the testing of mechanical properties. Additionally, the durability of samples in investigated using a selection of harsh environments including freeze-thaw resistance and exposition in acidic and salt solutions. Conclusions regarding the suitability of different microbe types for crack-healing are expected, resulting in a contribution to sustainability through improved durability.

• DFG Programme: Research Grants
• International Connection: Japan
• Co-Investigator: Dr. Eva Kränzlein
• Cooperation Partner: Professorin Dr. Hiroko Makita