This project was a proof-of-concept investigation aimed at developing an innovative fungi-mediated self-healing concrete technology.   Research activities in the initial phase focused on assessing the interactions of fungi with concrete for improving fungi survivability and growth.  Two types of fungi strains with promising healing performance were identified.   Methods to improve the survivability and growth rates of fungi were developed and evaluated. Research in the second phase focused on developing protection strategies such as encapsulation to protect fungi spores to endure mechanical loads during the concrete mixing process and to survive the possible long dormancy period inside the concrete matrix.  A scalable procedure was developed for microcapsule production that allows streamlined large scale production of self-healing microcapsules.  Activities in the final phase involved developing and implementing an experimental protocol to assess the performance of the self-healing agents.  Microcapsules containing fungi-based self-healing agent were introduced into the mortar mixture during the mixing process.   Specimens with different concentrations of self-healing microcapsules were produced.  After a curing period, cracks with a range of widths were generated in the mortar specimens.  The results show that cracks over 1mm in a cement mortar mix were successfully healed with fungi-based healing agents.  In addition, the surface of crack healed with fungi showed strong hydrophobicity, which could help to mitigate concrete deterioration associated with ionic transport into concrete matrix (i.e., deicer ingression, corrosion, etc.) and improve durability. Overall, this proof-of-concept study successfully validated the concept of fungi-based self-healing for concrete and demonstrates its significant potentials for engineering applications. 

The Final Report is available.