The Bio-inspired Restoration of Aged Concrete Edifices (BRACE) program aims to prolong the serviceability of Department of Defense (DoD) structures and airfield pavements by integrating a self-repair capability into existing concrete. The DoD relies on steel-reinforced concrete structures such as missile silos and naval piers that are many decades old, not easily replaced, and subject to cracking and corrosive deterioration. The DoD also relies on concrete airfield pavements in expeditionary settings, which are vulnerable to damage from overuse or attack and require rapid repair under logistically challenged circumstances. Unfortunately, state-of-the-art approaches to maintain concrete are one-time interventions, limited to remediation of defects at or near the surface, and typically necessitate down-time for critical assets. No current technology provides ongoing crack repair and prevention for defects deep inside existing aged concrete or prolonged repair of damaged airfield pavements. Inspired by vascular systems that support repair in multicellular organisms and ecosystems, the BRACE program will develop bio-inspired approaches that 1) integrate deep within aged concrete to form a healing “vasculature” for ongoing damage repair; and 2) combine with new concrete to increase the durability of runway patch repairs. To achieve these goals, BRACE performers will engineer and operationalize vascularizing effectors for both longterm (e.g., steel-reinforced marine or buried infrastructure) and rapid (e.g., expeditionary airfield) use cases
Deadlines:
o Proposal Abstract Due Date and Time: April 29, 2022; 4:00pm EST
o Full Proposal Due Date and Time: June 17, 2022; 4:00pm EST
Technical Area 1 (TA1): Engineer Vascularizing Effectors: The overall goal of TA1 is to create a bio-inspired vascularizing effector that will improve existing concrete durability by implementing an ongoing repair capability. Accordingly, TA1 will harness recent advances to address three key challenges: Vascularization, Crack Repair, and QC Diagnostics.
Technical Area 2 (TA2): Operationalize Vascularizing Effectors: The overall goal of TA2 is to develop approaches for operationalizing TA1 vascularizing effectors, so they are easy to adopt and deploy and provide well-characterized service life extension. Performers will develop TA2 technologies in concert with TA1 to ensure design constraints imposed by operational considerations inform the development of the vascularizing. Over the course of the program, performers will develop techniques to apply, characterize, and model vascularizing effectors on specimens of increasing size and complexity, approaching structural and operational realism by the program’s end. Accordingly, TA2 will address three key challenges in deploying a valid, ongoing repair capability: Applying and Maintaining Function, Testbeds for Vascularized Material, and Performance Assessment for Vascularized Structures.