Current technology for repairing concrete structures requires either replacement of aged concrete-which can be tedious, expensive, and logistically onerous or one-time sealing of defects (e.g., grout injection or healing spray) that do not provide long-term crack repair.
Due to rebar corrosion in reinforced concrete, modern corrosion prevention methods have issues stemming from corrosion inhibitors that require concrete cover replacement and contain toxic solvents. Migrating corrosion inhibitors (MCIs) do not require cover replacement, but have limits on their diffusion. The state-of-the-art bio-inspired approaches are promising but cannot repair both existing and newly formed deep defects in both reinforced and plain concrete with prolonged functions.
LLNL researchers are developing Concrete Assisted by Particles Sealed Under Large-scale Encapsulation (CAPSULE) to provide a solution that utilizes different biological and engineering approaches to repair aging concrete. It uses an innovative method to
- self-heal existing and new cracks in damaged concrete structures down to meters in depth
- effectively transports biological and sensing agents under various concrete environmental conditions
- prevent further damage of concrete structures with steel-corrosion prevention, extending the structure lifetime and reducing the cost and logistics of repairs.
CAPSULE is a vascularizing, crack sealing cement repair agent whose capsules are composed of bio-compatible shells, enabling long-term durability for encapsulated materials (enzymes and/or fungi) that provide penetration, self-healing, and corrosion prevention upon capsule rupture by an external source (i.e., crack opening, pH changes, aircraft passes on runways).
Image Caption: Schematic of Concrete Assisted by Particles Sealed Under Large-scale Encapsulation (CAPSULE)
Current stage of technology development: TRL 1
LLNL has filed for patent protection on this invention.
- long-term function for vascularizing effectors
- a novel delivery mechanism for deep vascularization
- minimal upkeep or renewal required
- versatile solution for both steel-reinforced and non-reinforced concrete
- novel portable non-destructive evaluation (NDE) to monitor performance
- tunable functionality according to the application space and the diagnostic needs
Concrete repair in airfields, civic infrastructure, military bases, oilfields
