Fiber bridging, simply explained
1. One-sentence answer
Fiber bridging is the action of fibers holding the two faces of a crack together after the matrix cracks.
2. Intuitive explanation
Imagine a crack opening like a small gap. Fibers crossing the gap act like many tiny bridges. If they pull out gradually instead of breaking immediately, they can keep carrying load and allow more cracks to form elsewhere.
3. Technical explanation
Fiber bridging is described by the relationship between bridging stress and crack opening displacement. It depends on fiber strength, diameter, length, orientation, chemical bond, frictional bond, pullout behavior, and dispersion. A good bridging law supplies enough stress and energy to satisfy PSH criteria.
4. Why it matters
Fiber bridging is the key mechanism that turns a brittle cementitious matrix into a ductile composite. It also helps reduce permeability and support self-healing by slowing flow through cracks and providing surfaces for healing products.
5. Representative evidence
- Node:
02_concepts/fiber_bridging_law.md. - Pullout node:
05_experiments/single_fiber_pullout.md. - Lab evidence: Lee 2010, Choi 2020, Hwang 2025 in
07_visualization/by_lee_lab_publications_claim_evidence_matrix.csv.
6. Common misunderstanding
Stronger bonding is not always better. If the bond is too strong, fibers may rupture rather than pull out, reducing ductility and crack-opening tolerance.
7. Linked Atlas nodes
02_concepts/fiber_bridging_law.md02_concepts/interface_properties.md02_concepts/fiber_dispersion.md05_experiments/single_fiber_pullout.md