Why crack width matters
1. One-sentence answer
Crack width matters because durability problems usually enter concrete through cracks.
2. Intuitive explanation
A few wide cracks act like open doors for water, chlorides, and aggressive ions. Many tiny cracks are much less harmful because each crack is narrow and easier to block, heal, or tolerate.
3. Technical explanation
ECC controls crack width through distributed multiple cracking and fiber bridging. Crack width affects permeability, chloride diffusion, corrosion risk, self-healing, and service-life performance. In the Atlas, crack-width control is the bridge between micromechanical design and infrastructure durability.
4. Why it matters
Without crack-width control, tensile ductility alone is not enough. A ductile material that forms large cracks may still have poor durability.
5. Representative evidence
- Node:
05_experiments/crack_width_distribution.md. - Self-healing evidence:
07_visualization/by_lee_lab_publications_claim_evidence_matrix.csv. - Teaching module:
08_teaching/lecture_modules/04_crack_width_durability_self_healing.md.
6. Common misunderstanding
A common mistake is to look only at maximum tensile strain. For ECC, crack width and crack spacing are just as important because they determine durability and healing reliability.
7. Linked Atlas nodes
05_experiments/crack_width_distribution.md04_material_systems/self_healing_ecc.md02_concepts/permeability.md02_concepts/transport_properties.md