Worked example
A 0.80 mm microbial case at 21 days uses a bounded classroom model: closure = min(0.80, 1.00) × 21 / 21 = 0.80 mm. The remaining aperture is 0.00 mm.
The 3D specimen is unavailable. The measured model and explanations remain active below.
Can this crack close itself?
Commit to a prediction, choose a mechanism, and inspect whether a continuous water path still reaches the reinforcement.
HEALING MECHANISM
LOCK YOUR PREDICTION
PREDICTION REQUIRED
Choose before running the specimen. The result will explain the evidence boundary.
READY TO TEST
Set the crack and mechanism, then lock a prediction.
Measure first. Then choose the mechanism.
The transfer boundary
At 1.10 mm, the same 21-day model closes at most 1.00 mm. A 0.10 mm path remains, so the evidence cannot support “every crack heals.”
Narrow autogenous range
The source places autogenous healing under 0.3 mm. This lab treats that as an eligibility boundary, not a universal strength claim.
Water and rebar
An open depth path can carry water toward reinforcement. The scene shows exposure qualitatively and does not invent a corrosion rate.
What is not modeled
No strength-recovery percentage, service life, cost, capsule performance, or structural-design recommendation is claimed.