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Engineering

Why Concrete Cracks and How to Make It Heal Itself

Quick fact

Certain self-healing concrete mixes embed dormant bacteria that, when water seeps into a crack, germinate and produce limestone, filling the crack in a few weeks.

Why this is interesting

You might think concrete is indestructible—but have you ever wondered why the sidewalk outside your house is covered in hairline cracks, and what if those cracks could repair themselves?