Dive summary:

• It's not often that something as basic as concrete gets two innovations in the span of a week, but Dutch scientists have come up with a mix-in ingredient to patch small starter cracks, rivaling Korean researchers' announcement of a coating that shoots for the same goal.
• The researchers at the Delft University of Technology have devised an ingredient for concrete that impregnates the material with bacteria that love the high-pH environment of concrete and that precipitate calcite when water reaches them through the first cracks in the concrete, creating a patch.
• The Dutch researchers said their goal was to prevent cracks that could widen and allow water to reach and weaken steel reinforcing inside the concrete.

From the article:

Basement(s), tunnels, and transportation infrastructure are among the proposed wet environments that could benefit from the innovation, which may be commercialized in four to five years. ...