STEM与日常科技·英语30篇（5）

2 / 30

细菌如何建造更坚固的混凝土

Traditional concrete cracks easily under stress, letting water and rust damage steel reinforcements.
Scientists discovered certain soil bacteria, like Bacillus pasteurii, can produce limestone naturally.
When mixed into concrete with calcium lactate and oxygen, these microbes ‘breathe’ and mineralize.
Their metabolic activity forms tiny calcium carbonate crystals inside micro-cracks.
This self-healing process seals gaps up to 0.5 mm wide within three weeks.
The repaired concrete regains up to 90% of its original strength without human intervention.
Unlike polymer additives, bacterial healing works repeatedly as new cracks appear.
Field trials show bridges and tunnels using this bio-concrete last 20–30% longer.
It also cuts long-term maintenance costs and reduces CO₂ emissions from repairs.
Here, microbiology meets civil engineering in a quietly revolutionary way.