This has led to the development of self-healing concrete that can repair its own cracks, and scientists have now demonstrated an exciting new form of this that makes use of an enzyme found in human blood. Tiny cracks that form in concrete mightn't pose an immediate problem to the structural integrity of a construction, but as water gets in and the rupture spreads it can greatly compromise its strength. The idea with self-healing concrete is to intervene in this process while the cracks are still tiny, sealing up the material to prevent not just a catastrophic collapse, but expensive maintenance or a complete replacement of the structure.