Firstly, this is for creating concrete on mars, where resources are very scarce and making regular concrete is not viable. Secondly, to survive martian conditions, we need to build bases, a lot of very sturdy, structurally sound bases. And lastly, before the potato based concrete, blood was genuinely the most viable solution, being an easily renewable resource. IIRC the martian concrete is now magnitudes better than regular concrete.
Firstly, this is for creating concrete on mars, where resources are very scarce and making regular concrete is not viable. Secondly, to survive martian conditions, we need to build bases, a lot of very sturdy, structurally sound bases. And lastly, before the potato based concrete, blood was genuinely the most viable solution, being an easily renewable resource. IIRC the martian concrete is now magnitudes better than regular concrete.