I'm following as a layperson, can you explain how to reach your takeaway from the bullets presented? It seems like #3 is almost identical to low-end normal concrete, so "good idea". Not sure what "24h" vs "2h" refers to though.
Difference is that compressive strength generally decreases over time. Here we have a product where it increases over time. Changes the equation on how you build and maintain it.
• Compressive strength of normal concrete: 25-50MPa
• Compressive strength of their slag concrete with 2h CO2 added: 12MPa
• Compressive strength of their slag concrete with 24h CO2 added: 24.3MPa
My takeaway:
Using slag instead of cement = good idea.
Using slag OR cement plus CO2 = bad idea.