It doesn't bind CO2 from air during setting- that's the disconnect.
By converting the carbonate to oxide, the calcium in cement is free to bond with silicates (and to a lesser extent other compounds).
That CO2 released during manufacture is now looking for a new home, which could either be a plant, or a weathering deposit of limestone which could use the CO2 in the air to convert its own carbonate to stable bicarbonate.
By converting the carbonate to oxide, the calcium in cement is free to bond with silicates (and to a lesser extent other compounds).
That CO2 released during manufacture is now looking for a new home, which could either be a plant, or a weathering deposit of limestone which could use the CO2 in the air to convert its own carbonate to stable bicarbonate.