Scientists replaced 40 percent of cement with rice husk cinder, limestone crushing waste, and silica sand, giving concrete a rubber-like quality, six to nine times more crack-resistant than regular concrete. It self-seals, replaces cement with plentiful waste products, and should be cheaper to use.

[u/mvea]

https://newatlas.com/materials/rubbery-crack-resistant-cement/

[u/primaequa]

You are correct, but the amount released and captured during these stages is negligible relative the carbon emissions of turning raw minerals into clinker (and then Portland cement). If you're interested in details search Concrete LCAs or EPDs