Processes and systems for carbon dioxide sequestration and related concrete compositions

A process for the preparation of a carbonated concrete material, the process comprising the steps of:

• dissolving and/or blending carbon dioxide into water to produce a CO2-containing water comprising CO2 gas bubbles;
• mixing a concrete mixture with the CO2-containing water to produce a wet carbonated concrete mixture;
• and
• allowing the wet carbonated concrete mixture to harden and produce the carbonated concrete material upon hydration and carbonation thereof;
• wherein the concrete mixture comprises a cementitious material, aggregates and at least one CO2-sequestering chemical that releases species which are ready to be carbonated via the CO2-containing water, thereby increasing the captured amount of CO2 in the carbonated concrete material;
• and
• wherein the water is carried in a feed line at a water flow rate, and dissolving and/or blending carbon dioxide into the water comprises injecting the carbon dioxide into the feed line carrying the water and adjusting the water flow rate and a CO2 injection speed to deliver at least 1 kg of CO2 per m3 of wet concrete mixture.