Carbonation of cement mixes

A method of carbonating concrete comprising

• i) pumping a wet concrete mix into a conduit at a pressure sufficient to move the concrete through the conduit at a desired rate;
• ii) introducing carbon dioxide into the conduit at a pressure at or above the pressure of i);
• wherein the carbon dioxide is transported to the conduit in liquid form and released into the conduit under conditions whereby the carbon dioxide becomes gaseous and solid in the conduit.