Method for enhancement of mechanical strength and CO2 storage in cementitious products

A method for curing cementitious articles, the method comprising:

• providing a cementitious article formed from a mixture of a cement binder, aggregate, and water, the cement binder comprising Ca3SiO5;
• placing the cementitious article in a curing chamber;
• maintaining a curing relative humidity between about 40% and about 80% within the curing chamber;
• maintaining a curing temperature between about 50° C. and about 80° C. within the curing chamber;
• curing the cementitious article by flowing a mixture of dry steam and CO2 into the curing chamber while maintaining the curing relative humidity and the curing temperature for a duration between about 4 hours and about 24 hours, wherein
• a concentration of CO2 in the mixture of dry steam and CO2 is between about 2.5% and about 20.0%, by volume,
• Ca(OH)2 is formed by at least one of the reactions
• 2Ca3SiO5(s)+7H2O(l)→3CaO.2SiO2.4H2O(s)+3Ca(OH)2(s), and
• 2Ca3SiO5(s)+7H2O(g)→3CaO.2SiO2.4H2O(s)+3Ca(OH)2(s),
• CO2 from the mixture of dry steam and CO2 reacts with the cementitious article to form CaCO3 in the cementitious article by at least one of the reactions
• 2Ca3SiO5(s)+3CO2(g)+4H2O(l)→3CaO.2SiO2.4H2O(s)+3CaCO3(s), and
• Ca(OH)2(s)+CO2(g)→CaCO3(s)+H2O(l), and
• the cured cementitious article comprises a CO2 uptake equal to or greater than 15%, by weight.