As global warming is higher by CO2, most of countries have an effort to develop CO2 reducing technology like a CO2 sequestration and a CO2 curing method using cement based materials. In this study, CO2 uptake rate and compressive strength were investigated when CO2 curing method was applied in cement mortar. The CO2 uptake rate was ranged from 10.1% to 11.6% by mass measurement method and from 6.2% to 16.3% by TGA method. This means that mass measurement method by electronic scale is more accurate than TGA method to estimate CO2 uptake rate. The early compressive strength of 1 hour CO2 curing specimens was higher than that of 1 hour atmospheric curing specimens, but lower than that of 5 hours steam curing specimens. 3 days and 7 days compressive strength of specimens by atmospheric curing and steam curing were increased both. But compressive strength of 1 hour CO2 curing specimens was lower than that of other two curing methods.

Carbon dioxide generated from construction materials and construction material industry among the fields ofconstruction is approximately 67 million tons. It is about 30% of the carbon dioxide generated in the fields of construction.In order to reduce carbon dioxide in the fields of construction, it is necessary to control the use of fossil fuel consumedand decrease carbon emission by reducing the secondary and tertiary curing generating carbon dioxide in constructionmaterial industry. Therefore, this study manufactured mortar by having cement as the base and substituting three bindingmaterials up to 50% and then adopted different curing methods to analyze congelation and strength characteristics. According to the result of strength characteristics by the types of binding materials and replacement ratio, the specimensubstituting ESA (Early Strength Admixture) and FPC (Fine Particle Cement) showed active strength improvement. Inparticular, the specimen substituting ESA as 25% indicated the greatest strength improvement, and as the number of curingincreased, the strength grew higher, too. And when the binding material was used by substitution, it showed strengthcharacteristics similar to or higher than the specimen conducting tertiary autoclave curing as the secondary steam curing.