CO₂ Uptake over Service Period of Concrete Structures and Recycling Process of Concrete Rubbles

Abstract

Although carbonation is a fundamental phenomenon for concrete structures, the amount of CO₂ has not been quantified, which is absorbed in concrete structures and recycling concrete aggregates due to the phenomenon. In the present paper, we quantify uptake of CO₂ over using phase and recycling process of concrete. We conduct TG-DTA analysis for on-site specimens widely collected around the nation. The following results are obtained. 1) Concrete structure absorbs 15kg-CO₂/t through its using phase. On exposed concrete structures, CO₂ uptake rate is twice as fast as that on buried ones. 2) Recycling concrete aggregate absorbs 9kg-CO₂/t through recycling process consisting of demolition, crushing and temporary storage. The increment degree is primary governed by particle size of the recycling concrete aggregate.