Potential of CO2-Storage in Recycled Concrete Aggregates by Accelerated Carbonation

• To reduce the carbon footprint of cementitious materials and resource extraction intensity of concrete industry (natural gravel or crushed rock), usage of recycled concrete aggregate (RCA) in concrete and as a CO2-sink by accelerated carbonation is widely investigated. Implementation of this technology will not only reduce the climate impact, but also improve the performance of the RCA creating a truly circular material. At first, some locally available recycled concrete was crushed in different fractions and characterized. To quantify the adhered mortar/aggregate content ratio on the as-received RCA, an image analysis method (IAM) was introduced. The analysis revealed that the adhered mortar accounts for around 40% of the RCA independently on the fraction. The results of IAM of as-received RCA were used to evaluate its remaining potential of CO2-storage. The effect of accelerated carbonation on the quality of RCA was evaluated by means of water absorption. The carbonation was determined by means of thermogravimetric analyses (TGA) and its derivative curve (DTG) resulting in similar CO2-storage for coarse fractions 4/8 mm and 8/16 mm under the accelerated carbonation conditions.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Husbyggnad (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Building Technologies (hsv//eng)

Nyckelord

accelerated carbonation

IAM

Recycled concrete aggregate

TGA

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