2022 Volume 76 Issue 1 Pages 512-520
This study examined the effectiveness of accelerated carbonation using an externally heated rotary kiln for efficient CO2 uptake in recycled concrete aggregates. As a result, accelerated carbonation treatment was shown to be effective in promoting CO2 uptake of recycled concrete aggregates. Also, scale-up tests showed that operation at 500kg/h scale was stable, indicating the feasibility of process construction. Moreover, the amount of hexavalent chromium elution did not increase with accelerated carbonation, indicating that environmental safety is not a problem. It was confirmed that the modified CBR satisfied the quality standard for upper layer roadbed material and the high temperature （120℃） carbonated recycled concrete aggregates had sufficient performance as a roadbed material. These results indicate that recycled concrete aggregates treated by accelerated carbonation can be recycled as roadbed material.
