TY - JOUR
T1 - A comparison of liquid-solid and gas-solid accelerated carbonation for enhancement of recycled concrete aggregate
AU - Liu, Songhui
AU - Shen, Peiliang
AU - Xuan, Dongxing
AU - Li, Long
AU - Sojobi, Adebayo
AU - Zhan, Baojian
AU - Poon, Chi Sun
N1 - Funding Information:
This work was supported by the Research Grants Council GRF ( PolyU 152144/17E ), and The Hong Kong Polytechnic University .
Publisher Copyright:
© 2021 Elsevier Ltd
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/4
Y1 - 2021/4
N2 - To enhance the properties of recycled concrete aggregates (RCA), a liquid-solid carbonation process was developed and compared with the conventional gas-solid pressurized carbonation method. The performance of RCA and the recycled aggregate concrete (RAC) prepared with the carbonated RCA by the two aforementioned carbonation methods was evaluated. The carbonation products assemblage, microstructure and porosity evolution were first characterized. The results indicated that after subjecting to a 10-min liquid-solid carbonation process, a reduction of 12.2% in RCA water absorption and an increase of 2.6% in density were achieved, which were more efficient when compared to the 24-h gas-solid pressurized carbonation. More importantly, the compressive strength of RAC prepared with the 6-h liquid-solid carbonated RCA was significantly improved. In light of microstructural analysis, the enhanced performance of RAC was attributed to more additional mono-carbonate (Mc) and C–S–H gel formed at the interface between the liquid-solid carbonated RCA and the new cement pastes.
AB - To enhance the properties of recycled concrete aggregates (RCA), a liquid-solid carbonation process was developed and compared with the conventional gas-solid pressurized carbonation method. The performance of RCA and the recycled aggregate concrete (RAC) prepared with the carbonated RCA by the two aforementioned carbonation methods was evaluated. The carbonation products assemblage, microstructure and porosity evolution were first characterized. The results indicated that after subjecting to a 10-min liquid-solid carbonation process, a reduction of 12.2% in RCA water absorption and an increase of 2.6% in density were achieved, which were more efficient when compared to the 24-h gas-solid pressurized carbonation. More importantly, the compressive strength of RAC prepared with the 6-h liquid-solid carbonated RCA was significantly improved. In light of microstructural analysis, the enhanced performance of RAC was attributed to more additional mono-carbonate (Mc) and C–S–H gel formed at the interface between the liquid-solid carbonated RCA and the new cement pastes.
KW - Gas-solid pressurized carbonation
KW - Interface
KW - Liquid-solid carbonation
KW - Recycled aggregate concrete
KW - Recycled concrete aggregate
UR - http://www.scopus.com/inward/record.url?scp=85101400229&partnerID=8YFLogxK
U2 - 10.1016/j.cemconcomp.2021.103988
DO - 10.1016/j.cemconcomp.2021.103988
M3 - Journal article
AN - SCOPUS:85101400229
VL - 118
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
SN - 0958-9465
M1 - 103988
ER -