TY - JOUR
T1 - Role of limestone powder in alkali-activated slag paste with superabsorbent polymer
AU - Liu, Xinyan
AU - Li, Bo
AU - Chen, Yung-Tsang
AU - Shi, Weizhuo
AU - Ghiassi, Bahman
N1 - The authors wish to acknowledge the financial support from Zhejiang Provincial Key R&D Programme (No.: 2023C03146), and Ningbo Municipal Bureau of Science and Technology under Commonweal Programme (No.: 2022S177), and Zhejiang Provincial Key Laboratory for Carbonaceous Wastes Processing and Process Intensification Research funded by the Zhejiang Provincial Department of Science and Technology (2020E10018)
PY - 2023/10/1
Y1 - 2023/10/1
N2 - Superabsorbent polymer (SAP) has been commonly used to mitigate the shrinkage of alkali-activated slag (AAS) pastes through internal curing. However, the effectiveness of internal curing might be affected by the microstructure of the pastes. Therefore, the effects of incorporating limestone powder (LP) on the microstructure and shrinkage of AAS pastes containing SAP are studied. The results reveal that incorporating LP mitigates the autogenous shrinkage of the pastes with SAP. This is because the incorporation of LP reduces the fraction of mesopores in the pastes containing SAP, while adding SAP maintains the internal relative humidity and increases the size of minimum pores that can drive autogenous shrinkage. In contrast, adding LP tends to enhance the driving force of autogenous shrinkage in the pastes without SAP due to the conversion of mesopores to gel pores. Furthermore, incorporating LP simultaneously enhances the reaction and generates more macropores in the pastes, causing a negligible influence on their mechanical properties and an increase of drying shrinkage. Overall, incorporating LP promotes the internal curing effectiveness in decreasing the autogenous shrinkage of the pastes.
AB - Superabsorbent polymer (SAP) has been commonly used to mitigate the shrinkage of alkali-activated slag (AAS) pastes through internal curing. However, the effectiveness of internal curing might be affected by the microstructure of the pastes. Therefore, the effects of incorporating limestone powder (LP) on the microstructure and shrinkage of AAS pastes containing SAP are studied. The results reveal that incorporating LP mitigates the autogenous shrinkage of the pastes with SAP. This is because the incorporation of LP reduces the fraction of mesopores in the pastes containing SAP, while adding SAP maintains the internal relative humidity and increases the size of minimum pores that can drive autogenous shrinkage. In contrast, adding LP tends to enhance the driving force of autogenous shrinkage in the pastes without SAP due to the conversion of mesopores to gel pores. Furthermore, incorporating LP simultaneously enhances the reaction and generates more macropores in the pastes, causing a negligible influence on their mechanical properties and an increase of drying shrinkage. Overall, incorporating LP promotes the internal curing effectiveness in decreasing the autogenous shrinkage of the pastes.
U2 - 10.1016/j.jobe.2023.107243
DO - 10.1016/j.jobe.2023.107243
M3 - Article
SN - 2352-7102
VL - 76
SP - 107243
JO - Journal of Building Engineering
JF - Journal of Building Engineering
ER -