TY - JOUR
T1 - Internal curing of alkali-activated slag-fly ash paste with superabsorbent polymers
AU - Li, Zhenming
AU - Zhang, Shizhe
AU - Liang, Xuhui
AU - Granja, José
AU - Azenha, Miguel
AU - Ye, Guang
PY - 2020
Y1 - 2020
N2 - This study investigates the influences of internal curing on reducing the autogenous shrinkage of alkali-activated slag/fly ash (AASF) paste. The influences of internal curing with superabsorbent polymers (SAPs) on the reactions and microstructure of AASF paste are investigated. It is found that the SAPs absorb liquid mainly before the initial setting time of the paste. Afterwards, the liquid is gradually released, keeping the internal relative humidity of the paste close to 100%. The internal curing with SAPs can significantly mitigate the autogenous shrinkage of AASF paste, especially after the acceleration period of the reaction. The mitigating effect of internal curing is due to the mitigated self-desiccation in the paste, rather than the formation of a denser microstructure or expansive crystals. The cracking potential of AASF under restrained condition is also greatly mitigated by internal curing. Despite the slight reductions in the elastic modulus and the compressive strength, great improvement is obverted in the flexural strength of the paste. This work confirms the effectiveness of internal curing of AASF with SAPs and further provides a promising way to reduce the autogenous shrinkage of AASF without compromising its mechanical properties.
AB - This study investigates the influences of internal curing on reducing the autogenous shrinkage of alkali-activated slag/fly ash (AASF) paste. The influences of internal curing with superabsorbent polymers (SAPs) on the reactions and microstructure of AASF paste are investigated. It is found that the SAPs absorb liquid mainly before the initial setting time of the paste. Afterwards, the liquid is gradually released, keeping the internal relative humidity of the paste close to 100%. The internal curing with SAPs can significantly mitigate the autogenous shrinkage of AASF paste, especially after the acceleration period of the reaction. The mitigating effect of internal curing is due to the mitigated self-desiccation in the paste, rather than the formation of a denser microstructure or expansive crystals. The cracking potential of AASF under restrained condition is also greatly mitigated by internal curing. Despite the slight reductions in the elastic modulus and the compressive strength, great improvement is obverted in the flexural strength of the paste. This work confirms the effectiveness of internal curing of AASF with SAPs and further provides a promising way to reduce the autogenous shrinkage of AASF without compromising its mechanical properties.
KW - Alkali-activated slag/fly ash
KW - Autogenous shrinkage
KW - Cracking
KW - Internal curing
KW - Mechanical properties
KW - Microstructure
UR - http://www.scopus.com/inward/record.url?scp=85090137740&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2020.120985
DO - 10.1016/j.conbuildmat.2020.120985
M3 - Article
SN - 0950-0618
VL - 263
SP - 1
EP - 12
JO - Construction and Building Materials
JF - Construction and Building Materials
M1 - 120985
ER -