TY - JOUR
T1 - Characterizing the Effects of Al(OH)3 and Mg(OH)2 on Reaction Products and Drying Shrinkage Characteristics of Alkali-activated Slag
AU - Li, Jing
AU - Yin, Suhong
AU - Huang, Haoliang
AU - Hu, Jie
AU - Yi, Chaofan
AU - Chen, Zheng
AU - Ma, Yuwei
AU - Ye, Guang
PY - 2022
Y1 - 2022
N2 - This study is undertaken to explore the relationship between the reaction products and the drying shrinkage of alkali-activated slag (AAS) with the varying hydroxide dosage. AAS pastes were firstly produced with either Al(OH)3 or Mg(OH)2 to investigate the effects of hydroxide on the composition of reaction products and the drying shrinkage of AAS. Secondly, the main reaction products formed in AAS pastes, viz. C4AH13, M4AH10, C-S-H, C-A-S-H and C-M-S-H, were synthesized individually. Synthetic products were then taken to cast the respective paste sample to examine the performance against the drying exposure. The results show that adding Mg(OH)2 indeed improved the shrinkage resistance of AAS. This is primarily connected to the increased crystalline phases, namely the hydrotalcite-like phases and the unreacted Mg(OH)2. Whereas adding Al(OH)3 did not relieve the drying shrinkage of AAS as the interlayer spacing of C-A-S-H was enlarged, which in turn allowed for more shrinkage. Further, the investigation of individual synthetic products illustrates that their drying shrinkage scales satisfied the following order: C4AH13 < M4AH10 < C-M-S-H < C-S-H < C-A-S-H. Moreover, the shrinkage scale of C-S-H was found to evolve as the Ca/Si ratio decreased.
AB - This study is undertaken to explore the relationship between the reaction products and the drying shrinkage of alkali-activated slag (AAS) with the varying hydroxide dosage. AAS pastes were firstly produced with either Al(OH)3 or Mg(OH)2 to investigate the effects of hydroxide on the composition of reaction products and the drying shrinkage of AAS. Secondly, the main reaction products formed in AAS pastes, viz. C4AH13, M4AH10, C-S-H, C-A-S-H and C-M-S-H, were synthesized individually. Synthetic products were then taken to cast the respective paste sample to examine the performance against the drying exposure. The results show that adding Mg(OH)2 indeed improved the shrinkage resistance of AAS. This is primarily connected to the increased crystalline phases, namely the hydrotalcite-like phases and the unreacted Mg(OH)2. Whereas adding Al(OH)3 did not relieve the drying shrinkage of AAS as the interlayer spacing of C-A-S-H was enlarged, which in turn allowed for more shrinkage. Further, the investigation of individual synthetic products illustrates that their drying shrinkage scales satisfied the following order: C4AH13 < M4AH10 < C-M-S-H < C-S-H < C-A-S-H. Moreover, the shrinkage scale of C-S-H was found to evolve as the Ca/Si ratio decreased.
KW - Alkali-activated slag
KW - drying shrinkage
KW - Al(OH)3
KW - Mg(OH)2
KW - reaction products
UR - http://www.scopus.com/inward/record.url?scp=85134654260&partnerID=8YFLogxK
U2 - 10.1016/j.cscm.2022.e01309
DO - 10.1016/j.cscm.2022.e01309
M3 - Article
SN - 2214-5095
VL - 17
JO - Case Studies in Construction Materials
JF - Case Studies in Construction Materials
M1 - e01309
ER -