TY - JOUR
T1 - Influence of Seawater on the Morphological Evolution and the Microchemistry of Hydration Products of Tricalcium Silicates (C3S)
AU - Yaseen, Sarah Abduljabbar
AU - Yiseen, Ghadah Abdaljabar
AU - Poon, Chi Sun
AU - Li, Zongjin
N1 - Funding Information:
This study was supported financially by the Hong Kong Research Grants Council Theme Based Research Scheme under the project Sustainable Marine Infrastructure Enabled by the Innovative Use of Seawater Sea-Sand Concrete and Fibre-Reinforced Polymer Composites, the grant number is T22-502/18-R. The authors would also like to acknowledge the assistance from the Materials Characterizations and Preparation Facilities (MCPF) at the Hong Kong University of Science and Technology. The authors acknowledge Zainab A. Yaseen for her help in proofreading the manuscript.
Publisher Copyright:
© 2020 American Chemical Society.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/10/26
Y1 - 2020/10/26
N2 - The current work investigates the influence of seawater on morphological properties during the hydration process of tricalcium silicate (C3S) at 3, 7, 14, and 28 days to better understand the effect of salinity (highly soluble salts) of seawater on the microstructural evolution of hydration products. The mechanism of the chemical reaction of highly soluble salts, e.g., Na2SO4 and CaCl2, with hydrated C3S was also demonstrated. The presence of highly soluble salts in seawater accelerates the hydration of C3S significantly due to releasing a significant amount of Ca2+ ions from the hydrated C3S (as CH and CSH), which participated in the chemical reaction to produce a certain amount of gypsum crystals that was more than that in distilled water, which has been shown by SEM characterization. TEM analysis revealed the growth of sharp rod-like CaSO4·2H2O crystals together with some thin and tiny wrinkled CSH that formed. Seawater promotes the hydration of C3S, pointed out by the expedited heat flow and raised heat of hydration. FTIR spectroscopy has been used to characterize and observe the dynamics of variation in the formation of calcium silicate hydrate (CSH), portlandite (CH), and gypsum (Gy) throughout the hydration process of C3S with seawater in comparison with distilled water. XRD analysis revealed that the peak intensities of the portlandite and gypsum of the hydrated C3S in seawater are higher than the comparable peaks in distilled water.
AB - The current work investigates the influence of seawater on morphological properties during the hydration process of tricalcium silicate (C3S) at 3, 7, 14, and 28 days to better understand the effect of salinity (highly soluble salts) of seawater on the microstructural evolution of hydration products. The mechanism of the chemical reaction of highly soluble salts, e.g., Na2SO4 and CaCl2, with hydrated C3S was also demonstrated. The presence of highly soluble salts in seawater accelerates the hydration of C3S significantly due to releasing a significant amount of Ca2+ ions from the hydrated C3S (as CH and CSH), which participated in the chemical reaction to produce a certain amount of gypsum crystals that was more than that in distilled water, which has been shown by SEM characterization. TEM analysis revealed the growth of sharp rod-like CaSO4·2H2O crystals together with some thin and tiny wrinkled CSH that formed. Seawater promotes the hydration of C3S, pointed out by the expedited heat flow and raised heat of hydration. FTIR spectroscopy has been used to characterize and observe the dynamics of variation in the formation of calcium silicate hydrate (CSH), portlandite (CH), and gypsum (Gy) throughout the hydration process of C3S with seawater in comparison with distilled water. XRD analysis revealed that the peak intensities of the portlandite and gypsum of the hydrated C3S in seawater are higher than the comparable peaks in distilled water.
KW - Calcium silicate hydrate (CSH)
KW - Gypsum
KW - Portlandite (CH)
KW - Salinity
KW - SEM
KW - TEM
KW - XRD
UR - http://www.scopus.com/inward/record.url?scp=85096084476&partnerID=8YFLogxK
U2 - 10.1021/acssuschemeng.0c04440
DO - 10.1021/acssuschemeng.0c04440
M3 - Journal article
AN - SCOPUS:85096084476
SN - 2168-0485
VL - 8
SP - 15875
EP - 15887
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
IS - 42
ER -
