TY - JOUR
T1 - Enhanced Sulfate Resistance
T2 - The Importance of Iron in Aluminate Hydrates
AU - Huang, Xiao
AU - Hu, Shuguang
AU - Wang, Fazhou
AU - Yang, Lu
AU - Rao, Meijuan
AU - Tao, Yong
N1 - Funding Information:
This work was supported by National Key Research and Development Program of China (No. 2016YFB0303501), National Natural Science Foundation of China (No. 51802238), and Hubei Technology Innovation Key Program (No. 2018AAA004).
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - Sulfate erosion is one of the main durability issue of ordinary Portland cement (OPC) while used in a sulfate-rich environment. Two aluminate phases in OPC, tricalcium aluminate (C 3 A) and tetracalcium aluminoferrite (C 4 AF), are primarily responsible for sulfate attack but with different sulfate resistant performance. This paper therefore focuses on the internal sulfate invasion to hydration products of these two aluminate minerals and attempts to explain the role of irons in hydrates. Chemical shrinkage coupled with X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectra (EDS) are employed to determine the overall development of internal sulfate erosion of these hydrates. The results suggested that the doped iron in hydrogarnet (C 3 (A,F)H 6 ) dramatically changes crystal growth and leads to large size of polyhedral particle to tiny cubic grain of C 3 AH 6 , which contributes superior performance to sulfate erosion. As to another hydrate monosulfate, the introduction of Fe in C 4 (A,F)SH 12 causes a slightly worse sulfate resistance to C 4 ASH 12 . The substitution of iron to aluminum in hydrogarnet is the radical reason for better sulfate resistance of C 4 AF to C 3 A. This study greatly enhances the understanding of sulfate resistance to OPC.
AB - Sulfate erosion is one of the main durability issue of ordinary Portland cement (OPC) while used in a sulfate-rich environment. Two aluminate phases in OPC, tricalcium aluminate (C 3 A) and tetracalcium aluminoferrite (C 4 AF), are primarily responsible for sulfate attack but with different sulfate resistant performance. This paper therefore focuses on the internal sulfate invasion to hydration products of these two aluminate minerals and attempts to explain the role of irons in hydrates. Chemical shrinkage coupled with X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectra (EDS) are employed to determine the overall development of internal sulfate erosion of these hydrates. The results suggested that the doped iron in hydrogarnet (C 3 (A,F)H 6 ) dramatically changes crystal growth and leads to large size of polyhedral particle to tiny cubic grain of C 3 AH 6 , which contributes superior performance to sulfate erosion. As to another hydrate monosulfate, the introduction of Fe in C 4 (A,F)SH 12 causes a slightly worse sulfate resistance to C 4 ASH 12 . The substitution of iron to aluminum in hydrogarnet is the radical reason for better sulfate resistance of C 4 AF to C 3 A. This study greatly enhances the understanding of sulfate resistance to OPC.
KW - Aluminate hydrates
KW - Iron-doped
KW - Sulfate erosion
KW - Tetracalcium aluminoferrite
KW - Tricalcium aluminate
UR - http://www.scopus.com/inward/record.url?scp=85063135419&partnerID=8YFLogxK
U2 - 10.1021/acssuschemeng.8b06097
DO - 10.1021/acssuschemeng.8b06097
M3 - Journal article
AN - SCOPUS:85063135419
SN - 2168-0485
VL - 7
SP - 6792
EP - 6801
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
IS - 7
ER -