TY - JOUR
T1 - Degradation characteristics of Portland cement mortar incorporating supplementary cementitious materials under multi-ions attacks and drying-wetting cycles
AU - Cheng, Shukai
AU - Wu, Ziyang
AU - Wu, Qiaoyun
AU - Chen, Xuyong
AU - Shui, Zhonghe
AU - Lu, Jian Xin
N1 - Funding Information:
This study was supported by the National Natural Science Foundation Project of China (No. 51679179 ), the Key Research and Development Program of Hubei Science and Technology Department (No. 2020BAB071 ) and Science Foundation Research Project of Wuhan Institute of Technology (No. K2021031 ).
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/8/20
Y1 - 2022/8/20
N2 - The multiple corrosive ions in seawater cause more severe concrete corrosion in tidal and splash zones. To understand the mechanisms of harmful ions in seawater under the real field conditions, four different synthetic multi-ions solutions (NaCl, NaCl + MgCl2, NaCl + Na2SO4 and NaCl + MgCl2+Na2SO4) were prepared. This study investigated the effects of external multi-ions solutions and repeated drying-wetting cycles on the degradation mechanisms of Portland cement mortar/paste with and without supplementary cementitious materials (SCMs) by using different microstructural techniques. It was found that the multi-ions solutions of Cl− + SO42− and Cl− + Mg2++SO42− aggravated the deterioration of mortar samples compared to the solution with Cl− alone under drying-wetting cycles. The cracks and larger pores were induced due to the formation of secondary ettringite, and the enlarged size of microvoids in mortar obviously affected the damage evolution and resulted in an accelerated deterioration of mortar samples. In addition, the incorporation of ground blast furnace slag (GBFS) significantly improved the corrosion resistance of cement-based materials and showed more efficient than other pozzolanic materials. This may be due to that aluminum incorporation could bridge the defective silicate chains and increase the polymerization degree of silicate tetrahedra in the C–S–H gel. Moreover, the matrix incorporated GBFS could effectively reduce pore defects and volumes of connected pores and large pores, which enhanced the resistance to multi-ions attack. These results can be provided a theoretical basis on the improvement of concrete durability under severe marine environmental attacks.
AB - The multiple corrosive ions in seawater cause more severe concrete corrosion in tidal and splash zones. To understand the mechanisms of harmful ions in seawater under the real field conditions, four different synthetic multi-ions solutions (NaCl, NaCl + MgCl2, NaCl + Na2SO4 and NaCl + MgCl2+Na2SO4) were prepared. This study investigated the effects of external multi-ions solutions and repeated drying-wetting cycles on the degradation mechanisms of Portland cement mortar/paste with and without supplementary cementitious materials (SCMs) by using different microstructural techniques. It was found that the multi-ions solutions of Cl− + SO42− and Cl− + Mg2++SO42− aggravated the deterioration of mortar samples compared to the solution with Cl− alone under drying-wetting cycles. The cracks and larger pores were induced due to the formation of secondary ettringite, and the enlarged size of microvoids in mortar obviously affected the damage evolution and resulted in an accelerated deterioration of mortar samples. In addition, the incorporation of ground blast furnace slag (GBFS) significantly improved the corrosion resistance of cement-based materials and showed more efficient than other pozzolanic materials. This may be due to that aluminum incorporation could bridge the defective silicate chains and increase the polymerization degree of silicate tetrahedra in the C–S–H gel. Moreover, the matrix incorporated GBFS could effectively reduce pore defects and volumes of connected pores and large pores, which enhanced the resistance to multi-ions attack. These results can be provided a theoretical basis on the improvement of concrete durability under severe marine environmental attacks.
KW - Deterioration
KW - Drying-wetting cycles
KW - Multi-ions solutions
KW - Pore structure
KW - Supplementary cementitious materials (SCMs)
UR - http://www.scopus.com/inward/record.url?scp=85130950110&partnerID=8YFLogxK
U2 - 10.1016/j.jclepro.2022.132378
DO - 10.1016/j.jclepro.2022.132378
M3 - Journal article
AN - SCOPUS:85130950110
SN - 0959-6526
VL - 363
JO - Journal of Cleaner Production
JF - Journal of Cleaner Production
M1 - 132378
ER -