TY - JOUR
T1 - Effect of the Ti-extracted residue on compressive strength and microstructural properties of modified cement mortar
AU - Sun, Keke
AU - Xuan, Dongxing
AU - Li, Jingjing
AU - Ji, Guangxiang
AU - Poon, Chi Sun
AU - Wang, Shuping
AU - Peng, Xiaoqin
AU - Lv, Xuewei
AU - Zeng, Guanwu
N1 - Funding Information:
This work was supported by the project of Natural Science Foundation of Chongqing (cstc2020jcyj-msxmX0954) and the Fundamental Research Funds for the Central Universities (2020CDJ-LHZZ-088). The Natural Science Foundation of China (51678093) and the Electron Microscope Centre of Chongqing University (202103150147) were also gratefully acknowledged. Thanks are given to the Pangang Group Research Institute Co., Ltd and the Project of Leading Talent of Science and Technology Innovation in Chongqing for financial support.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/2/21
Y1 - 2022/2/21
N2 - The Ti-extracted residue is a metallurgical solid waste and its utilization is limited in cement-based materials due to its high amount of chloride salts. In this study, the washed and unwashed Ti-extracted residues were used to replace high-quality supplementary cementitious materials, and the compressive strength and microstructural properties of the prepared specimens were studied. Incorporating the Ti-extracted residue in the cement paste can increase the early compressive strength due to the acceleration effect of the chloride salt on the hydration process, but the washed Ti-extracted residue reduced the later compressive strength due to its lower reactivity. Meanwhile, the Ti-extracted residue with its hydraulic and pozzolanic effects contributed to the formation of the C-S-H gel with a low Ca/Si ratio, which resulted in the consumption of calcium hydroxide and the lowering of the indentation modulus and hardness of the C-S-H gel. In addition, the leaching test demonstrated that the washed Ti-extracted residue was harmless to the environment, and the chlorine ion of the Ti-extracted residue can be physically and chemically bonded. Therefore, the washing method is an effective way to remove the soluble chlorine of the Ti-extracted residue and decrease its potential risk to environment. This research finding facilitated the recycling of the Ti-extracted residue as supplementary cementitious materials in cement-based materials.
AB - The Ti-extracted residue is a metallurgical solid waste and its utilization is limited in cement-based materials due to its high amount of chloride salts. In this study, the washed and unwashed Ti-extracted residues were used to replace high-quality supplementary cementitious materials, and the compressive strength and microstructural properties of the prepared specimens were studied. Incorporating the Ti-extracted residue in the cement paste can increase the early compressive strength due to the acceleration effect of the chloride salt on the hydration process, but the washed Ti-extracted residue reduced the later compressive strength due to its lower reactivity. Meanwhile, the Ti-extracted residue with its hydraulic and pozzolanic effects contributed to the formation of the C-S-H gel with a low Ca/Si ratio, which resulted in the consumption of calcium hydroxide and the lowering of the indentation modulus and hardness of the C-S-H gel. In addition, the leaching test demonstrated that the washed Ti-extracted residue was harmless to the environment, and the chlorine ion of the Ti-extracted residue can be physically and chemically bonded. Therefore, the washing method is an effective way to remove the soluble chlorine of the Ti-extracted residue and decrease its potential risk to environment. This research finding facilitated the recycling of the Ti-extracted residue as supplementary cementitious materials in cement-based materials.
KW - Hydration reaction
KW - Micromechanical property
KW - Supplementary cementitious materials
KW - Ti-extracted residue
KW - Waste management
UR - http://www.scopus.com/inward/record.url?scp=85121965811&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2021.126190
DO - 10.1016/j.conbuildmat.2021.126190
M3 - Journal article
AN - SCOPUS:85121965811
SN - 0950-0618
VL - 320
JO - Construction and Building Materials
JF - Construction and Building Materials
M1 - 126190
ER -