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| Improved Chloride Ion Penetration Resistance of Geopolymer by Adding Calcined Layered Double Hydroxides |
| WANG Aiguo1, LYU Bangcheng1, DUAN Ping2,3, WU Yueyue2, LIU Kaiwei1
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1 Anhui Key Laboratory of Advanced Building Materials, Anhui Jianzhu University, Hefei 230022;
2 Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074;
3 Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan 430074 |
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Abstract The present work developed a new approach to improve the chloride ion penetration resistance of geopolymer based on ion-exchange and structure regeneration of the calcined layered double hydroxides (LDHs). XRD and TEM analyses were used to characterize the changes in composition and structure of LDHs which experienced calcination and Cl- intercalation. A potentiometric titrant was employed to measure the concentration variation of chloride ions at different depths to the geopolymer specimen surface after immersion test in NaCl solution. The effect of calcined LDHs on the microstructures of geopolymer was investigated by SEM and MIP. The experimental results show that after reaction with saturated NaCl solution, the dispersed and layered structure is redisco-vered, which exhibits the structure regeneration of calcined LDHs by means of Cl- adsorption. The chloride ion concentration profile demonstrates the improved chloride ion penetration resistance which can be attributed to the addition of calcined LDHs, as 3% calcined LDHs reduces the chloride ion concentration by nearly 44%. Meanwhile, we also observed a denser microstructure in the calcined-LDHs-contained geopolymer specimen.
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Published: 06 July 2018
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| About author:: Aiguo Wang, Ph. D., Associate Professor E-mail: wag3134@126.com Ping Duan (Correspondence), Ph. D., Associate Professor E-mail: duanping@cug.edu.cn |
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2018, Vol. 32 
