Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1522020 | Materials Chemistry and Physics | 2014 | 11 Pages |
Abstract
This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg gâ1 and 257 mg gâ1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol molâ1 or 121 mg gâ1), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Seyoon Yoon, Juhyuk Moon, Sungchul Bae, Xiaonan Duan, Emmanuel P. Giannelis, Paulo M. Monteiro,