TY - JOUR
T1 - Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste
AU - Yoon, Seyoon
AU - Moon, Juhyuk
AU - Bae, Sungchul
AU - Duan, Xiaonan
AU - Giannelis, Emmanuel P.
AU - Monteiro, Paulo M.
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-I1-004021, KUS-C1-018-02
Acknowledgements: This publication was based on work supported in part by Award No. KUS-I1-004021 and No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). We acknowledge Sasol Company for a sample of Pural MG 63 HT.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
PY - 2014/6
Y1 - 2014/6
N2 - 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 g -1 and 257 mg g-1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol-1 or 121 mg g-1), 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. © 2014 Published by Elsevier B.V. All rights reserved.
AB - 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 g -1 and 257 mg g-1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol-1 or 121 mg g-1), 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. © 2014 Published by Elsevier B.V. All rights reserved.
UR - http://hdl.handle.net/10754/597775
UR - https://linkinghub.elsevier.com/retrieve/pii/S0254058414001163
UR - http://www.scopus.com/inward/record.url?scp=84897912528&partnerID=8YFLogxK
U2 - 10.1016/j.matchemphys.2014.02.026
DO - 10.1016/j.matchemphys.2014.02.026
M3 - Article
SN - 0254-0584
VL - 145
SP - 376
EP - 386
JO - Materials Chemistry and Physics
JF - Materials Chemistry and Physics
IS - 3
ER -