Improved Chloride Ion Penetration Resistance of Geopolymer by Adding Calcined Layered Double Hydroxides
WANG Aiguo1, LYU Bangcheng1, DUAN Ping2,3, WU Yueyue2, LIU Kaiwei1
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
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.
1 Safehian M, Ramezanianpour A A. Assessment of service life mo-dels for determination of chloride penetration into silica fume concrete in the severe marine environmental condition [J]. Construction and Building Materials,2013,48:287. 2 Diamanti M V, Brenna A, Bolzoni F, et al. Effect of polymer modified cementitious coatings on water and chloride permeability in concrete[J]. Construction and Building Materials,2013,49:720. 3 Ismail I, Bernal S A, Provis J L, et al. Influence of fly ash on the water and chloride permeability of alkali-activated slag mortars and concretes [J]. Construction and Building Materials,2013,48:1187. 4 Li X, Li C, Zhang H. Relationship between the free and total chloride diffusivity in concrete [J]. Cement and Concrete Research,2002,32(2):323. 5 Yang C, Cho S. An electrochemical method for accelerated chloride migration test of diffusion coefficient in cement-based materials [J]. Materials Chemistry and Physics,2003,81(1):116. 6 Gruber K, Ramlochan T, Boddy A, et al. Increasing concrete durability with high reactivity metakaolin[J]. Cement & Concrete Composites,2001,23(6):479. 7 Bernal J, Fenaux M, Moragues A, et al. Study of chloride penetration on concretes exposed to high-mountain weather conditions with presence of deicing salts [J]. Construction and Building Materials,2016,127:971. 8 Cavani C, Trfiro E, Vaccari A. Hydrotalcite-type anionic clays: Preparation, properties and applications [J]. Catalysis Today,1991,11(2):173. 9 Khan I A, Ohare D. Intercalation chemistry of layered double hydroxides: Recent developments and applications [J]. Journal of Materials Chemistry,2002,12:3191. 10 Carlino S. The intercalation of carboxylic acids into layered double hydroxides: A critical evaluation and review of the different methods [J]. Solid State Ionics,1997,98:73. 11 Gardner E A, Yun S K, Kwon T, et al. Layered double hydroxides pillared by macroplyoxometalates [J]. Applied Clay Science,1998,13:479. 12 Raki L, Rancourt D G, Detellier C. Preparation, characterization, and Moessbauer spectroscopy of organic anion intercalated pyroaurite-like layered double hydroxides[J]. Chemistry of Materials,1995,7:221. 13 He P G, Wang M R, Fu S, et al. Effects of Si/Al ratio on the structure and properties of metakaolin based geopolymer [J]. Ceramics International,2016,42(13):14416. 14 Zhang Z H, Provis J L, Reid A, et al. Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete [J]. Cement & Concrete Composites,2015,62:97. 15 Zhang Z H, Provis J L, Reid A, et al. Geopolymer foam concrete: An emerging material for sustainable construction [J]. Construction and Building Materials,2014,56:113. 16 Shao N N, Liu Z, Xu Y Y, et al. Fabrication of hollow microspheres filled fly ash geopolymer composites with excellent strength and low density [J]. Materials Letters,2015,161:451. 17 Luo X, Xu J Y, Li W M, et al. Effect of alkali-activator types on the dynamic compressive deformation behavior of geopolymer concrete [J]. Materials Letters,2014,124:310. 18 Tennakoon C, Shayan A, Sanjayan J G, et al. Chloride ingress and steel corrosion in geopolymer concrete based on long term tests [J]. Materials & Design,2017,116:287.19 Badar M S, Kunal K P, Bernal S A, et al. Corrosion of steel bars induced by accelerated carbonation in low and high calcium fly ash geopolymer concretes [J]. Construction and Building Materials,2014,61:79. 20 Ren D M, Yan C J, Duan P, et al. Durability performances of wollastonite, tremolite and basalt fiber-reinforced metakaolin geopolymer composites under sulfate and chloride attack[J] Construction and Building Materials,2017,134:56. 21 Meyn M, Beneke K, Lagaly G. Anion-exchange reactions of layered double hydroxides [J]. Inorganic Chemistry,1990,29:5201. 22 Olanrewaju J, Newalkar B L, Mancino C, et al. Simplified synthesis of nitrate form of layered double hydroxide [J]. Materials Letters,2000,15(6):307. 23 Nakayama H, Wada N, Tsuhako M. Intercalation of amino acids and peptides into Mg-Al layered double hydroxide by reconstruction method [J]. International Journal of Pharmaceutics,2003,269(2):469. 24 Wang G A, Wang C C, Chen C Y. Preparation and characterization of layered double hydroxides-PMMA nanocomposites by solution polymerization [J]. Journal of Inorganic and Organometallic Polymers and Materials,2005,15(2):239.
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2018, Vol. 32 
