Sulfate Ions Immobilization of Calcined Layered Double Hydroxides in Hardened Cement Paste and Concrete

马军涛^1,2,3，WANG Daguang²，段平^4,3，SHI Yanke^1,2

1. MWR Center for Levee Safety and Disease Prevention Research, Yellow River Institute of Hydraulic Research2. International Joint Research Lab for Eco-building Materials and Engineering of Henan, North China University of Water Resources and Electric Power3. State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology4. Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences

摘 要：The sulfate ions immobilization behavior of calcined layered double hydroxides（CLDHs） in the hardened cement paste was investigated. The experimental results show that the sulfate ions in cement paste are immobilized by CLDHs to reconstruct the layered structure and aggregate around CLDHs. The immobilization amount of sulfate ions by CLDHs reaches 4.74×10^-3 mol/g, while the increasing amount indicates non-linear relation with the addition of CLDHs. The incorporation of CLDHs decreases the amount of ettringite formed to limit the expansion of cement paste, which decays the sulfate reaction to enhance the sulfate resistance of concrete.

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