Tuesday, 15 October 2019
Grand Ballroom (The Hilton Atlanta)
The main deterioration factor ions cause corrosion and expansion of concrete with chloride, sulfate and carbonate ions. It is a major problem in field of construction resulting in a huge economic loss, also inducing serious safety disasters frequently. Layered double hydroxides (LDHs) has been successfully used for various purposes owing to its anion-exchange property. Among them, the calcium-based LDHs can improve immobilizing the migration of chloride, sulfate and carbonate ions in cement-based materials. In this study, we will focus on the description of the structural transformation of CaFe LDHs and anion exchange mechanism of immobilizing deterioration factors. The formation of expanded-CaFe LDHs occurred under the calcination conditions (400℃, 550℃ and 700℃, respectively). The characterizations of the expanded-CaFe-LDH after the adsorption was investigated using ion chromatography, x-ray fluorescence, fourier transform infrared spectroscopy, x-ray diffraction, field emission scanning electron microscopy and transmission electron microscope. The adsorption mechanism of ions by the CaFe LDHs related with structure property variation that happens during calcination process.
