Synthesis and Properties of a Clean and Sustainable Deicing Additive for Asphalt Mixture

A clean and sustainable deicing additive was prepared via the adsorption of acetate anions (Ac(-)) by magnesium (Mg) and aluminum (Al) calcined layered double hydroxide (Mg/Al-CLDH). Fourier transform infrared spectroscopy spectrums proved that Ac(-) had intercalated into LDH structure. X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy images showed that the intercalation spacing and platelet thickness of Mg and Al layered double hydroxide containing Ac(-) anions (Mg/Al-Ac(-) LDH) had been enlarged due to substitution of divalent CO(3) (2-) anions by a larger quantity of monovalent Ac(–) anions. Differential scanning calorimetry tests testified that the insoluble Mg2/Al-Ac(-) LDH evidently decreased the freeze point (FP) of water to -10.68°C. X-ray photoelectron spectroscopy analyses confirmed that the Ac- were strongly confined by the metal layers of LDHs. FP test of asphalt mixtures confirmed that Mg/Al-Ac(-) LDHs reduced FP to -5.5°C. Immersion test results indicated that Mg/Al-Ac(-) LDH had a good deicing durability and Ac(-) did not released from asphalt mixture. Snow melting observation was conducted further testified that Mg/Al-Ac(-) LDH melted snow or ice sustainably.