Two corrosion inhibitors commonly used in concrete were selected to evaluate their corrosion inhibition properties against steel corrosion in concrete simulation solutions, and several composite snowmelt agents with different composition ratios were designed by compounding these two corrosion inhibitors with sodium chloride. Electrochemical tests were performed using a Solartron Modulab XM workstation. The electrochemical experimental setup was a standard three-electrode system. A saturated calomel electrode (SCE) was used as the reference electrode (RE), a platinum sheet was used as the counter electrode (CE), and the working electrode (WE) was made of two steel materials. The electrochemical specimens were 10 mm × 10 mm × 5 mm in size, encapsulated using epoxy resin to give an exposed area of 1 cm2, polished to 2000# and rinsed and blow-dried with distilled water and anhydrous ethanol for use.
The open-circuit test (OCP) time was first set to 30 min, and the impedance spectrum test was performed after the open-circuit potential was stabilized. The perturbation potential was set to 10 mV, and the frequency range of impedance spectral test was 105 Hz-10-2 Hz, and the results were fitted by ZSimpWin software. The starting potential for the dynamic potential polarization curve test was -250 mV vs. OCP, and the scan rate was 0.1667 mV/s. The test was terminated when the pitting current density reached 1 mA/cm2. The test solution was a saturated Ca(OH)2 solution with the addition of 0.4 M NaCl as the concrete simulation solution (SCP), with a pH around 12.5, and the addition of sodium D-gluconate and sodium molybdate at concentrations of 2, 4, 6, 8, and 10 mM, respectively.
