The effect of sodium benzoate on the electrodeposition of zinc on carbon steel electrode from acidic chloride solution was studied by cyclic voltammetry (CV), differential capacitance (DC), chronoamperometry (CA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). A dimensionless graph model was used to analyze the nucleation process of zinc. It is found that the sodium benzoate has a blocking effect on the zinc electrodeposition when its concentration is higher than 0.03 M but will accelerate the formation rate of zinc nuclei when its concentration is lower than 0.03 M. Benzoate can be adsorbed on the surface of the electrode, which reduces the interface tension of electrode/solution and favors the formation and growth of zinc nuclei when its concentration is lower than 0.03 M, but forms a separated layer and retards the formation and growth of zinc nuclei when its concentration is higher than 0.03 M.

An experimental study was conducted to investigate the effects of stirrup corrosion, concrete strength, and the casting position on the behavior of bond between steel bars and concrete. Accelerated corrosion was applied to corrode the stirrups in concrete specimens under laboratory conditions. In total, 180 specimens were cast and tested in this experiment. The specimens have three nominal concrete strengths of C20, C40, and C50, two deformed steel bars of 18 mm in diameter set in a 200 × 200-mm diagonal concrete prism with two stirrups of 8 mm in diameter to provide confinement. The steel bars were cast with different pouring positions, namely the upper and lower ends. Five corrosion levels were investigated, namely 0%, 5%, 10%, 15%, and 20%, and 12 specimens were investigated for each corrosion level. A pull-out test was carried out to obtain the bond-slip curves. The test results indicate that the porosity of concrete has a great effect on bond degradation with the increase of the steel corrosion level.

Lithium silicate (LS) crack repairing material, working as a crystal waterproof material, could be used to strengthen concrete made from solid waste materials. This paper presents the results of water absorption and rapid freeze–thaw tests with concrete specimens coated with LS. Concrete specimens with different water–binder ratios and air content (0.35–1 and 0.55–4.5) were tested. The moisture uptake and water absorption coefficient were analyzed in the water absorption test. The water absorption coefficient of LS-coated specimens was lower than that of uncoated specimens, resulting in a lower total moisture content. The relative dynamic modulus of elasticity was calculated by the fundamental transverse frequency (Er) and ultrasonic velocity (Ev), respectively. Er and Ev exhibited similar attenuation characteristics, and the attenuation of LS-coated specimens was lower than that of uncoated specimens. A two-segment freeze–thaw damage model based on Er and Ev was employed to predict the service life of concrete. The relative errors of the service life results calculated by Er and Ev were within 10%. The two-segment freeze–thaw model could be used for the service life prediction of concrete structures. The present work provides new insight into using LS to improve the service life of concrete.