Comparative Analysis of Concrete Cracking and Reinforcement Corrosion in Concrete and Ultra-High-Performance Concrete Short Columns after Accelerated Corrosion

In this study, nine concrete short columns and nine UHPC (ultra-high-performance concrete) short columns were produced, and an accelerated corrosion test method was used to compare and analyze the cracking phenomena and reinforcement corrosion after different durations of electrical current application. The analysis revealed that the corrosion rate of the UHPC specimens was approximately half of that of the concrete specimens, demonstrating excellent corrosion resistance. Although the corrosion rate of the UHPC specimen was lower, the length of the internal steel reinforcement decreased more significantly under prolonged electrification. For example, after 38 days of accelerated corrosion, the internal steel reinforcement in the ordinary concrete specimen measured 48 mm in length, while in the UHPC specimen, it measured only 43 mm. It was also found that the corrosion rates of both the concrete and UHPC specimens were significantly lower than the theoretical corrosion rate. This discrepancy is attributed to the fact that Faraday’s law, used to calculate the theoretical corrosion rate, does not fully account for factors such as the thickness of the protective layer and chloride ion concentration. The actual corrosion rate of the concrete specimens was generally only 70% of the theoretical value, while the UHPC specimens showed a corrosion rate which was only 40% of the theoretical value.