Research on Corrosion-Induced Cracking Damage Mechanism and Hysteretic Performance of Reinforced Concrete Structures

WU Chao; BI Yutian; TAO Jia

doi:10.19329/j.cnki.1673-2928.2025.06.014

Abstract：To investigate the damage mechanism and hysteretic performance of reinforced concrete structures during corrosion-induced cracking,specimens were fabricated with protective layer thicknesses of 18 mm,24 mm,and 30 mm,and longitudinal reinforcement diameters spanning 16-40 mm.Tests including corrosion potential,electrochemical impedance spectroscopy(EIS),corrosion cracking damage characterization,hysteretic performance,and corrosion-induced cracking mechanism analysis were carried out in a simulated sodium chloride salt spray environment.The results indicate that salt spray exposure damages the surface film of reinforcement in reinforced concrete.The corrosion potential gradually increases from an initial value of approximately-150 mV,with fluctuations of up to 100-200 mV at specific time points,triggering pitting corrosion.Rust products generated from this process induce internal rust expansion force,leading to cracking.Cracks propagate radially around the reinforcement,and crack width is inversely proportional to the protective layer thickness.Before the critical corrosion-induced cracking moment,the corrosion rates of specimens with 18 mm,24 mm,and 30 mm protective layers are about 1.1％,1.6％,and 1.4％,respectively.Thirty hours post-critical cracking,the corrosion rates rise to about 1.53％,1.11％,and 1.09％,respectively.This reveals that a thicker protective layer correlates with a higher corrosion rate pre-critical cracking;however,post-critical cracking,concrete cracks provide pathways for corrosive media,accelerating corrosion in all specimens.Nevertheless,specimens with thicker protective layers restrict corrosion progression due to smaller crack widths,significantly reducing the corrosion rate difference across different protective layer thicknesses.Under cyclic loading,as the longitudinal reinforcement diameter increases from 16 mm to 40 mm,the load initiating significant specimen displacement increases from about 5 kN to 15 kN,and the maximum bearing load rises from about 25 kN to 45 kN.Furthermore,the hysteretic performance of reinforced concrete structures exhibits strong plastic deformation,demonstrating superior seismic performance.Appropriately reducing the protective layer thickness can effectively alleviate corrosion-induced cracking and improve service safety.