Numerical Simulation of Non-Uniformly Distributed Corrosion in Reinforced Concrete Cross-Section

Area of Science:

• Civil Engineering
• Materials Science
• Corrosion Science

Background:

• Chloride corrosion of steel reinforcement is a primary cause of reinforced concrete structure degradation.
• Rust expansion around rebars leads to cracking and structural damage.
• Understanding the initiation phase of corrosion is crucial for predicting service life.

Purpose of the Study:

• To develop a numerical methodology for simulating the initiation phase of chloride-induced reinforcement corrosion.
• To estimate rust mass and define a corrosion level.
• To predict reinforcement depassivation time and analyze influencing factors.

Main Methods:

• Coupled numerical simulation of oxygen and chloride transport, and corrosion current flow.
• Analysis of a beam cross-section with four reinforcement bars.
• Parametric study on diffusion coefficients, chloride thresholds, and cover thickness.

Main Results:

• Prediction of evolving chloride concentration profiles around rebars.
• Estimation of time to reinforcement depassivation, varying with rebar position and surface location.
• Quantification of the influence of key parameters on corrosion initiation time.

Conclusions:

• The proposed numerical approach accurately simulates the chloride corrosion initiation phase.
• Reinforcement position and cover thickness significantly affect corrosion onset.
• The methodology provides a tool for assessing the durability of concrete structures exposed to chlorides.