Parallel Finite Element Model for Multispecies Transport in Nonsaturated Concrete Structures

Area of Science:

• Civil Engineering
• Materials Science
• Electrochemistry

Background:

• Chloride-induced corrosion of steel reinforcement is a major durability issue in reinforced concrete structures.
• Ionic species, including chloride ions, are transported into concrete from deicing salts.
• Accurate models are required to understand multispecies ionic transport mechanisms.

Purpose of the Study:

• To develop a robust mathematical model for coupled ionic transport mechanisms.
• To investigate the influence of ionic species interactions on transport.
• To implement a computational technique for solving complex ionic transport equations.

Main Methods:

• Developed a new mathematical model based on the Nernst-Planck equation and null current condition.
• Implemented the model using a parallel finite element algorithm.
• Verified the model against experimental data for ionic transport in saturated concrete.

Main Results:

• The model accurately predicted ionic transport in saturated concrete.
• Simulations in partially saturated concrete showed moisture movement and pressure gradients drive ionic species.
• The parallel finite element method proved effective for multispecies transport modeling.

Conclusions:

• The developed multispecies transport model is effective and accurate for concrete structures.
• The model can be used to solve partial differential equations governing ionic species transport.
• This research contributes to predicting and mitigating concrete degradation due to ionic ingress.