Modeling Anomalous Moisture Transport in Cement-Based Materials with Kinetic Permeability

Area of Science:

• Civil Engineering
• Materials Science
• Transport Phenomena

Background:

• Durability of reinforced concrete is linked to moisture in cement-based materials.
• Conventional models fail to simulate anomalous moisture transport observed in these materials.
• Accurate moisture prediction models are crucial for material performance assessment.

Purpose of the Study:

• To develop a novel moisture transport model for cement-based materials.
• To incorporate time-dependent permeability into moisture transport simulations.
• To accurately capture anomalous moisture transport phenomena.

Main Methods:

• Permeability was modeled as a kinetic variable dependent on saturation and time.
• Time-dependence was formulated using decay/growth functions.
• Saturation-dependence was calculated using the van Genuchten-Mualem (VGM) model.
• The model was validated against experimental data for cement pastes.

Main Results:

• The proposed model demonstrated good agreement with experimental data for drying and wetting cement pastes.
• Numerical simulations showed the model's capability in capturing anomalous moisture transport.
• Comparison with fractional derivative models and Weibull function highlighted the proposed model's effectiveness and physical basis.

Conclusions:

• The developed model successfully simulates anomalous moisture transport in cement-based materials.
• The kinetic approach to permeability provides a physically meaningful representation of moisture dynamics.
• This model offers a more accurate tool for predicting the long-term performance of concrete structures.