Constitutive Modeling of Rheological Behavior of Cement Paste Based on Material Composition

Area of Science:

• Materials Science
• Civil Engineering
• Rheology

Background:

• Cementitious paste rheology is critical for fresh concrete properties like workability and uniformity.
• Existing rheological models fail to accurately capture complex cement-based system behaviors (flocculation, hydration) and rely on hard-to-measure parameters.
• This limits the practical application of rheological models in concrete technology.

Purpose of the Study:

• To develop a novel composition-based constitutive model for predicting cementitious paste rheology.
• To incorporate interparticle flocculation and entrapped water effects using a virtual maximum packing fraction (ϕmax).
• To establish quantitative links between powder characteristics and rheological parameters for practical predictions.

Main Methods:

• Introduced a virtual maximum packing fraction (ϕmax) into a constitutive model.
• Quantitatively correlated powder characteristics (particle size, specific surface area) with rheological parameters (yield stress, plastic viscosity).
• Validated the model against 65 diverse paste formulations, including plain and blended systems with varying admixtures and superplasticizer contents.

Main Results:

• Achieved high predictive accuracy: R² > 0.98 for plain pastes and R² > 0.85 for blended systems.
• Successfully captured the influence of superplasticizers by modifying ϕmax.
• Demonstrated the model's robustness and parameter efficiency.

Conclusions:

• The developed composition-based model accurately predicts cement paste rheology from fundamental material properties.
• This framework enables physically interpretable and measurable predictions, overcoming limitations of classical models.
• Offers a valuable tool for intelligent mix design in advanced concrete applications like self-consolidating and 3D-printed concrete.