The Slump Flow of Cementitious Pastes: Simulation vs. Experiments

Area of Science:

• Materials Science
• Civil Engineering
• Computational Mechanics

Background:

• Accurate simulation of cementitious paste properties is vital for construction.
• Computational Fluid Dynamics (CFD) offers potential but faces numerical uncertainties.
• Slump flow tests are key for evaluating cementitious paste behavior.

Purpose of the Study:

• To evaluate the accuracy of CFD simulations for cementitious paste slump flow tests.
• To determine the impact of numerical setup on simulation accuracy.
• To analyze transient, viscosity-dependent flows in different pastes.

Main Methods:

• CFD simulations were employed, using rheometric data and Herschel-Bulkley regression for input.
• Spatial and temporal convergence were assessed, alongside two regularization methods (Papanastasiou and bi-viscosity).
• Slice geometry was compared to full 3D models for computational efficiency.

Main Results:

• Temporal and spatial refinements significantly impacted results.
• Optimized simulation setups reduced computational errors to <4% compared to experiments.
• Papanastasiou regularization proved more accurate than the bi-viscosity model.
• Slice geometry yielded accurate results with lower computational cost.

Conclusions:

• Refined CFD models enhance understanding of transient flow in cementitious pastes.
• The study provides a benchmark for future transient flow analyses in concrete.
• Optimized CFD simulations improve accuracy and efficiency in cement and concrete flow analysis.