Rheological and flow characteristics of fresh concrete in the rotational rheometer

Abstract

The coaxial cylinder rheometer is widely used to measure the torque and rotational speed (T-N) of fresh concrete. T-N can be transformed into the corresponding rheological parameters via the solution of the ‘Couette inverse problem’. However, the solution of the ‘Couette inverse problem’ is a theoretical solution, which may produce errors due to the complex geometric shape of the coaxial cylindrical rheometer and the possible plug or secondary flow. The purpose of this study is to investigate the rheological and flow behaviors of fresh concrete in the rotational rheometer by coupling CFD (Computational Fluid Dynamics) simulations and experiments. The efficient high-fidelity 3-D CFD simulations of fresh concrete flowing in the ConTec Viscometer 5 are conducted using the Reynolds Average Navier–Stokes (RANS) model with the Multi-Reference Frame (MRF). Both Bingham and Herschel–Bulkley (H–B) models are adopted, and the numerical simulations are validated against by experiments, which enhanced the confidence that RANS simulation with MRF could supplement the experiments and elucidate the rheological and flow behaviors of fresh concrete with the whole-flow domain information.

Keywords:

• coaxial cylinder rheometer
• CFD
• flow behaviors
• Bingham
• Herschel–Bulkley

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

The authors would like to acknowledge the financial support from the National Natural Science Foundation of China (No. 51878104), the National Key Research & Development Program of China (2020YFD1100304), China Overseas Expertise Introduction Project for Discipline Innovation (B18062), China Postdoctoral Science Foundation (2018M831063), and the Key Support Program of China for foreign experts (zcsf2021008).