Abstract

The air-void system of concrete is of paramount importance to ensure freeze–thaw durability. Pumping induces detrimental changes in the air-void system of concrete by dissolving the air bubbles in the surrounding water when pressure increases due to the pump action. This research work investigates the influence of shear rate and air-void size distribution on air dissolution with time of cement pastes under pressure. Steady-state shear rheology at different shear rates was applied on samples of different air-void size distributions but similar air contents. Due to the low capillary number of the mixtures, the application of pressure caused a decrease in viscosity. With increased applied shear rate and increased fineness of the air-void size distribution, the decrease in viscosity was more abrupt, indicating that the air dissolved almost immediately. Coarser air-void size distributions and lower shear rates caused a more gradual decrease in viscosity and thus a slower air dissolution. All experimental air dissolution times were lower than the calculated time needed for dissolution by pure diffusion. These results on the combined effect of pressure, duration, shear rate and air-void size distribution create the basis for a deeper understanding of the behavior of the air-void system of concrete during pumping.

Department(s)

Civil, Architectural and Environmental Engineering

Publication Status

Open Access

Comments

Bergens Forskningsstiftelse, Grant None

Keywords and Phrases

Air; Cement paste; Dissolution; Pressure; Rheology

International Standard Serial Number (ISSN)

1359-5997

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Springer, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Mar 2025

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