<abstract xmlns="http://www.w3.org/1999/xhtml">

Pumping is the preferred placement method for concrete. The pumping process influences fresh properties of concrete. Competent producers handle these issues when composing the mix design. However, sudden changes in workability sometimes appear, both in the form of increased and decreased workability. Both changes might be handled on-site. However, even the situations that are sufficiently handled, cause delays and extra costs. Sometimes the final result’s quality is compromised, resulting in repairs and economic compensation claims. The extent and causes of incidents with sudden changes in workability are still to be investigated.
It is suggested that around 1 100 000 m3 or 30% of concrete experience sudden change in workability annually in Norway, and that 200 000 kg of chemical admixtures is used on-site. It appears that the most relevant cause is to find within variations in the fine aggregate. Increase in workability might also be caused by lack of compatibility between superplasticiser and binding materials in low-carbon concrete, enhanced by the extra mixing process caused by the pumping process.
To approach these questions, the Quality Assessment system of a medium-sized Norwegian concrete producer has been investigated. It comprises documentation of 1 500 000 m3 of concrete, over 10 years.
</abstract>

Pumping is the preferred placement method for concrete. The pumping process influences fresh properties of concrete. Competent producers handle these issues when composing the mix design. However, sudden changes in workability sometimes appear, both in the form of increased and decreased workability. Both changes might be handled on-site. However, even the situations that are sufficiently handled, cause delays and extra costs. Sometimes the final result’s quality is compromised, resulting in repairs and economic compensation claims. The extent and causes of incidents with sudden changes in workability are still to be investigated.
It is suggested that around 1 100 000 m3 or 30% of concrete experience sudden change in workability annually in Norway, and that 200 000 kg of chemical admixtures is used on-site. It appears that the most relevant cause is to find within variations in the fine aggregate. Increase in workability might also be caused by lack of compatibility between superplasticiser and binding materials in low-carbon concrete, enhanced by the extra mixing process caused by the pumping process.
To approach these questions, the Quality Assessment system of a medium-sized Norwegian concrete producer has been investigated. It comprises documentation of 1 500 000 m3 of concrete, over 10 years.

Sudden Changes in Workability during Concrete Pumping – An Industrial Approach

Technology manager, Ribe Betong AS and PhD Candidate, Department of Engineering Sciences, Faculty of Engineering and Science

Professor, Department of Engineering Sciences, Faculty of Engineering and Science

Nordic Concrete Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Pumping is the preferred placement method for concrete. The pumping process influences fresh properties of concrete. Competent producers handle these issues...

Sudden Changes in Workability during Concrete Pumping – An Industrial Approach

Publié en ligne: 06 janv. 2024

Pages: 11 - 31

Reçu: 04 avr. 2023

Accepté: 28 nov. 2023

DOI: https://doi.org/10.2478/ncr-2023-0014

Mots clés
Workability, pumping, production, placement

© 2023 Øystein Mortensvik et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Sudden Changes in Workability during Concrete Pumping – An Industrial Approach

Publié en ligne: 06 janv. 2024

Pages: 11 - 31

Reçu: 04 avr. 2023

Accepté: 28 nov. 2023

DOI: https://doi.org/10.2478/ncr-2023-0014

Mots clésWorkability, pumping, production, placement

© 2023 Øystein Mortensvik et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
Workability, pumping, production, placement