Details
| Original language | English |
|---|---|
| Pages (from-to) | 129-139 |
| Number of pages | 11 |
| Journal | Cement and concrete research |
| Volume | 108 |
| Early online date | 5 Apr 2018 |
| Publication status | Published - Jun 2018 |
Abstract
This study quantifies the changes in the rheological properties of fresh concrete while focusing on lubricating layer (LL) formation during pumping. Full-scale pumping experiments were carried out on ready-mix concrete accompanied by the state-of-the-art rheological tests. Pumping markedly increased the yield stress. It also led to an increase in the air content, which contributed to a decrease in viscosity of fresh concrete. The dynamic loading from pumping generates a pressure gradient in concrete over the pipe cross-section. The pressure gradient is assumed to facilitate the movement of lubricating material to the concrete-wall interface, completing the formation of LL. This postulate is based on experimental evidence obtained by a portable high-pressure filter press and the extracted filtrate. The amount of filtrate depends on the specific surface of the fines, on concrete bulk viscosity, and on chemical admixtures. Finally, an increase in concrete temperature was observed depending on the concrete's composition and the properties of the LL.
Keywords
- Filtrate, Fresh concrete, Lubricating layer, Pumping, Rheology, Specific surface, Temperature
ASJC Scopus subject areas
- Engineering(all)
- Building and Construction
- Materials Science(all)
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In: Cement and concrete research, Vol. 108, 06.2018, p. 129-139.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Changes in concrete properties during pumping and formation of lubricating material under pressure
AU - Secrieru, Egor
AU - Cotardo, Dario
AU - Mechtcherine, Viktor
AU - Lohaus, Ludger
AU - Schröfl, Christof
AU - Begemann, Christoph
N1 - © 2018 Elsevier Ltd. All rights reserved.
PY - 2018/6
Y1 - 2018/6
N2 - This study quantifies the changes in the rheological properties of fresh concrete while focusing on lubricating layer (LL) formation during pumping. Full-scale pumping experiments were carried out on ready-mix concrete accompanied by the state-of-the-art rheological tests. Pumping markedly increased the yield stress. It also led to an increase in the air content, which contributed to a decrease in viscosity of fresh concrete. The dynamic loading from pumping generates a pressure gradient in concrete over the pipe cross-section. The pressure gradient is assumed to facilitate the movement of lubricating material to the concrete-wall interface, completing the formation of LL. This postulate is based on experimental evidence obtained by a portable high-pressure filter press and the extracted filtrate. The amount of filtrate depends on the specific surface of the fines, on concrete bulk viscosity, and on chemical admixtures. Finally, an increase in concrete temperature was observed depending on the concrete's composition and the properties of the LL.
AB - This study quantifies the changes in the rheological properties of fresh concrete while focusing on lubricating layer (LL) formation during pumping. Full-scale pumping experiments were carried out on ready-mix concrete accompanied by the state-of-the-art rheological tests. Pumping markedly increased the yield stress. It also led to an increase in the air content, which contributed to a decrease in viscosity of fresh concrete. The dynamic loading from pumping generates a pressure gradient in concrete over the pipe cross-section. The pressure gradient is assumed to facilitate the movement of lubricating material to the concrete-wall interface, completing the formation of LL. This postulate is based on experimental evidence obtained by a portable high-pressure filter press and the extracted filtrate. The amount of filtrate depends on the specific surface of the fines, on concrete bulk viscosity, and on chemical admixtures. Finally, an increase in concrete temperature was observed depending on the concrete's composition and the properties of the LL.
KW - Filtrate
KW - Fresh concrete
KW - Lubricating layer
KW - Pumping
KW - Rheology
KW - Specific surface
KW - Temperature
UR - http://www.scopus.com/inward/record.url?scp=85044587171&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2018.03.018
DO - 10.1016/j.cemconres.2018.03.018
M3 - Article
AN - SCOPUS:85044587171
VL - 108
SP - 129
EP - 139
JO - Cement and concrete research
JF - Cement and concrete research
SN - 0008-8846
ER -