Estimation of Lubrication Layer Thickness and Composition through Reverse Engineering of Interface Rheometry Tests

During concrete pumping, a lubrication layer is formed near the pipe wall. Extensive research has been performed on measuring and modeling the properties of this layer and using these values to predict pumping pressures. However, there are numerous discussions in the literature about the composition...

Full description

Saved in:
Bibliographic Details
Published in:Materials 2020-04, Vol.13 (8), p.1799
Main Authors: Salinas, Alexis, Feys, Dimitri
Format: Article
Language:English
Subjects:
Aggregates
Cement
Cement paste
Composition
Concrete
Grain size
Hydration
Lubrication
Mortars (material)
Particle size
Pumping
Reverse engineering
Rheological properties
Rheology
Rheometers
Rheometry
Shearing
Thickness
Velocity
Viscosity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:During concrete pumping, a lubrication layer is formed near the pipe wall. Extensive research has been performed on measuring and modeling the properties of this layer and using these values to predict pumping pressures. However, there are numerous discussions in the literature about the composition and thickness of this layer: can it be considered mortar, a micromortar, or is it cement paste? In this paper, possible solutions for the thickness and composition of the lubrication layer are derived from interface rheometry tests. It is assumed that the lubrication layer is composed of one or more concentric layers of paste or micromortar. To accomplish this determination, the rheological properties of the composing paste, mortars with different maximum particle sizes and concrete need to be known. Challenges arising from using different rheometers and from the sensitivity of the paste rheology to shearing are addressed in this contribution. The results show that, mathematically, a single layer of homogeneous paste or mortar with different maximum particle sizes can be responsible for the formation of the lubrication layer. Physically, however, the composing material should contain sand particles to some extent, as particle migration is proportional to the size squared. If the literature results from pumping are applicable to the results obtained in this paper, it seems that the lubrication layer is composed of a mortar with a maximum particle size of around 1 to 2 mm.
ISSN:1996-1944
1996-1944
DOI:10.3390/MA13081799