Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Cement grouting design: a nomogram for velocity, plug thickness and shear rate
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.ORCID iD: 0000-0003-1667-8919
Golder Associates, Sweden.
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

 In recent decades, there has been a substantial increase in knowledge of the propagation of cement grout inside rock fractures, assuming the Bingham model. Yield stress is used as an important design parameter in estimating grout penetration and maximum penetration length. Due to the thixotropic nature of cement grouts, the yield stress depends on the shear history and shear rate present during propagation. Although analytical solutions for velocity, plug thickness and shear rate are available for one-dimensional geometries, a different approach must be used for two-dimensional radial Bingham fluid flow. This is due to the non-linear pressure and velocity distribution leading to a change of the plug thickness along the radial distance. In this work, an analytical approach is provided for the determination of the velocity, plug thickness and shear rate for a two-dimensional (2D) radial Bingham flow between parallel disks. The results were compared with rectilinear flow in a one-dimensional (1D) circular pipe and rectangular channel. In addition, numerical calculations and experimental tests were used to validate the results. A non-dimensional nomogram was also developed in order to facilitate the design of the grouting time with respect to velocity, plug thickness and shear rate. The relevant design parameters can be obtained from the nomogram for the corresponding relative spread of the grout, and it can therefore be used as a simple design tool for cement grouting.

Keyword [en]
grouting, grouting design, cement grout, Bingham number, shear rate, plug flow, thixotropy, yield stress
National Category
Geotechnical Engineering
Research subject
Civil and Architectural Engineering
Identifiers
URN: urn:nbn:se:kth:diva-176887OAI: oai:DiVA.org:kth-176887DiVA: diva2:868712
Note

The authors wish to acknowledge the financial support from the Swedish Rock Engineering Research Foundation (BeFo) and the Swedish Construction Industry Development Fund (SBUF). The experimental test using the fracture replica was performed at the Division of Geo Engineering, Chalmers University of Technology and gratefully acknowledged. QS 2015

Available from: 2015-11-11 Created: 2015-11-11 Last updated: 2015-11-12Bibliographically approved
In thesis
1. Rheology of cement grout : Ultrasound based in-line measurement technique and grouting design parameters
Open this publication in new window or tab >>Rheology of cement grout : Ultrasound based in-line measurement technique and grouting design parameters
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Grouting is performed in order to decrease the permeability and increase the stiffness of the material, especially soil and rock. For tunnelling and underground constructions, permeation grouting is done where cement based materials are pumped inside drilled boreholes under a constant pressure, higher than the ground water pressure. The aim of permeation grouting is to reduce the water flow into tunnels and caverns and to limit the lowering of the surrounding groundwater table. Cement based materials are commonly used as grout due to their availability and lower costs. To obtain a proper water sealing and reduce the lowering of the ground water table, a desired spread of grout must be achieved and the rheology of the cement grout is the governing factor for estimating the required spread. Rheological properties of cement grout such as viscosity and yield stress are commonly measured off-line using laboratory instruments, and some simple tools are available to make field measurements. Although the rheological properties of the grout that is used play a fundamental role in design and execution, no method has yet been developed to measure these properties in-line in field work. In addition to the real time measurement, there is no standard method for determining the yield stress for grouting applications. Despite the common usage of Bingham model fitting to determine the yield stress, the range of shear rate is often not specified or is neglected.

 

In this work, an in-line rheometry method combining the Ultrasound Velocity Profiling (UVP) technique with Pressure Difference (PD) measurements, known as “UVP+PD”, was successfully tested for continuous in-line measurements of concentrated micro cement based grouts. A major obstacle of using the ultrasound based methodology was the transducers, which would be capable of emitting sufficient acoustic energy and can be used in field conditions. The transducer technology was developed in a parallel project and the Flow-Viz industrial rheometer was found to be capable of detail measurement of the velocity profiles of cement grout. The shape of the velocity profiles was visualized, and the change in the shape of the profiles with concentration and time was observed. The viscosity and yield stress of the grout were determined using rheological models, e.g. Bingham and Herschel-Bulkley. In addition, rheological properties were determined using the non-model approach (gradient method) and the tube viscometry concept and were compared with results obtained using the rheological models. The UVP+PD method was found to be capable of determining the rheological behavior of cement grout regardless of the rheological model.

The yield stress of cement grout was investigated using off-line rheometry techniques and UVP+PD in-line measurements. Tests were performed applying different shear histories and it was found that two ranges of yield stress indeed exist. Therefore, the design value of yield stress should be chosen with respect to the prevailing shear rate at the grout front for the required spread of grout. In addition, an appropriate shear rate range should be used when a Bingham fitting is done to determine the yield stress. In order to estimate the shear rate, plug thickness and velocity for one dimensional and two dimensional geometry, a non- dimensional nomogram was developed. The advantage of using the nomogram is that it does not depend on the applied pressure and the rheological properties of the grout and can therefore, be used as a simple design tool. Analytical approaches were used for the estimation and good agreements were found with numerical calculations and experimental results.

In conclusion, in this work, it was found that it is possible to continuously measure the velocity profiles and determine the change of the rheological properties of cement grout using the ultrasound based UVP+PD method under field conditions. The yield stress was also investigated and it was found that two range of yield stress exist depending on the prevailing shear rate of the grout, which should be used for designing the grouting time at different conditions. In order to decide the design value of yield stress for grouting applications, a non-dimensional nomogram was developed that can be used to estimate the plug thickness, shear rate and velocity of the grout. 

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. xvi, 73 p.
Series
TRITA-JOB PHD, ISSN 1650-9501 ; 1021
Keyword
grouting, grouting design, cement grout, Bingham number, shear rate, plug flow, thixotropy, yield stress, in-line rheology, UVP+PD, Flow-Viz, viscosity bifurcation, aging, off-line rheometry, pump characteristics
National Category
Geotechnical Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-176885 (URN)
Public defence
2015-11-18, F3, Lindstedtsvägen 26, KTH Royal Institute of Technology, Stockholm, 13:00 (English)
Opponent
Supervisors
Note

Funding for the project was provided by the Swedish Rock Engineering Research Foundation (BeFo), The Swedish Research Council (FORMAS) and The Development Fund of the Swedish Construction Industry (SBUF), who are gratefully acknowledged. QC 20151112

Available from: 2015-11-12 Created: 2015-11-11 Last updated: 2015-11-12Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Rahman, Mashuqur

Search in DiVA

By author/editor
Rahman, MashuqurHåkansson, Ulf
By organisation
Soil and Rock Mechanics
Geotechnical Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 113 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf