Ifsttar PhD subject

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Title : Control of the rheology of cement-based suspensions: reducing shear thickening

Main host Laboratory - Referent Advisor MAST - CPDM  -  BESSAIES-BEY Hela      tél. : +33 181668143

Director of the main host Laboratory ROUSSEL Nicolas  -

PhD Speciality Génie Civil et matériaux de construction

Axis of the performance contract 2 - COP2017 - More efficient and resilient infrastructure

Main location Marne-la-Vallée

Doctoral affiliation UNIVERSITE GUSTAVE EIFFEL

PhD school SCIENCES, INGENIERIE ET ENVIRONNEMENT (SIE)

Planned PhD supervisor ROUSSEL Nicolas  -  Université Gustave Eiffel  -  MAST - CPDM

Planned financing Contrat doctoral  - Université Gustave Eiffel

Abstract

Background and issues

The production of concrete, the most consumed material in the world, with low environmental impacts constitutes a major challenge for our current society. Partial substitution of clinker, the source of greenhouse gas emissions, by by-products from other industries (slag, silica fume, glass waste, agricultural waste, etc.) or by natural mineral resources (limestone, clay, bauxite, etc.) is one of the most promising avenues. This research area has been the subject of numerous scientific publications and a gradual evolution of standards [1,2]. However, questions relating to the effect of these materials on the rheology of concrete remain unanswered and limit the substitution rates and the type of addition [3].

These new-generation cement suspensions are characterized by their high solid volume fraction, which compensates for their low reactivity limited by mineral additions. These concentrated suspensions can exhibit high viscosities at high shear rates [4,5]. The resulting shear thickening behavior is often regarded as a major industrial problem, with considerable impact on processing, mixing, pumping or casting.
According to the literature [5], reducing the coefficient of friction of mineral particles by coating mineral surfaces with adsorbing polymers is one of the most relevant levers for reducing the shear thickening behavior of mineral suspensions. However, the mechanism of action of these adsorbing polymers and the role played by their molecular structure are not yet understood.

Thesis objectives

In this context, the aim of the thesis is to understand the mechanisms of action of polymers adsorbed on the surface of mineral particles and their consequences on the coefficient of friction and the shear thickening behavior of the suspension. The aim of this thesis is to subsequently develop levers for controlling the shear thickening of cement-based suspensions.
The approach proposed here is essentially experimental and analytical. It will be based on mineral suspensions (limestone, quartz), whose behavior well represents that of cementitious suspensions before setting. The use of these suspensions will enable us to easily vary ionic strength, solvent and ionic species. Once the physical phenomena behind macroscopic behavior have been understood and mastered, we will study cementitious suspensions.
The selected polymers aim to cover the range of molecules available when formulating a cementitious material, and to vary the conformation of adsorbed polymers and their affinity for the mineral surfaces. The effect of adsorbed polymers on the coefficient of friction between particles will be characterized by compressive rheology, with emphasis on packing properties under stress. The effect of polymers on shear thickening behavior will be characterized by standard shear rheometry. The most relevant parameters for reducing the coefficient of friction between particles and controlling shear thickening behavior will be identified.

Visibility and valorization

This thesis fits in perfectly with the scientific strategy of the Materials and Structures department of Gustave Eiffel University.
This work will be published in fundamental and applied journals. The presentation of this work at international conferences is also planned, and will help raise the profile of Gustave Eiffel University in the field of sustainable construction.

References

[1] M. C. G. Juenger, R. Siddique, Recent advances in understanding the role of supplementary cementitious materials in concrete, Cement and Concrete Research 78 (2015) 71–80.
[2] B. Lothenbach, K. Scrivener, R. D. Hooton, Supplementary cementitious materials, Cement and Concrete Research 41 (2011) 1244–1256.
[3] R. J. Flatt, N. Roussel, H. Bessaies-Bey, L. Caneda-Martínez, M. Palacios, F. Zunino, From physics to chemistry of fresh blended cements, Cement and Concrete Research, Volume 172, 2023, 107243, ISSN 0008 884
[4] F Toussaint, C Roy, and P-H Jézéquel. Reducing shear thickening of cement-based suspensions. Rheologica acta, 48(8):883–895, 2009.
[5] N. Fernandez, R. Mani, D. Rinaldi, D. Kadau, M. Mosquet, H. Lombois-Burger, J. Cayer-Barrioz, H. J. Herrmann, N. D. Spencer, and L. Isa , Microscopic Mechanism for Shear Thickening of Non-Brownian Suspensions ,Phys. Rev. Lett. 111, 108301 – Published 3 September 2013

Keywords : Cement, alternative binders, rheology, shear thickening

Main host Laboratory - Referent Advisor	MAST - CPDM - BESSAIES-BEY Hela tél. : +33 181668143
Director of the main host Laboratory	ROUSSEL Nicolas -
PhD Speciality	Génie Civil et matériaux de construction
Axis of the performance contract	2 - COP2017 - More efficient and resilient infrastructure
Main location	Marne-la-Vallée
Doctoral affiliation	UNIVERSITE GUSTAVE EIFFEL
PhD school	SCIENCES, INGENIERIE ET ENVIRONNEMENT (SIE)
Planned PhD supervisor	ROUSSEL Nicolas - Université Gustave Eiffel - MAST - CPDM
Planned financing	Contrat doctoral - Université Gustave Eiffel
Abstract Background and issues The production of concrete, the most consumed material in the world, with low environmental impacts constitutes a major challenge for our current society. Partial substitution of clinker, the source of greenhouse gas emissions, by by-products from other industries (slag, silica fume, glass waste, agricultural waste, etc.) or by natural mineral resources (limestone, clay, bauxite, etc.) is one of the most promising avenues. This research area has been the subject of numerous scientific publications and a gradual evolution of standards [1,2]. However, questions relating to the effect of these materials on the rheology of concrete remain unanswered and limit the substitution rates and the type of addition [3]. These new-generation cement suspensions are characterized by their high solid volume fraction, which compensates for their low reactivity limited by mineral additions. These concentrated suspensions can exhibit high viscosities at high shear rates [4,5]. The resulting shear thickening behavior is often regarded as a major industrial problem, with considerable impact on processing, mixing, pumping or casting. According to the literature [5], reducing the coefficient of friction of mineral particles by coating mineral surfaces with adsorbing polymers is one of the most relevant levers for reducing the shear thickening behavior of mineral suspensions. However, the mechanism of action of these adsorbing polymers and the role played by their molecular structure are not yet understood. Thesis objectives In this context, the aim of the thesis is to understand the mechanisms of action of polymers adsorbed on the surface of mineral particles and their consequences on the coefficient of friction and the shear thickening behavior of the suspension. The aim of this thesis is to subsequently develop levers for controlling the shear thickening of cement-based suspensions. The approach proposed here is essentially experimental and analytical. It will be based on mineral suspensions (limestone, quartz), whose behavior well represents that of cementitious suspensions before setting. The use of these suspensions will enable us to easily vary ionic strength, solvent and ionic species. Once the physical phenomena behind macroscopic behavior have been understood and mastered, we will study cementitious suspensions. The selected polymers aim to cover the range of molecules available when formulating a cementitious material, and to vary the conformation of adsorbed polymers and their affinity for the mineral surfaces. The effect of adsorbed polymers on the coefficient of friction between particles will be characterized by compressive rheology, with emphasis on packing properties under stress. The effect of polymers on shear thickening behavior will be characterized by standard shear rheometry. The most relevant parameters for reducing the coefficient of friction between particles and controlling shear thickening behavior will be identified. Visibility and valorization This thesis fits in perfectly with the scientific strategy of the Materials and Structures department of Gustave Eiffel University. This work will be published in fundamental and applied journals. The presentation of this work at international conferences is also planned, and will help raise the profile of Gustave Eiffel University in the field of sustainable construction. References [1] M. C. G. Juenger, R. Siddique, Recent advances in understanding the role of supplementary cementitious materials in concrete, Cement and Concrete Research 78 (2015) 71–80. [2] B. Lothenbach, K. Scrivener, R. D. Hooton, Supplementary cementitious materials, Cement and Concrete Research 41 (2011) 1244–1256. [3] R. J. Flatt, N. Roussel, H. Bessaies-Bey, L. Caneda-Martínez, M. Palacios, F. Zunino, From physics to chemistry of fresh blended cements, Cement and Concrete Research, Volume 172, 2023, 107243, ISSN 0008 884 [4] F Toussaint, C Roy, and P-H Jézéquel. Reducing shear thickening of cement-based suspensions. Rheologica acta, 48(8):883–895, 2009. [5] N. Fernandez, R. Mani, D. Rinaldi, D. Kadau, M. Mosquet, H. Lombois-Burger, J. Cayer-Barrioz, H. J. Herrmann, N. D. Spencer, and L. Isa , Microscopic Mechanism for Shear Thickening of Non-Brownian Suspensions ,Phys. Rev. Lett. 111, 108301 – Published 3 September 2013
Keywords :	Cement, alternative binders, rheology, shear thickening

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