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Nicolas Burlion - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Chemical Degradation on mechanical behavior of a petroleum cement paste
    Cement and Concrete Research, 2011
    Co-Authors: Ismael Yurtdas, Shouyi Xie, Jianfu Shao, Nicolas Burlion, Jérémie Saint-marc, Garnier André
    Abstract:

    Cement paste used in the Oil Industry is generally subjected to Chemical Degradation due to flow of acid fluids in various situations. The present study focuses on the evolution of thermo-hydro-mechanical (THM) behavior with Chemical Degradation of petroleum cement paste. Triaxial compression tests with different confining pressures (0, 3, 10 and 20 MPa) are carried out on a standard oil cement paste in sound state and completely degraded state by ammonium nitrate solution under a temperature of 90 °C. The results obtained show that the material in its initial state exhibits a small elastic phase and a strong capacity of compaction. The mechanical behavior depends on the load induced pore water pressure. Because of the increase in porosity caused by Chemical Degradation, the mechanical strength (cohesion and friction angle) and Young's modulus decrease. The dependence of mechanical strength and Young's modulus on confining pressure is smaller in the Chemically degraded cement paste than in the sound one. In fine, the mechanical behavior of the whole material becomes more ductile. As a result, such effects of Chemical Degradation should be taken into account when modeling such cement paste materials exposed to such Chemical Degradations.

  • Deformation and Permeability Evolution of Petroleum Cement Paste Subjected to Chemical Degradation Under Temperature
    Transport in Porous Media, 2011
    Co-Authors: Ismael Yurtdas, Shouyi Xie, Jianfu Shao, Nicolas Burlion, Jérémie Saint-marc, André Garnier
    Abstract:

    The variation of permeability of typical petroleum cement paste is investigated as functions of mechanical loading and Chemical Degradation under the temperature of 90A degrees C. In sound material, the permeability classically increases with deviatoric stress due to microcracks and volumetric dilatancy but decreases with confining pressure. Chemical leaching leads to significant increase of porosity of cement paste. However, the permeability of degraded material is lower than that of sound material during triaxial compression tests; this is due to compaction of pores under confining pressure. Further, the permeability variation in degraded cement is much more sensitive to confining pressure than that of sound material. During triaxial creep test, the permeability of degraded material decreases with time while that of sound material increases; this shows that the Chemically leached material has a higher potential of volumetric compaction which is a key mechanism of plastic deformation. Coupled Chemical Degradation and triaxial compression tests are also performed. Under low confining pressure (3 MPa), the permeability increases with propagation of leaching front, and there is formation of preferential flow paths in the axial direction. However, with high confining pressure (10 MPa), there is no increase of permeability during Chemical leaching and creation of successive degraded layers in the flow direction.

  • experimental study of mechanical behaviour of cement paste under compressive stress and Chemical Degradation
    Cement and Concrete Research, 2008
    Co-Authors: Jianfu Shao, Nicolas Burlion
    Abstract:

    This paper presents experimental investigations of mechanical behaviour of a pure cement paste subjected to compressive stresses and Chemical Degradation. Two series of laboratory tests have been performed: decoupled and coupled Chemical-mechanical tests. Hydrostatic and triaxial compression tests have first been realized respectively on sound and Chemically degraded samples. The obtained results allow the characterization of basic mechanical responses of the tested cement paste and the identification of Chemical Degradation effects on the mechanical behaviour. In the coupled tests, the samples are simultaneously subjected to deviatoric stresses and Chemical leaching by aggressive solution flow. Variations of deformation of cement paste samples are measured during Chemical Degradation process. The results obtained in these tests can be used for the validation of chemo-mechanical constitutive modelling.

Jianfu Shao - One of the best experts on this subject based on the ideXlab platform.

  • influences of Chemical Degradation on mechanical behaviour of a limestone
    International Journal of Rock Mechanics and Mining Sciences, 2011
    Co-Authors: Shouyi Xie, Jianfu Shao
    Abstract:

    This paper is devoted to the experimental investigation of Chemical Degradation effects on mechanical behaviour of a porous limestone. Hydrostatic and triaxial compression tests are first performed, respectively, on sound and Chemically degraded samples. It is found that the Chemical Degradation induces the diminution of pore collapse limit stress, elastic modulus and material cohesion. Coupled triaxial creep-Chemical Degradation tests are also performed. The Chemical Degradation enhances time-dependant deformation and can generate significant increase in permeability through the formation of wormholes networks.

  • Influence of Chemical Degradation on mechanical behavior of a petroleum cement paste
    Cement and Concrete Research, 2011
    Co-Authors: Ismael Yurtdas, Shouyi Xie, Jianfu Shao, Nicolas Burlion, Jérémie Saint-marc, Garnier André
    Abstract:

    Cement paste used in the Oil Industry is generally subjected to Chemical Degradation due to flow of acid fluids in various situations. The present study focuses on the evolution of thermo-hydro-mechanical (THM) behavior with Chemical Degradation of petroleum cement paste. Triaxial compression tests with different confining pressures (0, 3, 10 and 20 MPa) are carried out on a standard oil cement paste in sound state and completely degraded state by ammonium nitrate solution under a temperature of 90 °C. The results obtained show that the material in its initial state exhibits a small elastic phase and a strong capacity of compaction. The mechanical behavior depends on the load induced pore water pressure. Because of the increase in porosity caused by Chemical Degradation, the mechanical strength (cohesion and friction angle) and Young's modulus decrease. The dependence of mechanical strength and Young's modulus on confining pressure is smaller in the Chemically degraded cement paste than in the sound one. In fine, the mechanical behavior of the whole material becomes more ductile. As a result, such effects of Chemical Degradation should be taken into account when modeling such cement paste materials exposed to such Chemical Degradations.

  • Deformation and Permeability Evolution of Petroleum Cement Paste Subjected to Chemical Degradation Under Temperature
    Transport in Porous Media, 2011
    Co-Authors: Ismael Yurtdas, Shouyi Xie, Jianfu Shao, Nicolas Burlion, Jérémie Saint-marc, André Garnier
    Abstract:

    The variation of permeability of typical petroleum cement paste is investigated as functions of mechanical loading and Chemical Degradation under the temperature of 90A degrees C. In sound material, the permeability classically increases with deviatoric stress due to microcracks and volumetric dilatancy but decreases with confining pressure. Chemical leaching leads to significant increase of porosity of cement paste. However, the permeability of degraded material is lower than that of sound material during triaxial compression tests; this is due to compaction of pores under confining pressure. Further, the permeability variation in degraded cement is much more sensitive to confining pressure than that of sound material. During triaxial creep test, the permeability of degraded material decreases with time while that of sound material increases; this shows that the Chemically leached material has a higher potential of volumetric compaction which is a key mechanism of plastic deformation. Coupled Chemical Degradation and triaxial compression tests are also performed. Under low confining pressure (3 MPa), the permeability increases with propagation of leaching front, and there is formation of preferential flow paths in the axial direction. However, with high confining pressure (10 MPa), there is no increase of permeability during Chemical leaching and creation of successive degraded layers in the flow direction.

  • experimental study of mechanical behaviour of cement paste under compressive stress and Chemical Degradation
    Cement and Concrete Research, 2008
    Co-Authors: Jianfu Shao, Nicolas Burlion
    Abstract:

    This paper presents experimental investigations of mechanical behaviour of a pure cement paste subjected to compressive stresses and Chemical Degradation. Two series of laboratory tests have been performed: decoupled and coupled Chemical-mechanical tests. Hydrostatic and triaxial compression tests have first been realized respectively on sound and Chemically degraded samples. The obtained results allow the characterization of basic mechanical responses of the tested cement paste and the identification of Chemical Degradation effects on the mechanical behaviour. In the coupled tests, the samples are simultaneously subjected to deviatoric stresses and Chemical leaching by aggressive solution flow. Variations of deformation of cement paste samples are measured during Chemical Degradation process. The results obtained in these tests can be used for the validation of chemo-mechanical constitutive modelling.

Garnier André - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Chemical Degradation on mechanical behavior of a petroleum cement paste
    Cement and Concrete Research, 2011
    Co-Authors: Ismael Yurtdas, Shouyi Xie, Jianfu Shao, Nicolas Burlion, Jérémie Saint-marc, Garnier André
    Abstract:

    Cement paste used in the Oil Industry is generally subjected to Chemical Degradation due to flow of acid fluids in various situations. The present study focuses on the evolution of thermo-hydro-mechanical (THM) behavior with Chemical Degradation of petroleum cement paste. Triaxial compression tests with different confining pressures (0, 3, 10 and 20 MPa) are carried out on a standard oil cement paste in sound state and completely degraded state by ammonium nitrate solution under a temperature of 90 °C. The results obtained show that the material in its initial state exhibits a small elastic phase and a strong capacity of compaction. The mechanical behavior depends on the load induced pore water pressure. Because of the increase in porosity caused by Chemical Degradation, the mechanical strength (cohesion and friction angle) and Young's modulus decrease. The dependence of mechanical strength and Young's modulus on confining pressure is smaller in the Chemically degraded cement paste than in the sound one. In fine, the mechanical behavior of the whole material becomes more ductile. As a result, such effects of Chemical Degradation should be taken into account when modeling such cement paste materials exposed to such Chemical Degradations.

Ismael Yurtdas - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Chemical Degradation on mechanical behavior of a petroleum cement paste
    Cement and Concrete Research, 2011
    Co-Authors: Ismael Yurtdas, Shouyi Xie, Jianfu Shao, Nicolas Burlion, Jérémie Saint-marc, Garnier André
    Abstract:

    Cement paste used in the Oil Industry is generally subjected to Chemical Degradation due to flow of acid fluids in various situations. The present study focuses on the evolution of thermo-hydro-mechanical (THM) behavior with Chemical Degradation of petroleum cement paste. Triaxial compression tests with different confining pressures (0, 3, 10 and 20 MPa) are carried out on a standard oil cement paste in sound state and completely degraded state by ammonium nitrate solution under a temperature of 90 °C. The results obtained show that the material in its initial state exhibits a small elastic phase and a strong capacity of compaction. The mechanical behavior depends on the load induced pore water pressure. Because of the increase in porosity caused by Chemical Degradation, the mechanical strength (cohesion and friction angle) and Young's modulus decrease. The dependence of mechanical strength and Young's modulus on confining pressure is smaller in the Chemically degraded cement paste than in the sound one. In fine, the mechanical behavior of the whole material becomes more ductile. As a result, such effects of Chemical Degradation should be taken into account when modeling such cement paste materials exposed to such Chemical Degradations.

  • Deformation and Permeability Evolution of Petroleum Cement Paste Subjected to Chemical Degradation Under Temperature
    Transport in Porous Media, 2011
    Co-Authors: Ismael Yurtdas, Shouyi Xie, Jianfu Shao, Nicolas Burlion, Jérémie Saint-marc, André Garnier
    Abstract:

    The variation of permeability of typical petroleum cement paste is investigated as functions of mechanical loading and Chemical Degradation under the temperature of 90A degrees C. In sound material, the permeability classically increases with deviatoric stress due to microcracks and volumetric dilatancy but decreases with confining pressure. Chemical leaching leads to significant increase of porosity of cement paste. However, the permeability of degraded material is lower than that of sound material during triaxial compression tests; this is due to compaction of pores under confining pressure. Further, the permeability variation in degraded cement is much more sensitive to confining pressure than that of sound material. During triaxial creep test, the permeability of degraded material decreases with time while that of sound material increases; this shows that the Chemically leached material has a higher potential of volumetric compaction which is a key mechanism of plastic deformation. Coupled Chemical Degradation and triaxial compression tests are also performed. Under low confining pressure (3 MPa), the permeability increases with propagation of leaching front, and there is formation of preferential flow paths in the axial direction. However, with high confining pressure (10 MPa), there is no increase of permeability during Chemical leaching and creation of successive degraded layers in the flow direction.

P Liu - One of the best experts on this subject based on the ideXlab platform.

  • Battery Cycle Life Prediction with Coupled Chemical Degradation and Fatigue Mechanics
    Journal of the Electrochemical Society, 2012
    Co-Authors: R. Deshpande, Mark Verbrugge, Y.t. Cheng, Joseph Wang, P Liu
    Abstract:

    Coupled mechanical-Chemical Degradation of electrodes upon charging and discharging has been recognized as a major failure mechanism in lithium ion batteries. The instability of commonly employed electrolytes results in solid electrolyte interphase (SEI) formation. Although the SEI layer is necessary, as it passivates the electrode-electrolyte interface from further solvent decomposition, SEI formation consumes lithium and thus contributes to irreversible capacity loss. In this paper, we study irreversible capacity loss in a graphite-LiFePO4 cell. Our results support the mechanism of irreversible capacity loss due to the consumption of lithium in forming SEI. We attribute irreversible capacity loss to diffusion induced stresses (DISs) that cause pre-existing cracks on the electrode surfaces to grow gradually upon cycling, leading to the growth of SEI on the newly exposed electrode surfaces. Because lithium is consumed in forming the new SEI, irreversible capacity loss continues with cycling. Along with the SEI formation upon newly exposed (cracked) surfaces, the existing SEI thickness also grows with cycling, resulting in additional loss of lithium. In this study, we provide, a simple mathematical model, based on the Paris’ Law formulation of mechanical fatigue, in combination with Chemical Degradation to explain battery life. We compare the predicted capacity at different temperatures with the experimental data obtained from electroChemical measurements on graphite-LiFePO4 cells.