Éric Samson - Academia.edu (original) (raw)
Papers by Éric Samson
The paper reviews approaches that have been used to model the degradation of cementitious materia... more The paper reviews approaches that have been used to model the degradation of cementitious materials exposed to aggressive aqueous environments such as pure water, acid solutions, sulfate-bearing solutions and other exposure conditions that alter the hydrated paste microstructure. The review showed that multiionic approaches are being used frequently to predict the microstructure alteration in those conditions. Some models also couple ionic transport predictions with mechanical analysis to predict the volume modifications of structures exposed to these aggressive environments.
A sensitivity analysis of the parameters involved in a multiionic reactive transport model that c... more A sensitivity analysis of the parameters involved in a multiionic reactive transport model that can be used, among other applications, to predict chloride ingress in concrete structures is presented. The analysis is based on the calculation of the elasticity of each parameter using a rigorous mathematical method. It was performed for two different test cases. The first concerns the penetration of chloride ions in saturated concrete during a simple ponding experiment while the second one involves the influence of wetting and drying cycles on chloride ingress. The analysis indicates that porosity and tortuosity (i.e. ionic diffusion coefficients) are the material parameters which have the most important impact on the model predictions. Boundary conditions were also found to have a significant influence on the output of the model. On the other hand, simulations were found to be much less affected by parameters such as the initial pore solution chemistry and the initial solid phase cont...
Materials and Structures, 2014
The Rosenblueth point estimator method is used to propagate uncertainty on stochastic parameters ... more The Rosenblueth point estimator method is used to propagate uncertainty on stochastic parameters in a multi-ionic reactive transport model for concrete degradation. The degradation mechanism that was analysed is the ingress of chlorides into concrete. This point estimator method is used because it requires a minimum number of simulations to compute means, standard deviations and skewness for the solution of the transport model. Two exposure cases are considered in this article: the first is a saturated case, and the second is an unsaturated case with wetting (4 days) and drying (3 days at 50 % relative humidity) cycles. The sodium chloride exposure during the wetting cycle of both cases was 500 mmol/L. In both cases, predictions from the model were compared to experimental results. The Rosenblueth approach yielded results comparable to Monte Carlo simulations for both saturated and unsaturated cases. The relative sensitivity of model parameters on prediction results are investigated through a sensitivity analysis. The sensitivity results show the high importance of ionic diffusion parameters and of exposure conditions, while the calculated initial mineral phases in the hydrated paste have lower importance.
Materials and Structures, 2013
Results of a statistical analysis of transport properties measurements carried out on a number of... more Results of a statistical analysis of transport properties measurements carried out on a number of concrete mixtures are presented. Migration and drying experiments were performed to evaluate the ionic diffusion coefficients and permeability of concrete mixtures. Seven concrete mixtures were tested. The mixtures were either batched under laboratory conditions or sampled from construction sites. For each mixture, approximately eighty concrete samples from a single batch were tested. Ionic diffusion coefficients were calculated by analyzing the evolution of the electrical current passing through concrete samples during the migration tests. Calculations took into account the volume of permeable pores of the materials and the pore solution chemistry. Permeability was calculated from mass loss measured during drying tests. The study indicates that the coefficient of variation of ionic diffusion coefficients is 11.1 % on average, with a maximum of 23.5%, and that the coefficient of variation of permeability is 20.6% on average, with a maximum of 37.3%. Keywords Concrete • Variability •Transport properties • Service life Accordingly, the construction industry started to develop new approaches to increase the service-life of concrete structures. Traditional prescriptive methods, still very much in use today, are in many cases replaced or combined with performance and design specification. In this approach, criteria for durability, such as a targeted service-life duration, are specified. This type of approach was progressively added to construction codes. For example, language for performance specification was incorporated in Canadian standard CSA A23.1-04 1 [9], and defined as a method for specifying a construction product in which the final outcome is given in mandatory language, in a manner that the performance requirements can be measured by accepted industry standards and methods. The Unified Facilities Guide Specification (UFGS), issued by U.S federal agencies in 2010, is another construction guide that incorporates performance-based language for new concrete construction [17]. This new trend in construction methods prompted in recent years the development of numerical tools to support asset management and decision-making to optimize design, service-life, and maintenance of new and existing structures. Reactive transport models dedicated to the prediction of chloride ingress and other deleterious species in reinforced structures became a central element of this new emphasis on long-term service-life predictions [8, 25].
Cement and Concrete Research, 2005
A description of ionic transport in unsaturated porous materials due to gradients in the electro-... more A description of ionic transport in unsaturated porous materials due to gradients in the electro-chemical potential and the moisture content is developed by averaging the relevant microscopic transport equations over a representative volume element. The complete set of equations consists of time-dependent equations for both the concentration of ionic species within the pore solution and the moisture content within the pore space. The electrostatic interactions are assumed to occur instantaneously, and the resulting electrical potential satisfies Poisson's equation. Using the homogenization technique, moisture transport due to both the liquid and vapor phases is shown to obey Richards' equation, and a precise definition of the moisture content is found. The final transport equations contain transport coefficients that can be unambiguously related to experimental quantities. The approach has the advantage of making the distinction between microscopic and bulk quantities explicit.
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... Bentz01influenceof, author = {Dale P. Bentz and Eric Samson and Yannick Maltais and Jacques M... more ... Bentz01influenceof, author = {Dale P. Bentz and Eric Samson and Yannick Maltais and Jacques March and Jacques March and Dale Bentz and Eric Samsonl and Yannick ... 1, Modelling calcium leaching mechanisms in hydrated cement pastes Delagrave, GerardI, et al. - 1997. ...
ABSTRACT Calcium hydroxide is one of the main,reaction products resulting from,the hydration of P... more ABSTRACT Calcium hydroxide is one of the main,reaction products resulting from,the hydration of Portland cement,with water. It is also one of the more,soluble phases found,in hydrated cement,systems. The influence of calcium hydroxide dissolution and,its effect on the diffusion properties of hydrated cement pastes were investigated using the NIST CEMHYD3D cement,hydration and,microstructure development,model. The results of these simulations were implemented,in another numerical model,called STADIUM. This latter model,can be used to predict the transport of ions in unsaturated porous
RILEM State-of-the-Art Reports, 2012
Materials and Structures, 2006
As part of the U.S. Navy program for the Modular Hybrid Pier development, a predictive durability... more As part of the U.S. Navy program for the Modular Hybrid Pier development, a predictive durability analysis has been carried out to establish the feasibility of using lightweight aggregate concrete mixtures to achieve the 100-year design life under severe marine conditions. The long-term durability of concrete was predicted using both laboratory testing and numerical modeling.
Materials and Structures, 2003
... 158 Page 4. Samson, Marchand, Snyder ... 4.2 Non steady-state migration experiments In an att... more ... 158 Page 4. Samson, Marchand, Snyder ... 4.2 Non steady-state migration experiments In an attempt to determine chloride diffusion coefficient, Tang and Nilsson [38] proposed an analysis of migration test results based on non steady-state measurements. ...
Journal of ASTM International, 2008
Journal of Colloid and Interface Science, 1999
The main features of a numerical model aiming at predicting the drift of ions in an electrolytic ... more The main features of a numerical model aiming at predicting the drift of ions in an electrolytic solution upon a chemical potential gradient are presented. The mechanisms of ionic diffusion are described by solving the extended Nernst-Planck system of equations. The electrical coupling between the various ionic fluxes is accounted for by the Poisson equation. Furthermore, chemical activity effects are considered in the model. The whole system of nonlinear equations is solved using the finite-element method. Results yielded by the model for simple test cases are compared to those obtained using an analytical solution. Applications of the model to more complex problems are also presented and discussed.
International Journal for Numerical Methods in Engineering, 1999
The main features of a numerical model aiming at predicting the drift of ions in electrolytic sol... more The main features of a numerical model aiming at predicting the drift of ions in electrolytic solutions are presented. The mechanisms of ionic diffusion are described by solving the Nernst–Planck system of equations. The electrical coupling between the various ionic fluxes is accounted for by the Poisson equation. Two algorithms using the finite element method for spatial discretization are compared for simple test cases. One is based on the Picard iteration method while the other is based on the Newton–Raphson scheme. Test results clearly indicate that the range of application is broader for the algorithm based on the Newton–Raphson method. Selected examples of the application of the algorithm to more complex 1-D and 2-D cases are given. Copyright © 1999 John Wiley & Sons, Ltd.
Computers & Structures, 2007
This paper gives the details of the multiionic transport model STADIUM® intended to describe the ... more This paper gives the details of the multiionic transport model STADIUM® intended to describe the degradation of cement-based materials exposed to aggressive environments. The main algorithm is based on an operator splitting approach. The first part of the calculations is dedicated to solving the transport equations without considering the chemical reactions. The concentration profile of each ionic species is calculated
Cement and Concrete Research, 2004
Portland cement systems are often exposed to severe environments, and their long-term performance... more Portland cement systems are often exposed to severe environments, and their long-term performance is of concern. The main results of a comprehensive investigation of deterioration processes that may affect the behavior of Portland cement systems exposed to chemically aggressive environments is presented. As part of this investigation, well-cured cement paste discs were fully characterized and exposed to deionized water and sodium sulfate solutions. Degradation experiments were conducted under saturated and unsaturated conditions. At the end of the exposure period, microstructural alterations were investigated by microprobe analyses, scanning electron microscope observations and energy-dispersive X-ray analyses. Test results provide information on the basic aspects of various degradation phenomena, such as decalcification and external sulfate attack. Experimental results were also compared with results obtained by a numerical model. The analysis reveals that the intricate microstructural features of the degraded samples could be accurately reproduced by the model.
Cement and Concrete Research, 1999
The application of the homogenization technique to the mathematical description of the diffusion ... more The application of the homogenization technique to the mathematical description of the diffusion mechanisms in saturated cementbased materials is discussed. According to this approach, the transport and mass conservation equations are first written at the microscopic scale to describe the movement of particles in the fluid phase of the material. These equations are then averaged over the entire volume of the material. An example of the application of the homogenization technique is given. The homogenization technique is used to describe the diffusion of ions in cement-based systems. The various equations are written to consider the charged nature of the ionic particles and the coupling between the various ionic fluxes. The numerous advantages of this technique for the modeling of mass transport mechanisms in cement-based materials are discussed.
Cement and Concrete Research, 1996
... IN CEMENTBASED MATERIALS ON THE BASIS OF MIGRATION EXPERIMENTS A. Delagrave, J. Marchand and ... more ... IN CEMENTBASED MATERIALS ON THE BASIS OF MIGRATION EXPERIMENTS A. Delagrave, J. Marchand and E. Samson Concrete Canada ... The only systematic comparison between nonaccelerated and accelerated test methods has been carried out by Tang [5]. The author ...
The paper reviews approaches that have been used to model the degradation of cementitious materia... more The paper reviews approaches that have been used to model the degradation of cementitious materials exposed to aggressive aqueous environments such as pure water, acid solutions, sulfate-bearing solutions and other exposure conditions that alter the hydrated paste microstructure. The review showed that multiionic approaches are being used frequently to predict the microstructure alteration in those conditions. Some models also couple ionic transport predictions with mechanical analysis to predict the volume modifications of structures exposed to these aggressive environments.
A sensitivity analysis of the parameters involved in a multiionic reactive transport model that c... more A sensitivity analysis of the parameters involved in a multiionic reactive transport model that can be used, among other applications, to predict chloride ingress in concrete structures is presented. The analysis is based on the calculation of the elasticity of each parameter using a rigorous mathematical method. It was performed for two different test cases. The first concerns the penetration of chloride ions in saturated concrete during a simple ponding experiment while the second one involves the influence of wetting and drying cycles on chloride ingress. The analysis indicates that porosity and tortuosity (i.e. ionic diffusion coefficients) are the material parameters which have the most important impact on the model predictions. Boundary conditions were also found to have a significant influence on the output of the model. On the other hand, simulations were found to be much less affected by parameters such as the initial pore solution chemistry and the initial solid phase cont...
Materials and Structures, 2014
The Rosenblueth point estimator method is used to propagate uncertainty on stochastic parameters ... more The Rosenblueth point estimator method is used to propagate uncertainty on stochastic parameters in a multi-ionic reactive transport model for concrete degradation. The degradation mechanism that was analysed is the ingress of chlorides into concrete. This point estimator method is used because it requires a minimum number of simulations to compute means, standard deviations and skewness for the solution of the transport model. Two exposure cases are considered in this article: the first is a saturated case, and the second is an unsaturated case with wetting (4 days) and drying (3 days at 50 % relative humidity) cycles. The sodium chloride exposure during the wetting cycle of both cases was 500 mmol/L. In both cases, predictions from the model were compared to experimental results. The Rosenblueth approach yielded results comparable to Monte Carlo simulations for both saturated and unsaturated cases. The relative sensitivity of model parameters on prediction results are investigated through a sensitivity analysis. The sensitivity results show the high importance of ionic diffusion parameters and of exposure conditions, while the calculated initial mineral phases in the hydrated paste have lower importance.
Materials and Structures, 2013
Results of a statistical analysis of transport properties measurements carried out on a number of... more Results of a statistical analysis of transport properties measurements carried out on a number of concrete mixtures are presented. Migration and drying experiments were performed to evaluate the ionic diffusion coefficients and permeability of concrete mixtures. Seven concrete mixtures were tested. The mixtures were either batched under laboratory conditions or sampled from construction sites. For each mixture, approximately eighty concrete samples from a single batch were tested. Ionic diffusion coefficients were calculated by analyzing the evolution of the electrical current passing through concrete samples during the migration tests. Calculations took into account the volume of permeable pores of the materials and the pore solution chemistry. Permeability was calculated from mass loss measured during drying tests. The study indicates that the coefficient of variation of ionic diffusion coefficients is 11.1 % on average, with a maximum of 23.5%, and that the coefficient of variation of permeability is 20.6% on average, with a maximum of 37.3%. Keywords Concrete • Variability •Transport properties • Service life Accordingly, the construction industry started to develop new approaches to increase the service-life of concrete structures. Traditional prescriptive methods, still very much in use today, are in many cases replaced or combined with performance and design specification. In this approach, criteria for durability, such as a targeted service-life duration, are specified. This type of approach was progressively added to construction codes. For example, language for performance specification was incorporated in Canadian standard CSA A23.1-04 1 [9], and defined as a method for specifying a construction product in which the final outcome is given in mandatory language, in a manner that the performance requirements can be measured by accepted industry standards and methods. The Unified Facilities Guide Specification (UFGS), issued by U.S federal agencies in 2010, is another construction guide that incorporates performance-based language for new concrete construction [17]. This new trend in construction methods prompted in recent years the development of numerical tools to support asset management and decision-making to optimize design, service-life, and maintenance of new and existing structures. Reactive transport models dedicated to the prediction of chloride ingress and other deleterious species in reinforced structures became a central element of this new emphasis on long-term service-life predictions [8, 25].
Cement and Concrete Research, 2005
A description of ionic transport in unsaturated porous materials due to gradients in the electro-... more A description of ionic transport in unsaturated porous materials due to gradients in the electro-chemical potential and the moisture content is developed by averaging the relevant microscopic transport equations over a representative volume element. The complete set of equations consists of time-dependent equations for both the concentration of ionic species within the pore solution and the moisture content within the pore space. The electrostatic interactions are assumed to occur instantaneously, and the resulting electrical potential satisfies Poisson's equation. Using the homogenization technique, moisture transport due to both the liquid and vapor phases is shown to obey Richards' equation, and a precise definition of the moisture content is found. The final transport equations contain transport coefficients that can be unambiguously related to experimental quantities. The approach has the advantage of making the distinction between microscopic and bulk quantities explicit.
... Bentz01influenceof, author = {Dale P. Bentz and Eric Samson and Yannick Maltais and Jacques M... more ... Bentz01influenceof, author = {Dale P. Bentz and Eric Samson and Yannick Maltais and Jacques March and Jacques March and Dale Bentz and Eric Samsonl and Yannick ... 1, Modelling calcium leaching mechanisms in hydrated cement pastes Delagrave, GerardI, et al. - 1997. ...
ABSTRACT Calcium hydroxide is one of the main,reaction products resulting from,the hydration of P... more ABSTRACT Calcium hydroxide is one of the main,reaction products resulting from,the hydration of Portland cement,with water. It is also one of the more,soluble phases found,in hydrated cement,systems. The influence of calcium hydroxide dissolution and,its effect on the diffusion properties of hydrated cement pastes were investigated using the NIST CEMHYD3D cement,hydration and,microstructure development,model. The results of these simulations were implemented,in another numerical model,called STADIUM. This latter model,can be used to predict the transport of ions in unsaturated porous
RILEM State-of-the-Art Reports, 2012
Materials and Structures, 2006
As part of the U.S. Navy program for the Modular Hybrid Pier development, a predictive durability... more As part of the U.S. Navy program for the Modular Hybrid Pier development, a predictive durability analysis has been carried out to establish the feasibility of using lightweight aggregate concrete mixtures to achieve the 100-year design life under severe marine conditions. The long-term durability of concrete was predicted using both laboratory testing and numerical modeling.
Materials and Structures, 2003
... 158 Page 4. Samson, Marchand, Snyder ... 4.2 Non steady-state migration experiments In an att... more ... 158 Page 4. Samson, Marchand, Snyder ... 4.2 Non steady-state migration experiments In an attempt to determine chloride diffusion coefficient, Tang and Nilsson [38] proposed an analysis of migration test results based on non steady-state measurements. ...
Journal of ASTM International, 2008
Journal of Colloid and Interface Science, 1999
The main features of a numerical model aiming at predicting the drift of ions in an electrolytic ... more The main features of a numerical model aiming at predicting the drift of ions in an electrolytic solution upon a chemical potential gradient are presented. The mechanisms of ionic diffusion are described by solving the extended Nernst-Planck system of equations. The electrical coupling between the various ionic fluxes is accounted for by the Poisson equation. Furthermore, chemical activity effects are considered in the model. The whole system of nonlinear equations is solved using the finite-element method. Results yielded by the model for simple test cases are compared to those obtained using an analytical solution. Applications of the model to more complex problems are also presented and discussed.
International Journal for Numerical Methods in Engineering, 1999
The main features of a numerical model aiming at predicting the drift of ions in electrolytic sol... more The main features of a numerical model aiming at predicting the drift of ions in electrolytic solutions are presented. The mechanisms of ionic diffusion are described by solving the Nernst–Planck system of equations. The electrical coupling between the various ionic fluxes is accounted for by the Poisson equation. Two algorithms using the finite element method for spatial discretization are compared for simple test cases. One is based on the Picard iteration method while the other is based on the Newton–Raphson scheme. Test results clearly indicate that the range of application is broader for the algorithm based on the Newton–Raphson method. Selected examples of the application of the algorithm to more complex 1-D and 2-D cases are given. Copyright © 1999 John Wiley & Sons, Ltd.
Computers & Structures, 2007
This paper gives the details of the multiionic transport model STADIUM® intended to describe the ... more This paper gives the details of the multiionic transport model STADIUM® intended to describe the degradation of cement-based materials exposed to aggressive environments. The main algorithm is based on an operator splitting approach. The first part of the calculations is dedicated to solving the transport equations without considering the chemical reactions. The concentration profile of each ionic species is calculated
Cement and Concrete Research, 2004
Portland cement systems are often exposed to severe environments, and their long-term performance... more Portland cement systems are often exposed to severe environments, and their long-term performance is of concern. The main results of a comprehensive investigation of deterioration processes that may affect the behavior of Portland cement systems exposed to chemically aggressive environments is presented. As part of this investigation, well-cured cement paste discs were fully characterized and exposed to deionized water and sodium sulfate solutions. Degradation experiments were conducted under saturated and unsaturated conditions. At the end of the exposure period, microstructural alterations were investigated by microprobe analyses, scanning electron microscope observations and energy-dispersive X-ray analyses. Test results provide information on the basic aspects of various degradation phenomena, such as decalcification and external sulfate attack. Experimental results were also compared with results obtained by a numerical model. The analysis reveals that the intricate microstructural features of the degraded samples could be accurately reproduced by the model.
Cement and Concrete Research, 1999
The application of the homogenization technique to the mathematical description of the diffusion ... more The application of the homogenization technique to the mathematical description of the diffusion mechanisms in saturated cementbased materials is discussed. According to this approach, the transport and mass conservation equations are first written at the microscopic scale to describe the movement of particles in the fluid phase of the material. These equations are then averaged over the entire volume of the material. An example of the application of the homogenization technique is given. The homogenization technique is used to describe the diffusion of ions in cement-based systems. The various equations are written to consider the charged nature of the ionic particles and the coupling between the various ionic fluxes. The numerous advantages of this technique for the modeling of mass transport mechanisms in cement-based materials are discussed.
Cement and Concrete Research, 1996
... IN CEMENTBASED MATERIALS ON THE BASIS OF MIGRATION EXPERIMENTS A. Delagrave, J. Marchand and ... more ... IN CEMENTBASED MATERIALS ON THE BASIS OF MIGRATION EXPERIMENTS A. Delagrave, J. Marchand and E. Samson Concrete Canada ... The only systematic comparison between nonaccelerated and accelerated test methods has been carried out by Tang [5]. The author ...