Modelling of concrete/clay interaction : taking into account complex mineralogy influence of non-saturated conditions and temperature effects F. Claret, A. Burnol, S. Gaboreau, N. Marty, C.Tournassat, P.Blanc, EC. Gaucher BRGM, Orléans With the partnership of: Andra: X. Bourbon, S. Dewonck, I. Munier, N. Michau 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le Croisic, October 12-16,2008
CONTEXT: COX/CONCRETE/BENTONITE INTERACTION F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 2
MODELLING AS A TOOL > To size a future underground experiment in the Bure’s Laboratory • MLH experiment (see S.DEWONCK’s poster) • pH evolution of an alkaline solution in contact with the COX 13.5 13 12.5 12 11.5 1L 3L 11 5L 10.5 10L pH 15L 10 9.5 9 8.5 8 7.5 7 6.5 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 3.75 4 4.25 4.5 4.75 5 5.25 5.5 5.75 6 Temps (années) > To make some predictive calculations • Long term modelling of concrete/clay interactions for PA purposes F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 3
CRITICAL ELEMENTS FOR THE MODELLING > A coherent thermodynamic database to work in temperature > A “complete” mineralogical description of the initial system > Transport parameters (porosities, permeabilities, diffusion coefficients, heat conductivities…) > A Transport reactive code • PHREEQC (1D) • TOUGHREACT (radial geometry, non saturated condition, ….) > Experiments to test and improve the modelling > …. F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 4
CRITICAL ELEMENTS FOR THE MODELLING > A coherent thermodynamic database to work in temperature > A “complete” mineralogical description of the initial system > Transport parameters (porosities, permeabilities, diffusion coefficients, heat conductivities…) > A Transport reactive code • PHREEQC (1D) • TOUGHREACT (radial geometry, non saturated condition, ….) > Experiments to test and improve the modelling > …. F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 5
http://thermoddem.brgm.fr/ F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 6
AMORPHOUS CSH > Among the various models published that take into account the solubility of CSH, two main families may be distinguished: • Discrete phases • Solid solutions > Nowdays integration of solid solutions in transport geochemical codes lead to crippling computing times F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 7
COMPOSITION OF AMORPHOUS CSH PHASES (1/4) > According to the literature and given the crystallographic constraints a 3-phases model was chosen > Such model already exist (CSH0.8/1.1/1.8) • Stronach and Glasser (1997) Adv. Cem. Res. Vol. 36 pp.167 • A.C. Courault (2000) Thesis Université de Bourgogne > Strategy used : fitting of the literatures data with a least squares algorithm F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 8
COMPOSITION OF AMORPHOUS CSH PHASES (2/4) Courault [15] Grutzeck et al. [49] 2.5 Fuji and Kondo [55] Greenberg and Chang [48] Kalousek [56] Taylor [51] Roller and Erwin [54] Flint and Wells [47] 2.0 Ca/Si in solid 2 1.5 1.0 0.5 0.0 0 5 10 15 20 Dissolved Ca (in mmol/l) Dispersion in the values can be link to : � The synthesis route followed � The pathway followed to reach equilibrium (by dissolution or precipitation) � The assessment of the C/S ratio in the solid � A solid/liquid equilibrium not reached due to kinetic constraints F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 9
COMPOSITION OF AMORPHOUS CSH PHASES (3/4) Courault [15] Grutzeck et al. [49] 2.5 Fuji and Kondo [55] Greenberg and Chang [48] Kalousek [56] Taylor [51] Roller and Erwin [54] Flint and Wells [47] 2.0 Ca/Si in solid 2 1.5 C/S = 1.6 ± 0.1 1.0 C/S = 1.2 ± 0.18 C/S = 0.8 ± 0.16 0.5 0.0 0 5 10 15 20 Dissolved Ca (in mmol/l) Blanc, P. et al. accepted. Chemical conceptual model for cement-based materials: Thermodynamic data assessment of stoichiometric and non- stoichiometric CSH phases. J.Hazardous.Materials F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 10
COMPOSITION OF AMORPHOUS CSH PHASES (3/4) Courault [15] Grutzeck et al. [49] 2.5 Fuji and Kondo [55] Greenberg and Chang [48] Kalousek [56] Taylor [51] Roller and Erwin [54] Flint and Wells [47] 2.0 Ca/Si in solid 2 1.5 1.0 C/S = 1.6 0.1 C/S = 1.8 C/S = 1.2 0.18 C/S = 1.1 0.5 C/S = 0.8 0.16 C/S = 0.8 0.0 0 5 10 15 20 Dissolved Ca (in mmol/l) F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 11
COMPOSITION OF AMORPHOUS CSH PHASES (4/4) Flint and Wells [47] Roller et Ervin, 1940 Taylor [51] 10 Kalousek [56] Greenberg and Chang [48] Fuji and Kondo [55] Courault [15] 1 Grutzeck et al. [49] Dissolved Si (mmol/l) CSH1.6/CSH0.8 solid solution 0.1 CSH0.8 0.01 CSH1.2 CSH1.6 0.001 0 5 10 15 20 25 Dissolved Ca (mmol/l) F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 12
CRYSTALLINE CSH PHASES (1/2) Xonotlite Hillebrandite 200 � Temperature transition to low Portlandite � Authors see this phase at least up to 200° C Temperature (ºC) 150 � Foshagite considered as C) high temperature phase Temperature (° Foshagite C) Tobermorite-11A T (° � Absence of okenite, afwillite and jennite 100 Gyrolite 50 Quartz Tobermorite-14A 0 10 12 14 16 18 20 22 24 log a Ca ++ /H + .2.0 Log(a Ca++ ) – 2 log(a H+ ) Log(a Ca++ )-2log(a H+ ) blanc Fri Jun 15 2007 Diagram calculated using the estimates of Babushkin et al. (EQ3.6) F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 13
CRYSTALLINE CSH PHASES (2/2) Xonotlite Hypotheses : Hillebrandite 200 Xonotlite Portlandite � Use of triple point (Gibbs phases rule) � � H of Tobermorite 11A° , Xonotlite, Temperature (ºC) 150 Foshagite Hillebrandite C) Tobermorite_ 11 A Temperature (° and Hillebrantite are fixed C) � The Cp of Babushkin were used Tobermorite-11A T (° Gyrolite 100 Gyrolite Afwillite Quartz,alpha Afwillite 50 Tobermorite_ 14 A Jennite Jennite Quartz Tobermorite-14A 0 10 12 14 16 18 20 22 24 log a Ca ++ /H + .2.0 Log(a Ca++ ) – 2 log(a H+ ) Log(a Ca++ )-2log(a H+ ) blanc Thu Jun 28 2007 Blanc, P. et al. accepted. J.Hazardous.Materials F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 14
CRITICAL ELEMENTS FOR THE MODELLING > A coherent thermodynamic database to work in temperature > A “complete” mineralogical description of the initial system > Transport parameters (porosities, permeabilities, diffusion coefficients, heat conductivities…) > A Transport reactive code • PHREEQC (1D) • TOUGHREACT (radial geometry, non saturated condition, ….) > Experiments to test and improve the modelling > …. F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 15
STARTING MINERALOGICAL CONDITIONS (CONCRETE) Amorphous hypothesis @ 25ºC (1) Hyp1 Hyp2 Cristalline hypothesis @ 25ºC (2) Pore water composition after resaturation with COX pore water CEM I + calcite aggregate F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 16
STARTING MINERALOGICAL CONDITIONS (COX) 100 Concentrations (mmol/L) 10 1 0.1 • PAC experiment 0.01 0.001 Fe Si Sr K Mg Ca Na Cl S(6) TIC F.CLARET EPI/MIS Gaucher et al. Submitted to GCA 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 17
STARTING MINERALOGICAL CONDITIONS (MX80 bentonite) 70% MX80 + 30% Sand F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 18
CRITICAL ELEMENTS FOR THE MODELLING > A coherent thermodynamic database to work in temperature > A “complete” mineralogical description of the initial system > Transport parameters (porosities, permeabilities, diffusion coefficients, heat conductivities…) > A Transport reactive code • PHREEQC (1D) • TOUGHREACT (radial geometry, non saturated condition, ….) > Experiments to test and improve the modelling > …. F.CLARET EPI/MIS 2 nd International Workshop: Mechanisms and modelling of waste/cement interactions, Le croisic, October 12-16, 2008 > 19
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