Modelling of leaching in pure cement paste and mortar

Mainguy, M.; Tognazzi, C.; Torrenti, Jean‐Michel; Adenot, F.

doi:10.1016/s0008-8846(99)00208-2

Cited by 210 publications

(113 citation statements)

References 5 publications

Supporting

Mentioning

103

Contrasting

Unclassified

Order By: Relevance

“…The effective diffusion coefficient D i (dm 2 s −1 ) of each species i is calculated taking into account the porosity changes as well as the degree of saturation. For a saturated cement paste, (Tognazzi and Ollivier, 1998;Mainguy et al, 2000) proposed an empirical relationship between the effective diffusion coefficient and the porosity of sound materials. For φ<0.92, we have:…”

Section: Transport Of Aqueous Speciesmentioning

confidence: 99%

Reactive transport modeling of CO2 through cementitious materials under CO2 geological storage conditions

Shen

2013

International Journal of Greenhouse Gas Control

View full text Add to dashboard Cite

RésuméUn modèle de transport réactif est proposé pour simuler la réactivité des matériaux à base de ciment en contact avec une saumure saturée en CO 2 et/ou le CO 2 supercritique (CO 2 sc) dans les conditions de stockage géologique du CO 2 . Un code a été développé pour résoudre simultanément le transport et la chimie par une approche globale couplée, compte tenu de l'effet de la température et de la pression.La variabilité des propriétés du CO 2 sc avec la pression et la température, telles que la solubilité dans l'eau, la densité et la viscosité sont pris en compte. On suppose que tous les processus chimiques sont en équilibre thermodynamique. Les réactions de dissolution et de précipitation de la portlandite (CH) et Ce modèle est en mesure de simuler les processus de carbonatation des matériaux à base de ciment, dans des conditions à la fois saturés et insaturés, dans une large plage de concentration de CO 2 , de température et de pression. Plusieurs expériences, rapportées dans la littérature, sont simulées en utilisant divers types de conditions aux limites: (i) solutions saturées ou non en CO 2 et carbonate de calcium, (ii) gas supercritique de CO 2 . Les prédictions sont comparées avec les observations expérimentales. Certains II phénomènes observés expérimentalement peuvent être également expliqués par le modèle. Mots-clés:Carbonatation, CO 2 supercritique, Transports, Ciment, C-S-H, Décalcification, Pression, Température, Stockage du CO 2 . AbstractA reactive transport model is proposed to simulate the reactivity of cement based material in contact with CO 2 -saturated brine and supercritical CO 2 (scCO 2 ) under CO 2 geological storage conditions. This code is developed to solve simultaneously transport and chemistry by a global coupled approach, considering the effect of temperature and pressure.The variability of scCO 2 properties with pressure and temperature, such as solubility in water, density and viscosity are taken into account. It is assumed that all chemical processes are in thermodynamical equilibrium. Dissolution and precipitation reactions for portlandite (CH) and calcite (CC) are described by mass action laws and threshold of ion activity products in order to account for complete dissolved minerals. A chemical kinetics for the dissolution and precipitation of CH and CC is introduced to facilitate numerical convergence. One properly chosen variable is able to capture the precipitation and dissolution of the relevant phase. A generalization of the mass action law is developed and applied to calcium silicate hydrates (C-S-H) to take into account the continuous variation (decrease) of the Ca/Si ratio during the dissolution reaction of C-S-H. The changes in porosity and microstructure induced by the precipitation and dissolution reactions are also taken into account.Couplings between transport equations and chemical reactions are treated thanks to five mass balance equations written for each atom (Ca, Si, C, K, Cl) as well as one equation for charge balance and one for the total mass. Ion tran...

show abstract

Section: Transport Of Aqueous Speciesmentioning

confidence: 99%

Reactive transport modeling of CO2 through cementitious materials under CO2 geological storage conditions

Shen

2013

International Journal of Greenhouse Gas Control

View full text Add to dashboard Cite

show abstract

“…Turning now to D * (θ), we observe that many other studies of water transport in concrete and related porous media [5,25,39,36] approximate the diffusivity by an exponential function of saturation…”

Section: Moisture Diffusion Coefficientmentioning

confidence: 92%

A model for reactive porous transport during re-wetting of hardened concrete

Chapwanya

Liu

2009

J Eng Math

View full text Add to dashboard Cite

A mathematical model is developed that captures the transport of liquid water in hardened concrete, as well as the chemical reactions that occur between the imbibed water and the residual calcium silicate compounds residing in the porous concrete matrix. The main hypothesis in this model is that the reaction product -calcium silicate hydrate gel -clogs the pores within the concrete thereby hindering water transport. Numerical simulations are employed to determine the sensitivity of the model solution to changes in various physical parameters, and compare to experimental results available in the literature.

show abstract

“…The Finite Volume method [4] seems to be particularly accurate for our concern. Indeed it is well adapted to diffusion problems because its equations remain conservative.…”

Section: Calcium Leaching Modellingmentioning

confidence: 99%

Probabilistic modelling of calcium leaching in a tunnel for nuclear waste disposal

Larrard

Benboudjema

Colliat

et al. 2011

EPJ Web of Conferences

View full text Add to dashboard Cite

Abstract. This works aims at studying, through the Monte-Carlo method, the influence of the leaching kinetics parameters spatial variability on the lilfespan of a concrete structure. The considered structure is a tunnel for nuclear waste disposal. It is observed that the expected value for the lifespan estimated when considering the material spatial variability is significantly lower than the lifespan estimated with a single simulation considering uniform parameters fields, equal to the expected value for each parameter.

show abstract

Modelling of leaching in pure cement paste and mortar

Cited by 210 publications

References 5 publications

Reactive transport modeling of CO2 through cementitious materials under CO2 geological storage conditions

Reactive transport modeling of CO2 through cementitious materials under CO2 geological storage conditions

A model for reactive porous transport during re-wetting of hardened concrete

Probabilistic modelling of calcium leaching in a tunnel for nuclear waste disposal

Contact Info

Product

Resources

About