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Concrete durability: physical chemistry of the water attack; Durabilite du beton: physico-chimie de l`alteration par l`eau

Abstract

Cement paste constitutes an basic medium, thermodynamically stable for high pH`s. For this reason, water constitutes an aggressive environment. For hydraulic structures, or nuclear waste disposal, water must be considered as a `chemical loading`. In the short- and medium-term water-degradation of cement paste is principally due to transport of matter between the healthy zone and the aggressive solution through diffusion of ionic species from the interstitial solution of the cement paste. In the long-term, dissolution of the surface may occur. Various cement pastes were prepared and leached with continually demineralized water. After a critical time, which depends on the type of paste, the dissolution of the surface layer in contact with water will control the degradation kinetics. The diffusive and chemical properties of the degraded layer are therefore fundamental for the prediction of the long-term behaviour of concrete in water. {sup 29}Si Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) combined with {sup 27}A1 MAS NMR and {sup 57}Fe Moessbauer spectroscopy indicate that the superficial layer is formed by a CSH with a molecular structure near from the tobermorite mineral. Nuclear magnetic resonance techniques allow us to demonstrate the fundamental role of cationic substitutions occurring in the CSH during degradation  More>>
Authors:
Publication Date:
Jan 22, 1997
Product Type:
Thesis/Dissertation
Report Number:
FRCEA-TH-596
Reference Number:
SCA: 360604; PA: AIX-29:025525; EDB-98:061061; SN: 98001959750
Resource Relation:
Other Information: TH: These (D. es Sc.).; PBD: 22 Jan 1997
Subject:
36 MATERIALS SCIENCE; CALCIUM SILICATES; CEMENTS; CORROSION RESISTANCE; DECOMPOSITION; NUCLEAR MAGNETIC RESONANCE; RADIOACTIVE WASTE MANAGEMENT; RADIOACTIVE WASTE PROCESSING; SPECTROSCOPY; WEAR RESISTANCE
OSTI ID:
606363
Research Organizations:
Institut National des Sciences et Techniques Nucleaires (INSTN) - Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France); Universite de Cergy Pontoise, 95 (France).
Country of Origin:
France
Language:
French;English
Other Identifying Numbers:
Other: ON: DE98622093; TRN: FR9703945025525
Availability:
INIS; OSTI as DE98622093
Submitting Site:
FRN
Size:
259 p.
Announcement Date:
Jun 17, 1998

Citation Formats

Faucon, P. Concrete durability: physical chemistry of the water attack; Durabilite du beton: physico-chimie de l`alteration par l`eau. France: N. p., 1997. Web.
Faucon, P. Concrete durability: physical chemistry of the water attack; Durabilite du beton: physico-chimie de l`alteration par l`eau. France.
Faucon, P. 1997. "Concrete durability: physical chemistry of the water attack; Durabilite du beton: physico-chimie de l`alteration par l`eau." France.
@misc{etde_606363,
title = {Concrete durability: physical chemistry of the water attack; Durabilite du beton: physico-chimie de l`alteration par l`eau}
author = {Faucon, P}
abstractNote = {Cement paste constitutes an basic medium, thermodynamically stable for high pH`s. For this reason, water constitutes an aggressive environment. For hydraulic structures, or nuclear waste disposal, water must be considered as a `chemical loading`. In the short- and medium-term water-degradation of cement paste is principally due to transport of matter between the healthy zone and the aggressive solution through diffusion of ionic species from the interstitial solution of the cement paste. In the long-term, dissolution of the surface may occur. Various cement pastes were prepared and leached with continually demineralized water. After a critical time, which depends on the type of paste, the dissolution of the surface layer in contact with water will control the degradation kinetics. The diffusive and chemical properties of the degraded layer are therefore fundamental for the prediction of the long-term behaviour of concrete in water. {sup 29}Si Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) combined with {sup 27}A1 MAS NMR and {sup 57}Fe Moessbauer spectroscopy indicate that the superficial layer is formed by a CSH with a molecular structure near from the tobermorite mineral. Nuclear magnetic resonance techniques allow us to demonstrate the fundamental role of cationic substitutions occurring in the CSH during degradation on the superficial layer solubility. Our experimental results were used to model the cement paste behaviour taking into account the diffusion and the dissolution of the material. (author).}
place = {France}
year = {1997}
month = {Jan}
}