Micro-spectroscopic investigations of the Al and S speciation in - - PowerPoint PPT Presentation

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Micro-spectroscopic investigations of the Al and S speciation in - - PowerPoint PPT Presentation

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Nuclear Energy and Safety Research Department Laboratory for Waste Management PAUL SCHERRER INSTITUT Micro-spectroscopic investigations of the Al and S speciation in hardened cement paste 1 ,R. Dhn 1 , B. Lothenbach 2 , M. Vespa 1 E.

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SLIDE 1

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Micro-spectroscopic investigations

  • f the Al and S speciation in

hardened cement paste

  • E. Wieland

1,R. Dähn 1, B. Lothenbach 2, M. Vespa 1

2th International Workshop on Waste/Cement Interactions October 12-16, Le Croisic, France

1 Paul Scherrer Institute, Laboratory for Waste Management, Villigen PSI, Switzerland 2 Empa, Laboratory for Concrete & Construction Chemistry, Dübendorf, Switzerland

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SLIDE 2

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Layout

Introduction Materials and methods Al and S speciation in cementitious materials

  • Al speciation
  • References
  • Micro-spectroscopic studies
  • S speciation
  • References
  • Micro-spectroscopic studies

Conclusions

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SLIDE 3

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Background

Waste package (cement & steel) Deep geological repository Container (concrete, mortar, steel) Cavern backfill (porous mortar)

Cement – important component of the engineered barrier system of the repositories for low- (L/ILW) and intermediate-level wastes (ILW)

Hardened cement paste: ~ 20 wt%

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SLIDE 4

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

50µm Inner CSH Outer CSH Portlandite Belite Belite Ni spot

100 µm 100 µm

µ-XRF/ALS Ni, Ca BSE-image

Combination of BSE (SEM) with µ-XRF/XAS Information on the morphology and the chemical composition of

phases on the same spot

µ-XRF/LUCIA Si µ-XRF/LUCIA Al

100 µm 100 µm

BSE-image

Example: Ni uptake by cement

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SLIDE 5

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Motivation

X-ray absorption fine structure (XAFS)

spectroscopy as complementary tool to XRD for cement phase characterization?

In situ identification of single cement phases

with micro-scale resolution in hardened cement paste?

Identification of uptake-controlling cement

phase in connection with metal cation and anion binding in hardened cement paste?

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SLIDE 6

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Hardened Cement Paste (HCP)

Sulphate-resisting cement: CEM I 52.5 N HTS

Clinker phases in non hydrated cement wt%: Alite 3CaO⋅SiO2 61 Belite 2CaO⋅SiO2 18 Aluminate 3CaO⋅Al2O3 3.9 Ferrite 4CaO⋅Al2O3⋅Fe2O3 5.8 Calcite CaCO3 3.7 Gypsum, Anhydrite CaSO4 3.6 Others ≤ 4 Hydration products in wt% (w/c = 0.4; 1 y hydration): Calcium silicate hydrate (C-S-H) ~49 Portlandite ~20 Calcium aluminates (AFt, AFm) ~19 Hydrotalcite ~2 CaCO3 ~2 Minor phases (Fe, Mn oxides) <1 Non-hydrated clinker minerals ~8

plain light crossed polars

+ H2O

Lothenbach & Wieland 2006

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SLIDE 7

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Materials

References

  • S: Gypsum CaSO4
  • Al: Aluminate C3A
  • Al: Ferrite C4AF
  • Al/S: Ettringite, Fe-Ettringite
  • Al/S: AFm (C4AH13), Monosulfate, Monocarbonate
  • Al: Hydrogarnet, Si-Hydrogarnet
  • Al: Hydrotalcite

Cement

  • CEM I 52.5 N HTS (Lafarge, France)

Hardened cement pastes (HCP)

  • HTS cement hydrated at 5°, 20°, and 50° for 28 days
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SLIDE 8

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Sample Preparation for Micro and Bulk XAS Studies

Hydration Cement 5°/20°/50°

µ-XRF/XAS @ Lucia/SLS Beamsize: ~5 x 5 µm2 Thin sections

  • f HCP

dry, impregnate, cut, polish

References Clinkers (<63µm) „Bulk“-XAS @ Lucia/SLS

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SLIDE 9

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Sample Preparation

Powder materials Thin sections

Incident beam Fluorescence radiation Pellets Incident beam Fluorescence radiation Silver spot Glass support Note: Probed volume at the given energy: ~5×5×1 µm3

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SLIDE 10

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

X-ray Absorption Fine Structure (XAFS) Spectroscopy

I0 I = eµx Detection methods Transmitted beam Fluorescence X-ray photons Incident X-ray beam

LIII

2p 6d

e-

Photon - Matter interaction Spectra - regions

0,2 0,4 0,6 0,8 1 17600 17800 18000 18200 18400 18600 18800

E ( eV) Absorption

XANES region EXAFS region Edge Absorption (µx) Photon energy (E)

γ

Fluorescence

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SLIDE 11

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

X-ray Absorption Fine Structure (XAFS) Spectroscopy

S K: E0 = 2472 eV

Relative Energy [eV]

Al Interference of Si edge@1839 eV with the Al EXAFS

  • 200

200 400 600 800 1000

Absorption a.u X-ray Absorption Near Edge Structure; XANES Extended X-ray Absorption Fine Structure, EXAFS Pre-edge

Al K: E0 = 1559.6 eV

E0: photoelectron threshold energy

S limited structural information

  • n the chemical environment
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SLIDE 12

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

XANES Data Analysis

Features

  • XANES range: to an energy of about 50 eV above the edge
  • XANES states: Excited electron populate higher unoccupied states

(unoccupied bound states and low-lying continuum states in complex ions etc.)

  • XANES regime: - electronic and geometric structure
  • multiple-scattering events
  • average valence of absorber atom

Experimental consistency checks

  • Same reference measured on different campaigns
  • Same compounds prepared by different groups
  • Spectra of similar compounds
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SLIDE 13

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Reproducibility

Si-Hydrogarnet:

  • Two campaigns in June 2007 and April 2008 at

the Lucia beamline@SLS

  • 1

1 2 3 4 1.56 1.58 1.6 1.62 1.64 1.66

Si-Hydrogarnet (Jun 07) Si-Hydrogarnet (Apr 08)

Normalized Absorbance Energy [keV]

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SLIDE 14

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Variability in C3A

C3A:

  • XANES data of C3A prepared in different laboratories

0.5 1 1.5 2 2.5 1.56 1.58 1.6 1.62 1.64 1.66

C3A_PSI C3A_TM

Normalized Absorbance Energy [keV]

Matschei et al. 2007

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SLIDE 15

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Consistency of AFt Spectra

Fe-ettringite: - Spectrum of Al/Fe-ettringite-ss

  • Spectrum calculated based on ettringite

0.5 1 1.5 2 2.5 3 1.56 1.58 1.6 1.62 1.64 1.66 Fe-Ettringite Abs (au) Ettringite spectrum - corrected Fe-ettringite

Normalized Absorbance Energy [keV]

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SLIDE 16

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Aluminium speciation

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SLIDE 17

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

1E-3 0.01 0.1 1 10 100 1000 5 10 15 20 25 30 35 40 45 50 55 60 65 70 pore solution

5 °C

hydrotalcite calcite ettringite monocarbonate portlandite C-S-H gypsum C4AF C3A C2S C3S cm

3/100 g cement

hydration time [days]

HTS Modelling

Lothenbach et al. 2007

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SLIDE 18

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

1E-3 0.01 0.1 1 10 100 1000 5 10 15 20 25 30 35 40 45 50 55 60 65 70 pore solution

20 °C

hydrotalcite calcite ettringite monocarbonate portlandite C-S-H gypsum C4AF C3A C2S C3S cm

3/100 g cement

hydration time [days]

HTS Modelling

Lothenbach et al. 2007

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SLIDE 19

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

1E-3 0.01 0.1 1 10 100 1000 5 10 15 20 25 30 35 40 45 50 55 60 65 70 pore solution

50 °C

hydrotalcite calcite ettringite monosulfate portlandite C-S-H gypsum C4AF C3A C2S C3S cm

3/100 g cement

hydration time [days]

HTS Modelling

Lothenbach et al. 2007

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SLIDE 20

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

References - Hydrogarnets

Si-hydrogarnet: C3ASH4 Hydrogarnet: C3AH6

1 2 3 4 5 1.56 1.58 1.6 1.62 1.64 1.66 6

Si-Hydrogarnet Hydrogarnet

Normalized Absorbance Energy [keV]

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SLIDE 21

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

References - Ettringite

Ettringite: Ca6Al2(SO4)3(OH)12·26H2O Al/Fe-Ettringite-ss: Ca6(Al/Fe)2(SO4)3(OH)12·26H2O

0.5 1 1.5 2 2.5 3 1.56 1.58 1.6 1.62 1.64 1.66

Ettringite Fe-Ettringite

Normalized Absorbance Energy [keV]

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SLIDE 22

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

References - AFm-Phases

AFm - C4AH13: Ca4Al2(OH)14·6H2O AFm - Monocarbonate: Ca4Al2CO3(OH)12·5H2O AFm - Monosulfate: Ca4Al2SO4(OH)12·6H2O

1 2 3 4 1.56 1.58 1.6 1.62 1.64 1.66

AFm AFm-Monocarbonate AFm-Monosulfate

Normalized Absorbance Energy [keV]

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SLIDE 23

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Ettringite - AFM-Phases - Comparison

Ettringite: Ca6Al2(SO4)3(OH)12·26H2O AFm - C4AH13: Ca4Al2(OH)14·6H2O AFm - Monosulfate: Ca4Al2SO4(OH)12·6H2O

1 2 3 4 1.56 1.58 1.6 1.62 1.64 1.66

Ettringite AFM - C4AH13 AFM - Ca-monosulfo- aluminate

Normalized Absorbance Energy [keV]

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SLIDE 24

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

References - XANES data

1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance Energy [keV]

C 3A C 4AF Ettringite AFm - C

4AH 13

AFm - Monocarbonate Hydrogarnet Si-Hydrogarnet Hydrotalcit

⇒ Shift of 3 eV between clinker minerals and secondary phases

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SLIDE 25

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

References - XANES data

1.55 1.56 1.57 1.58 1.59 1.6

Normalized Absorbance Energy [keV]

C3A C4AF Ettringite AFm - C 4AH13 AFm - Monocarbonate Hydrogarnet Si-Hydrogarnet Hydrotalcit

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SLIDE 26

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Conclusions

Possible:

  • Clinker minerals - AFt/AFm - Hydrogarnets - Hydrotalcite

Difficult:

  • AFm - C4AH13 against AFm - Ca monocarbo/sulfoaluminates
  • AFt (Ettringite) against AFm-type phases

Impossible:

  • AFm - Ca monocarboaluminate and Ca monosulfoaluminate
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SLIDE 27

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Clinkers

Cem 4234: - Portland cement (Lothenbach et al. 2008) HTS 2000/2004: - Cem I 52.5 N HTS (Lafarge, France)

1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance Energy [keV]

C

3A

C

4AF

HTS 2000 HTS 2004 Cem 4234

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SLIDE 28

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Clinkers

Linear combination:

  • 40 % C3A and 60 % C4AF based on chemical

analyses

0.5 1 1.5 2 2.5 1.56 1.58 1.6 1.62 1.64 1.66 HTS 2000 HTS 2004 C

3A

40 % C3A and 60 % C4AF

Normalized Absorbance Energy [keV]

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SLIDE 29

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

MicroXRF maps - Elemental distribution

high Al S Mg Si low low high

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SLIDE 30

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

HTS 20° 28 d

low high Al

100 µm 100 µm Silver spot Silver spot

3 4 7 9 6 1 2 8 5 10 11 3 4 7 9 6 1 2 8 5 10 11

Al Si

Spot 7: high Al, high Si Spot 8: high Al, low Si Spot 9: high Al, low Si Spot 10: low Al, high Si Spot 11: low Al, low Si Spot 1: high Al, medium Si Spot 2: high Al, medium Si Spot 3: high Al, low Si Spot 4: medium Al, high Si Spot 5: high Al, medium Si Spot 6: high Al, low Si

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SLIDE 31

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

XANES HTS 20° 28d

1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance (a.u) Energy [keV]

Spot 1 Spot 2 Spot 3 Spot 4 Spot 5 Si-Hydrogarnet Ettringite C

3A

Spot 6 1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance (a.u) Energy [keV]

Spot 7 Spot 8 Spot 9 Spot 10 Spot 11 Si-Hydrogarnet Ettringite C

3A

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SLIDE 32

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

HTS 5° 28 d

Al S low high

2 1 3 4 5 6 7 8

100 µm

2 1 3 4 5 6 7 8

100 µm

Spot 1: high Al, low S Spot 2: medium Al, low S Spot 3: low Al, high S Spot 4: high Al, medium S Spot 5: medium Al, low S Spot 6: high Al, low S Spot 7: high Al, low S Spot 8: medium Al, medium S

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SLIDE 33

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

XANES HTS 5° 28d

1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance (a.u) Energy [keV]

Spot 1 Spot 2 Spot 3 Spot 4 Si-Hydrogarnet Ettringite C

3A

1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance (a.u) Energy [keV]

Spot 5 Spot 6 Spot 7 Spot 8 Si-Hydrogarnet Ettringite C

3A

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SLIDE 34

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

HTS 50° 28 d

100 µm 100 µm 100 µm

3 1 12 8 2 9 10 6 11 5 4 7

Al

3 1 12 8 2 9 10 6 11 5 4 7

Si low high

Spot 7: high Al, low Si Spot 8: low Al, medium Si Spot 9: high Al, medium Si Spot 10: high Al, medium Si Spot 11: high Al, medium Si Spot 12: high Al, low Si Spot 1: high Al, low Si Spot 2: medium Al, medium Si Spot 3: medium Al, low Si Spot 4: high Al, medium Si Spot 5: low Al, medium Si Spot 6: medium Al, low Si

slide-35
SLIDE 35

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

XANES HTS 50° 28d

1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance (a.u) Energy [keV]

Spot 1 Spot 2 Spot 3 Spot 4 Si-Hydrogarnet Ettringite C

3A

Spot 7 Spot 6 1.56 1.58 1.6 1.62 1.64 1.66

Normalized Absorbance (a.u) Energy [keV]

Spot 5 Spot 8 Spot 9 Spot 10 Si-Hydrogarnet Ettringite C

3A

Spot 12 Spot 11

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SLIDE 36

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Principal Components Analysis (PCA)

PCA

Analyse a set of spectra to see if they can be represented as linear

combination of a smaller number of spectra (abstract components)

D = C × R

(m × r) (m × n) (n × r)

D: Data matrix which is factored into its components C: Factor loading matrix R: Factor-score matrix

Target transformation

Determine which real reference can make up the abstract component SPOIL – number which measures the degree to which replacing an

abstract component with the real reference would increase the fit error

SPOIL < 1.5: reference is an excellent candidate for a component SPOIL 1.5 - 3: reference is a good candidate for a component SPOIL 3 - 4.5: reference is a fair candidate for a component SPOIL 4.5 - 6: reference is a poor candidate for a component

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SLIDE 37

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Principal Components Analysis

HTS 20° 28d

4-5 components (total of 11 XANES spectra - SPOIL < 4.5) C3A/AFm(C4AH13)/Ettringite/AFm-Monosulfate/Hydrotalcite/Si-Hydrogarnet

HTS 5° 28d

3 components (total of 8 XANES spectra SPOIL < 4.5) C3A/AFm(C4AH13)/Ettringite/AFm-Monosulfate/(AFm-Monocarbonate)

Hydrotalcite/Si-Hydrogarnet

HTS 50° 28d

3 components (total of 12 XANES spectra – SPOIL < 4.5) C3A/AFm(C4AH13)/Ettringite/AFm-Monosulfate/(AFm-Monocarbonate)

Hydrotalcite/Si-Hydrogarnet

slide-38
SLIDE 38

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Linear Combination

Aim:

XANES spectra as linear combination of reference spectra Minimum number of components according to PCA References selected based on the results from PCA/Target transformation

Procedure:

Linear combination tool in Athena (Iffefit) Residual: R = Fit: excellent for R ≤ 0.5; fair for R > 0.5

∑(data – fit)2 ∑(data)2 ×100%

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SLIDE 39

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

HTS 5° 28 d

0.5 1 1.5 2 1.56 1.58 1.6 1.62 1.64 1.66

model experimental data

Normalized Absorbance (a.u) Energy [keV]

  • 0.5

0.5 1 1.5 2 2.5 1.56 1.58 1.6 1.62 1.64 1.66

model experimental data

Normalized Absorbance (a.u) Energy [keV]

Spot 5 (R =0.67) Spot 8 (R = 0.21)

slide-40
SLIDE 40

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Linear Combination HTS 5°

Spot C3A C4AF Ettringite AFm Hydro- talcite Res %

# 1 75 % 25 % 0.60 # 2 78 % 22 % 0.42 # 3 66 % 34 % 0.31 # 4

  • # 5

67 % 25 % 8 % 0.67 # 6 54 % 46 % 0.36 # 7 84 % 16 % 0.70 # 8 54 % 46 % 0.21

slide-41
SLIDE 41

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Linear Combination HTS 20°

Spot C3A C4AF Ettringite AFm Hydro- talcite R

# 1 74 % 26 % 0.43 # 2 75 % 26 % 0.34 # 3 64 % 36 % 0.28 # 4 50 % 50 % 0.47 # 5 81 % 19 % 0.71 # 6 80 % 13 % 7 % 0.46 # 7 71 % 2% 27 % 0.65 # 8 68 % 23 % 9 % 0.2 % 0.32 # 9 51 % 26 % 11 % 12% 0.27 # 10 74 % 1 % 25 % 0.40 # 11 76 % 24 % 0.67

slide-42
SLIDE 42

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Linear Combination HTS 50°

Spot C3A C4AF Ettringite AFm Hydro- talcite R

# 1 66 % 29 % 5 % 0.75 # 2 56 % 44 % 0.36 # 3 71 % 24 % 5 % 0.77 # 4 54 % 38 % 8 % 0.27 # 5 60 % 40 % 0.40 # 6 55 % 33 % 12 % 1.0 # 7 57 % 27 % 16 % 0.91 # 8 50 % 48 % 2 % 0.32 # 11 65 % 35 % 0.81 # 9 54 % 46 % 0.39 # 10 66 % 34 % 0.44 # 12 60 % 32 % 8 % 0.41

slide-43
SLIDE 43

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Sulfur speciation

slide-44
SLIDE 44

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Sulfur - References

2 4 6 8 2.47 2.48 2.49 2.5 2.51 2.52 CaSO4 Ettringite Ca monosulfoaluminate

Normalized Absorbance Energy [keV]

slide-45
SLIDE 45

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

HCP Sample

HTS-50C : - HTS cement 2004 hydrated at 50° for 28 d Silver spot

Ettringite

  • r

Monosulfate Formation?

slide-46
SLIDE 46

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

MicroXRF Maps

Si

9 10 8 1 2 3 4 5 6 7

low high Al

Silver spot 100 µm

low high S

9 10 8 1 2 3 4 5 6 7 9 10 8 1 2 3 4 5 6 7

Mg

10 8 1 2 3 4 5 6 7

Silver spot 100 µm Silver spot 100 µm Silver spot 100 µm

9

slide-47
SLIDE 47

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

HTS 50° 28 d

slide-48
SLIDE 48

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Linear combination

Spot 6 (R = 0.33) Spot 2 (R = 0.23)

2.47 2.48 2.49 2.5 2.51 2.52

model experimental data

Normalized Absorbance (a.u) Energy [keV]

2.47 2.48 2.49 2.5 2.51 2.52

model experimental data

Normalized Absorbance (a.u) Energy [keV]

slide-49
SLIDE 49

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Linear Combination HTS 50°

Spot CaSO4 Ettringite Monosulfate Res %

# 1 32 % 68 % 0.76 # 2 38 % 62 % 0.23 # 3 14 % 86 % 0.36 # 4 24 % 76 % 0.37 # 5 16 % 84 % 0.37 # 6 39 % 61 % 0.33 # 7 33 % 67 % 0.34 # 8 100 % 1.3 # 9 38 % 62 % 0.46 # 10 35 % 65 % 0.33

slide-50
SLIDE 50

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Conclusions

Micro-spectroscopic approach to phase identification

  • Allows cement phases to be identified with micro-scale resolution
  • Requires good quality data (references, spectra from single spots) as

single cement phases have to extracted from complex mixtures Al speciation

  • High content of C3A at hot spots
  • C3A and ettringite as dominating Al species in cement paste hydrate

for 28 days at 5°

  • C3A, ettringite and AFm phases present in cement paste hydrated for

28 days at 20° and 50° S speciation

  • Predominantely Ca monosulfoaluminate and some ettringite is
  • bserved in cement paste hydrated for 28 days at 50°
  • Presence of Ca monosulfoaluminate consistent with thermodynamic

modelling

  • More sensitve with regards to distinction of ettringite and monosulfate
slide-51
SLIDE 51

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Acknowledgements

Synthesis of references

  • T. Matschei
  • L. Aimoz
  • G. Möschner
  • K. Rozov

Beamline Lucia @ SLS/PSI Partial financial support by the National Cooperative for the Disposal of Radioactive Waste (Nagra), Switzerland.

slide-52
SLIDE 52

Paul Scherrer Institut CH-5232 Villigen PSI WCI-2 2008

PAUL SCHERRER INSTITUT

Nuclear Energy and Safety Research Department Laboratory for Waste Management

Thank you for your attention!