Transcript The Use of Nuclear Resonance Reaction Analysis for a

NANOSCALE MEASUREMENTS OF
CEMENT HYDRATION DURING THE
INDUCTION PERIOD
Jeffrey S. Schweitzer
Department of Physics
University of Connecticut
Storrs, Ct, USA
2nd International Symposium on
Nanotechnology in Construction
Bilbao, Spain November 2005
Collaborators
• Richard A. Livingston, FHWA
• Claus Rolfs, Hans-Werner Becker, Ruhr Universität
Bochum, Germany
• Stefan Kubsky, Synchrotron SOLEIL, Saint-Aubin, Gifsur-Yvette CEDEX, France
• Timothy Spillane, University of Connecticut
• Marta Castellote Armero, Paloma G. de Viedma, IETcc
(CSIC), Madrid, Spain
• Walairat Bumrongjaroen (University of Hawaii)
• Supaluck Swatekititham (Chulalongkorn University)
Study of the Induction Period
• The details of the kinetics of the cement
curing reactions are not known
• The reactions appear to be initiated at the
grain surfaces
• Hydrogen plays a key role in the reaction
process
• Studying the change in hydrogen
concentration as a function of depth and
time will provide insight into the reactions
1.0
0.0
0.2
0.4
0.6
0.8
FREE WATER
HYDRATION
PRODUCTS
0.4
0.2
0.2
0.4
PORTLAND
CEMENT
0.6
0.8
0.0
1.0
0.1
1
10
100
LOG TIME (days)
after GLASSER et al. (1987)
REACTION PROGRESS
(Alpha)
0.6
INDUCTION
PERIOD
MASS PERCENT
0.8
FREEWATER
INDEX
W/C =0.4
Nuclear Resonant Reaction
Analysis (NRRA)
• Use of a narrow resonance (~ 1 keV) permits
good spatial resolution
• Use of inverse kinematics (a 15N beam) provide
large dE/dx, which improves spatial resolution
• A well isolated resonance provides the ability to
have deep probing of the sample (~ 2-3 microns)
• All of these are provided by the 6.4 MeV
15N(p,ag)12C reaction
Resonance cross section
d
d
10 5
10
4
10
3
1H(15N,ag)12C
10 2
10
1
10
0
10
-1
6.2
6.3
6.4
6.5
6.6
6.7
Energy (MeV)
6.8
6.9
7
Resonant Reaction Depth Profiling
Pellet Preparation
•
•
•
•
Pure triclinic C3S powder
Pressed into 13 mm dia. ring molds
Fired at 1600 ºC to fuse upper surface
Epoxied to stainless steel backing or with
no backing
• Stored under nitrogen until used
Sample Preparation
•
•
•
•
Saturated Ca(OH)2 Solution ( pH=12.5)
Isothermal (10, 20 or 30 °C )
N2 Purge of solution
Specimens removed sequentially at
specified times
• Hydration stopped using methanol rinse
• Specimens dried to 10-6 Torr vacuum
Typical Experimental Plan
Temperature
Number of Pellets
oC
10
20
30
10
4
10
Time Span
Hrs
21
5.5
2.5
Measurements
• Typical scan takes about one hour
• Chamber vacuum < 10-6
• Use of two beam charge states to cover
complete energy range to 11 MeV
• Only background in gamma-ray spectrum
is from cosmic rays
• Beam-line cold trap minimizes carbon
buildup
Beam Energy Resolution
2
Slit Gain = 2.3
Slit Gain = 1.2
Counts/charge
1.5
1
0.5
0
6.38
6.39
6.4
6.41
6.42
6.43
Beam Energy (MeV)
6.44
6.45
6.46
700
10°C, 4 Hours
Beam Energy = 6.446 MeV
600
Counts
500
400
300
200
100
0
0
2
4
6
8
Gamma Ray Energy (MeV)
10
12
Time Progression
Depth (m)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
40
3.0
2.5
Cts/Charge
2.0
1.5
1.0
1.5
20
0.5
0.0
6.4
6.5
6.6
6.7
6.8
6.9
7.0
1.0
o
Data, 30 C, 0.25 Hours
o
Data, 30 C, 0.50 Hours
10
0.5
0.0
6
7
8
9
10
Beam Energy (MeV)
11
0
12
3
30
2.0
H Concentration (mmol/cm )
2.5
Typical Scan at Early Times
Depth (m)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
40
3.0
2.5
2.5
3
H Concentration (mmol/cm )
30
2.0
Cts/Charge
2.0
1.5
1.0
1.5
20
0.5
0.0
6.4
6.5
6.6
6.7
6.8
6.9
7.0
1.0
o
Data, 30 C, 0.25 Hours
10
0.5
0.0
6
7
8
9
10
Beam Energy (MeV)
11
0
12
C3S at 30
oC
Depth (m)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
40
3.0
2.5
Cts/Charge
2.0
1.5
1.0
1.5
20
0.5
0.0
6.4
6.5
6.6
6.7
6.8
6.9
7.0
1.0
o
Data, 30 C, 0.25 Hours
o
Data, 30 C, 0.50 Hours
o
Data, 30 C, 0.75 Hours
0.5
10
0.0
6
7
8
9
10
Beam Energy (MeV)
11
0
12
3
30
2.0
H Concentration (mmol/cm )
2.5
Temperature Dependence of
Induction Time
ARRHENIUS PLOT OF INDUCTION TIMES
3.0
LN (INDUCTION TIME), Hrs
2.5
10
Data
Linear Fit
2.0
1.5
20
1.0
t = Ce
-13
C = 8.1x10 hr
Ea= 69± 4 kJ/mol
R = 0.998
Ea/RT
0.5
30
0.0
3.20
3.25
3.30
3.35
3.40
3.45
3.50
3.55
-1
RECIPROCAL TEMPERATURE, 1000/T (K )
3.60
Hydrogen Profile Pre-breakdown
Depth (m)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
40
D=1.5 X10
2.5
-10
2
3.0
cm /s
Cts/Charge
2.0
1.5
1.0
1.5
20
0.5
0.0
6.4
6.5
6.6
6.7
6.8
6.9
7.0
1.0
o
Data, 30 C, 0.75 Hours
Gaussian Peak
Constant Diffusion Constant Fit
Baseline
0.5
0.0
6
7
8
9
10
Beam Energy (MeV)
Depth (m)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
40
D=1.5 X10
2.5
-10
2
3.0
cm /s
Cts/Charge
20
6.4
6.5
6.6
6.7
6.8
6.9
7.0
o
6
7
8
9
10
Beam Energy (MeV)
11
10
0
12
3
30
1.5
1.0
0.5
0.0
Data, 30 C, 0.75 Hours
Gaussian Peak
Constant Diffusion Constant Fit
Baseline
0.5
0.0
H Concentration (mmol/cm )
2.5
2.0
2.0
1.5
1.0
11
10
0
12
3
30
2.0
H Concentration (mmol/cm )
2.5
Hydrogen Profile Post-breakdown
Depth (m)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
40
2.5
3
2.5
-12
D=8.4X10
2.0
Cts/Charge
2.0
2
30
cm /s
1.5
1.0
1.5
20
0.5
0.0
6.4
6.5
6.6
6.7
6.8
6.9
7.0
1.0
o
10
Data, 30 C, 2 Hours
Constant Diffusion Constant Fit
Baseline
0.5
0.0
0
6
7
8
9
10
Beam Energy (MeV)
Depth (m)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
40
3
2.5
-12
D=8.4X10
2.0
Cts/Charge
2
30
cm /s
1.5
1.0
1.5
20
0.5
0.0
6.4
6.5
6.6
6.7
6.8
6.9
7.0
1.0
o
10
Data, 30 C, 2 Hours
Constant Diffusion Constant Fit
Baseline
0.5
0.0
0
6
7
8
H Concentration (mmol/cm )
3.0
2.5
2.0
9
10
Beam Energy (MeV)
11
12
H Concentration (mmol/cm )
3.0
11
12
Reaction zones in hydrating C3S during the induction period.
H Concentration with Retarder and
Accelerator
6000
5500
5000
10 mmol/L Sucrose, 24 hrs
I M Calcium Chloride, 1.5 hrs
H, Gamma Counts
4500
4000
3500
3000
2500
2000
1500
1000
500
0
6
7
8
9
10
Beam Energy, MeV
11
12
Comparison of Profiles
2.0
C3S Normal (1.25 hr)
1.8
Cts/Charge
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
6.0
7.0
8.0
9.0
10.0
11.0
2.0
1.8
1.6
C3S Accelerated (1.0 hr)
Cts/Charge
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
2.0
6
7
8
9
10
11
1.8
1.6
Cts/Charge
1.4
C3S Retarded (1.25 hr)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
6
7
8
9
MeV
10
11
Comparison with Belite
2.0
C3S Normal (1.25 hr)
1.8
Cts/Charge
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
6.0
7.0
8.0
9.0
10.0
11.0
2.0
1.8
1.6
C3S Accelerated (1.0 hr)
Cts/Charge
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
2.0
6
7
8
9
10
11
10
11
1.8
1.6
Cts/Charge
1.4
Belite (1.25 hr)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
6
7
8
9
MeV
Time Dependence of Belite
Hydration Profiles
Belite
3.0
12.5 hr
Cts/Charge
2.5
11.25 hr
10 hr
8.75 hr
7.5 hr
6.25 hr
5 hr
3.75 hr
2.0
1.5
1.0
2.5 hr
1.25 hr
0.5
Unhydrated, Rinsed
Unhydrated
0.0
6.0
6.5
7.0
7.5
MeV
8.0
8.5
9.0
Highly Accelerated
C3S, 30 C, 1 M CaCl2
6500
6000
5500
5000
4500
Cts/Charge
4000
6 Hr
5 Hr
4 Hr
3 Hr
2.5 Hr
2 Hr
1.5 Hr
0.75 Hr
3500
3000
2500
2000
1500
1000
500
0
-500
C3S, 30 C, 1 M CaCl2
6500
6000
5500
5000
4500
Cts/Charge
4000
6 Hr
5 Hr
4 Hr
3 Hr
2.5 Hr
2 Hr
1.5 Hr
0.75 Hr
3500
3000
2500
2000
1500
1000
500
0
-500
6
7
8
9
MeV
10
11
6
7
8
9
MeV
10
11
Lightly Accelerated
3.5
3.0
2.5
2.0
1.5
1.0
0.5
C3S, 30 C, 20mmol/L CaCL 2
4500
4000
3500
Y Axis Title
3000
2500
2000
1500
1000
500
0
-500
6
7
8
9
X Axis Title
10
11
Hr
Hr
Hr
Hr
Hr
Hr
Hr
Thousand Counts
10
C3A Hydration, 10ºC
8
Min
0
5
10
20
30
40
6
4
2
0
6.50
6.75
7.00
7.25
7.50
Beam Energy, MeV
Figure 5: Hydration profiles for C3A at various times. The 0 minute sample was not
hydrated, but was treated with methanol and then stored in the vacuum with the others.
Ternary Diagram of Glass Composition
SiO2+Al2O3+Fe2O3
0
100
10
90
20
80
30
70
0.33
40
0.29
60
0.45
0.79
50
50
1.28
60
40
1.65
1.86
2.06
70
30
80
20
90
10
100
CaO
0
0
10
20
30
3.0
40
50
1.0
60
70
80
0.33
90
100
Na2O+K2O
Glass Hydration Procedure
•
•
•
•
•
Saturated Li(OH)2 Solution ( pH=12)
N2 purge to prevent carbonation
Specimens removed at 72 hours
Hydration stopped using methanol rinse
Specimens dried in 10-6 Torr vacuum
NRRA Results of FF Series
14000
Synthetic FF Fly Ash Glass Hydration, 24ºC
72 hrs, pH 12 LiOH Solution
12000
F1
F2
F3
10000
Counts
8000
6000
4000
2000
0
6.5
7.0
7.5
Beam Energy, MeV
8.0
8.5
NRRA Results of Low-Ca CF
8000
7000
Synthetic CF Fly Ash Glass Hydration, 24ºC
72 hrs, pH 12 LiOH Solution
C2
C3
C4
6000
Counts
5000
4000
3000
2000
1000
0
6.5
7.0
7.5
Beam Energy, MeV
8.0
8.5
NRRA Results of High-Ca CF
8000
7000
Synthetic CF Fly Ash Glass Hydration, 24ºC
72 hrs, pH 12 LiOH Solution
C1
C5
6000
Counts
5000
4000
3000
2000
1000
0
6.5
7.0
7.5
Beam Energy, MeV
8.0
8.5
Future Research
• Effects of Al2O3, Fe2O3 in alite
• Effect of time-varying solution chemistry
• Effects of accelerators & retarders
• Relationship between surface layers and time of
initial set
• Effects of cement storage conditions, i.e.
“dusting”
Conclusions
• NRRA is a powerful technique for understanding cement hydration
and it can determine induction period with a precision of  4
minutes or  2%
• Spatial resolution on the order of 2-3 nm can be achieved
• A surface layer is formed during the induction period for C3S but not
for C2S
• Induction period determined by mechanical breakdown of surface
layer ~ 10-20 nm thick.
• Hydration involves concentration-dependent diffusion process
• Further work is needed to determine the affects of accelerators and
especially of retarders, and to understand hydration of other cement
components