Working Report 2012-14
Laboratory Measurements of
the Coefficient of Thermal Expansion of
Olkiluoto Drill Core Samples
Urban Åkesson
April 2012
POSIVA OY
FI-27160 OLKILUOTO, FINLAND
Tel +358-2-8372 31
Fax +358-2-8372 3709
Working Report 2012-14
Laboratory Measurements of
the Coefficient of Thermal Expansion of
Olkiluoto Drill Core Samples
Urban Åkesson
Swedish Cement and Concrete Research Institute
April 2012
Working Reports contain information on work in progress
or pending completion.
Laboratory Measurements of the Coefficient of Thermal Expansion of
Olkiluoto Drill Core Samples
ABSTRACT
The coefficient of thermal expansion and the wet density has been determined on 22
specimens from the ONKALO drillholes ONK-PP167, ONK-PP199, ONK-PP224,
ONK-PP225 and ONK-PP226, Olkiluoto, Finland.
The coefficient of thermal expansion has been determined in the temperature interval
20-60 ºC. The results indicated that the thermal expansion was almost linear, and the
coefficient of thermal expansion for the investigated specimens range between 3.2 and
14.4 x 10-6 mm/mm ÛC, and the wet density between 2,610 and 2,820 kg/m3. The
granite pegmatite has slightly lower coefficient of thermal expansion and wet density
than gneissic rocks.
Keywords: Coefficient of thermal expansion, Olkiluoto, laboratory measurements, rock
core samples, wet density.
Kiven lämpölaajenemiskertoimen laboratoriomääritykset Olkiluodon
kairasydännäytteistä
TIIVISTELMÄ
Kiven lämpölaajenemiskerroin ja märkätiheys on määritetty Olkiluodon 22
kairasydännäytteistä. Näytteet ovat ONKALOn tutkimusrei’istä ONK-PP167, ONKPP199, ONK-PP224, ONK-PP225 ja ONK-PP226.
Lämpölaajenemiskerroin on määritetty lämpötilaväliltä 20 - 60 °C. Tulokset kertovat,
että lämpölaajeneminen on lähes lineaarista ja lämpölaajenemiskerroin tutkituilla
näytteillä vaihtelee välillä 3,2 – 14,4 x 10-6 mm/mm ÛC ja märkätiheys välillä 2610 2820 kg/m3. Pegmatiitti-graniiteilla on hieman alhaisempi lämpölaajenemiskerroin ja
märkätiheys kuin gneisseillä.
Avainsanat: Lämpölaajenemiskerroin, Olkiluoto, laboratoriomittaus, kairasydännäyte,
märkätiheys
1
TABLE OF CONTENTS
ABSTRACT
TIIVISTELMÄ
1
INTRODUCTION ................................................................................................... 2
2
EQUIPMENT ......................................................................................................... 3
3
EXECUTION ......................................................................................................... 4
3.1 Description of the specimens ....................................................................... 4
3.2 Testing ......................................................................................................... 5
4
RESULTS .............................................................................................................. 6
4.1 Description of the specimens and presentation of the results ...................... 6
4.2 Summary of results .................................................................................... 29
REFERENCES ............................................................................................................. 31
2
1
INTRODUCTION
The purpose of this report was to determine the coefficient of thermal expansion and the
wet density of intact rock cores from the Olkiluoto drillcore samples.
The testing comprised of 22 rock specimens from the ONKALO drillholes ONKPP167, ONK-PP199, ONK-PP224, ONK-PP225 and ONK-PP226. The locations of the
drillholes are shown in Figure 1-1.
The specimens were sampled by Posiva Oy, and sent to the Swedish Cement and
Concrete Research Institute in Borås, Sweden who performed the test. Testing
commenced in April 2010 and was completed in May 2010.
ONK-PP167
ONK-PP199
ONK-PP224
ONK-PP225
ONK-PP226
-290 m
-437 m
Figure 1-1. The locations of the ONKALO drillholes for determination of thermal
expansion coefficients.
3
2
EQUIPMENT
The following equipment has been used for the laboratory measurements:
x
Extensometer (DEMEC inv no 102266) for measurement of the thermal
expansion. The uncertainty of the extensometer is ± 3.97 x 10-6 mm/mm (strain),
which equals an uncertainty of a single measurement of the coefficient of
thermal expansion of ± 0.2 x 10-6 mm/mm oC for a temperature difference of 20
degrees C.
x
Reference bar in invar steel for calibrate the extensometer.
x
Heating chamber (inv no 102284) with an accuracy of ± 0.7 ºC at 80 ºC for
heating up the specimens.
x
A covered plastic box filled with water for keeping the specimens water
saturated.
The equipment was same as used for SKB’s thermal expansion property measurements
at Oskarshamn and Forsmark sites (see e.g. Åkesson 2007).
4
3
EXECUTION
Determination of the coefficient of thermal expansion was made in accordance with
SKB’s method description SKB MD 191.002-version 2.0 (SKB internal controlling
document). The Swedish Cement and Concrete Research Institute performed the tests.
3.1
Description of the specimens
The specimens from the drillholes ONK-PP167, ONK-PP199, ONK-PP224, ONKPP225 and ONK-PP226 were sampled on various depths in the drillholes. Table 3-1
shows the identification mark, sampling level and rock type description of each
specimen.
Table 3-1. Identification mark, drillhole ID, sampling position and rock type of each
specimen. Rock type abbreviations: VGN is veined gneiss, DGN is diatexitic gneiss and
PGR pegmatitic granite. The veined gneisses are divided in two groups by the foliation
angle; parallel (foliation 0) and perpendicular (foliation 90) to the core axis.
Sample ID
Drillhole ID
Drillhole depth (m)
Rock type code
3784
ONK-PP167
1.95-2.49
VGN (foliation 90)
3785
ONK-PP167
4.42-4.98
VGN (foliation 90)
3786
ONK-PP199
10.33-10.75
PGR
3787
ONK-PP199
47.45-48.03
PGR
3788
ONK-PP224
1.93-2.46
DGN
3789
ONK-PP224
3.64-4.15
DGN
3790
ONK-PP224
5.00-5.48
DGN
3791
ONK-PP224
7.42-8.07
PGR
3792
ONK-PP224
9.24-9.85
PGR
3793
ONK-PP224
13.39-13.75
VGN (foliation 0)
3794
ONK-PP224
16.75-17.3
VGN (foliation 0)
3795
ONK-PP224
27.97-28.50
VGN (foliation 0)
3796
ONK-PP225
0.83-1.46
DGN
3797
ONK-PP225
3.54-4.05
DGN
3798
ONK-PP225
4.70-5.26
DGN
3799
ONK-PP225
9.62-10.22
PGR
3800
ONK-PP225
19.26-19.72
VGN (foliation 0)
3801
ONK-PP225
19.72-20.18
VGN (foliation 0)
3802
ONK-PP225
29.00-29.56
PGR
3803
ONK-PP226
2.93-3.50
VGN (foliation 90)
3804
ONK-PP226
20.56-21.03
VGN (foliation 90)
3805
ONK-PP226
23.45-23.88
VGN (foliation 90)
5
3.2
Testing
The execution procedure followed the prescription in SKB MD 191.002 and the
following steps were performed:
Item
1
2
3
4
5
6
Activity
The specimens were cut according to the marks on the rock cores.
Two measuring points with a distance of 200 mm were glued on the specimens.
The specimens were photographed in JPEG format.
The specimens were water saturated for seven days.
The wet density was determined.
The coefficient of thermal expansion was determined. The thermal expansion
measured at 20, 40 and 60 ºC. On each temperature level was three to
measurements done with 24 h intervals in order to know that the expansion
completed for each temperature level. The coefficient of thermal expansion
determined between 20-60 ºC.
was
five
was
was
6
4
RESULTS
The results of the coefficient of thermal expansion and wet density determinations of
core samples from the drillholes ONK-PP167, ONK-PP199, ONK-PP224, ONK-PP225
and ONK-PP226 are presented here. The temperature of the water used for the water
saturation was 21.5 ºC and the density of the water was 997 kg/m3. The coefficient of
thermal expansion was determined between +20- +60 ºC to cover the rock temperature
range equivalent to the disposal process.
4.1
Description of the specimens and presentation of the results
Specimen 3784
Thermalexpansion(mm/mm)
3784
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-1. Diagram showing the thermal expansion of specimen 3784 between 20 and 60 ºC,
mean values plotted.
Figure 4-1 shows a picture of the specimen 3784 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3784 was measured to be 13.2 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,780 kg/m3.
7
Specimen 3785
Thermalexpansion(mm/mm)
3785
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-2. Diagram showing the thermal expansion of specimen 3785 between 20 and 60 ºC,
mean values plotted.
Figure 4-2 shows a picture of the specimen 3785 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3785 was measured to be 8.4 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,720 kg/m3.
8
Specimen 3786
Thermalexpansion(mm/mm)
3786
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-3. Diagram showing the thermal expansion of specimen 3786 between 20 and 60 ºC,
mean values plotted.
Figure 4-3 shows a picture of the specimen 3786 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3786 was measured to be 3.2 x 10-6 mm/mmº C and the specimen had a wet
density of 2,610 kg/m3. Clear non-linear behaviour was noticed in the results.
9
Specimen 3787
Thermalexpansionmm/mm
3787
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-4. Diagram showing the thermal expansion of specimen 3787 between 20 and 60 ºC,
mean values plotted.
Figure 4-4 shows a picture of the specimen 3787 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3787 was measured to be 7.8 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,650 kg/m3.
10
Specimen 3788
Thermalexpansionmm/mm
3788
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-5. Diagram showing the thermal expansion of specimen 3788 between 20 and 60 ºC,
mean values plotted.
Figure 4-5 shows a picture of the specimen 3788 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3788 was measured to be 8.3 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,690 kg/m3.
11
Specimen 3789
Thermalexpansionmm/mm
3789
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-6. Diagram showing the thermal expansion of specimen 3789 between 20 and 60 ºC,
mean values plotted.
Figure 4-6 shows a picture of the specimen 3789 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3789 was measured to be 8.7 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,720 kg/m3.
12
Specimen 3790
Thermalexpansionmm/mm
3790
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-7. Diagram showing the thermal expansion of specimen 3790 between 20 and 60 ºC,
mean values plotted.
Figure 4-7 shows a picture of the specimen 3790 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3790 was measured to be 8.6 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,710 kg/m3.
13
Specimen 3791
Thermalexpansionmm/mm
3791
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-8. Diagram showing the thermal expansion of specimen 3791 between 20 and 60 ºC,
mean values plotted.
Figure 4-8 shows a picture of the specimen 3791 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3791 was measured to be 8.3 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,640 kg/m3.
14
Specimen 3792
Thermalexpansionmm/mm
3792
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-9. Diagram showing the thermal expansion of specimen 3792 between 20 and 60 ºC,
mean values plotted.
Figure 4-9 shows a picture of the specimen 3792 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3792 was measured to be 10.8 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,630 kg/m3. Minor non-linear behaviour was noticed in the results.
15
Specimen 3793
Thermalexpansionmm/mm
3793
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-10. Diagram showing the thermal expansion of specimen 3793 between 20 and 60 ºC,
mean values plotted.
Figure 4-10 shows a picture of the specimen 3793 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3793 was measured to be 10.8 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,750 kg/m3. Minor non-linear behaviour was noticed in the results.
16
Specimen 3794
Thermalexpansionmm/mm
3794
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-11. Diagram showing the thermal expansion of specimen 3794 between 20 and 60 ºC,
mean values plotted.
Figure 4-11 shows a picture of the specimen 3794 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3794 was measured to be 14.4 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,790 kg/m3. Minor non-linear behaviour was noticed in the results.
17
Specimen 3795
Thermalexpansionmm/mm
3795
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-12. Diagram showing the thermal expansion of specimen 3795 between 20 and 60 ºC,
mean values plotted.
Figure 4-12 shows a picture of the specimen 3795 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3795 was measured to be 11.0 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,820 kg/m3.
18
Specimen 3796
Thermalexpansionmm/mm
3796
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-13. Diagram showing the thermal expansion of specimen 3796 between 20 and 60 ºC,
mean values plotted.
Figure 4-13 shows a picture of the specimen 3796 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3796 was measured to be 8.6 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,740 kg/m3.
19
Specimen 3797
Thermalexpansionmm/mm
3797
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-14. Diagram showing the thermal expansion of specimen 3797 between 20 and 60 ºC,
mean values plotted.
Figure 4-14 shows a picture of the specimen 3797 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3797 was measured to be 8.5 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,750 kg/m3.
20
Specimen 3798
Thermalexpansionmm/mm
3798
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-15. Diagram showing the thermal expansion of specimen 3798 between 20 and 60 ºC,
mean values plotted.
Figure 4-15 shows a picture of the specimen 3798 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3798 was measured to be 6.8 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,750 kg/m3.
21
Specimen 3799
Thermalexpansionmm/mm
3799
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-16. Diagram showing the thermal expansion of specimen 3799 between 20 and 60 ºC,
mean values plotted.
Figure 4-16 shows a picture of the specimen 3799 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3799 was measured to be 8.7 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,630 kg/m3.
22
Specimen 3800
Thermalexpansionmm/mm
3800
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-17. Diagram showing the thermal expansion of specimen 3800 between 20 and 60 ºC,
mean values plotted.
Figure 4-17 shows a picture of the specimen 3800 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3800 was measured to be 8.5 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,710 kg/m3.
23
Thermalexpansionmm/mm
Specimen 3801
3801
0,00035
0,0003
0,00025
0,0002
0,00015
0,0001
0,00005
0
20
40
60
TemperatureC
Figure 4-18. Diagram showing the thermal expansion of specimen 3801 between 20 and 60 ºC,
mean values plotted.
Figure 4-18 shows a picture of the specimen 3801 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3801 was measured to be 7.1 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,740 kg/m3.
24
Specimen 3802
Thermalexpansionmm/mm
3802
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-19. Diagram showing the thermal expansion of specimen 3802 between 20 and 60 ºC,
mean values plotted.
Figure 4-19 shows a picture of the specimen 3802 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3802 was measured to be 4.6 x 10-6 mm/mmº C and the specimen had a wet
density of 2,620 kg/m3. Non-linear behaviour was noticed in the results.
25
Specimen 3803
Thermalexpansionmm/mm
3803
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-20. Diagram showing the thermal expansion of specimen 3803 between 20 and 60 ºC,
mean values plotted.
Figure 4-20 shows a picture of the specimen 3803 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3803 was measured to be 12.3 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,740 kg/m3. Non-linear behaviour was noticed in the results.
26
Specimen 3804
Thermalexpansionmm/mm
3804
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-21. Diagram showing the thermal expansion of specimen 3804 between 20 and 60 ºC,
mean values plotted.
Figure 4-21 shows a picture of the specimen 3804 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3804 was measured to be 9.5 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,750 kg/m3.
27
Specimen 3805
Thermalexpansionmm/mm
3805
0,0006
0,0005
0,0004
0,0003
0,0002
0,0001
0
20
40
60
TemperatureC
Figure 4-22. Diagram showing the thermal expansion of specimen 3805 between 20 and 60 ºC,
mean values plotted.
Figure 4-22 shows a picture of the specimen 3805 and a diagram for the thermal
expansion in the interval 20, 40 and 60 ºC. The coefficient of thermal expansion for
specimen 3804 was measured to be 10.6 x 10-6 mm/mm ºC and the specimen had a wet
density of 2,760 kg/m3. Minor non-linear behaviour was noticed in the results.
28
In order to investigate the non-linearity the specimen 3802 was remeasured. This time
additional measuring points were glued on the specimen approximately at 120 degrees
angles (see Figure 4-23).
Figure 4-23. Photograph showing how the measuring points were placed on specimen
3802.
The results of the measurements are shown in Figure 4-24, which indicates that the nonlinear phenomenon is partly due to bending of the drill core. The coefficients of thermal
expansion for the measuring points were: 3802:1 5.0 x 10-6, 3802:2 4.8 x 10-6 and
3802:3 8.0 x 10-6 mm/mm ºC.
3802
0,0006
Thermalexpansionmm/mm
0,0005
0,0004
3802;1
0,0003
3802;2
0,0002
3802;3
0,0001
1,8EͲ18
20
40
60
Ͳ1EͲ04
Figure 4-24. Diagram showing the thermal expansion of specimen 3802 between 20
and 60 ºC, measured from three different sides of the specimen. Mean values are
plotted.
29
4.2
Summary of results
All the results are shown in Table 4-1 and Figure 4-25. Range of the coefficient of
thermal expansion of all specimens is between 3.2 – 14.4 x 10-6 mm/mm qC with mean
value being 9.0 x 10-6 mm/mm qC. Pegmatitic granite (range 3.2 – 10.8 x 10-6 with
mean value of 7.2 x 10-6 mm/mm qC) has slightly lower values than gneissic rocks
(range 7.1 – 14.4 x 10-6 with mean value of 9.7 mm/mm qC) (Figure 4-25).
The foliation does not seem to affect the expansion properties, since the mean values are
practically the same; VGN perpendicular foliation 10.8 x 10-6 mm/mm qC vs. VGN
parallel foliation 10.4 x 10-6 mm/mm qC.
The results are also in good agreement with the results presented in Huotari &
Kukkonen (2004). They concluded that the linear thermal expansion coefficient of the
Olkiluoto gneiss is 7-10 (10-6/°C) in the temperatures between 20-60 °C and this study
states the value for gneissic rocks are 7-14 (10-6/°C).
Table 4-1. Summary of the results for the coefficient of thermal expansion (mean
values) and wet density of the tested specimens. Rock type abbreviations: VGN is veined
gneiss, DGN is diatexitic gneiss and PGR pegmatitic granite. The veined gneisses are
divided in two groups by the foliation angle; parallel (foliation 0) and perpendicular
(foliation 90) to core axis.
Drillhole ID
Specimen
Rock type code
ONK-PP167
ONK-PP167
ONK-PP199
ONK-PP199
ONK-PP224
ONK-PP224
ONK-PP224
ONK-PP224
ONK-PP224
ONK-PP224
ONK-PP224
ONK-PP224
ONK-PP225
ONK-PP225
ONK-PP225
ONK-PP225
ONK-PP225
ONK-PP225
ONK-PP225
ONK-PP226
ONK-PP226
ONK-PP226
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
VGN (foliation 90)
VGN (foliation 90)
PGR
PGR
DGN
DGN
DGN
PGR
PGR
VGN (foliation 0)
VGN (foliation 0)
VGN (foliation 0)
DGN
DGN
DGN
PGR
VGN (foliation 0)
VGN (foliation 0)
PGR
VGN (foliation 90)
VGN (foliation 90)
VGN (foliation 90)
Coefficient of
thermal expansion
between 20 and
60 ºC (mm/mmºC)
13.2 x 10-6
8.4 x 10-6
3.2 x 10-6
7.8 x 10-6
8.3 x 10-6
8.7 x 10-6
8.6 x 10-6
8.3 x 10-6
10.8 x 10-6
10.8 x 10-6
14.4 x 10-6
11.0 x 10-6
8.6 x 10-6
8.5 x 10-6
6.8 x 10-6
8.7 x 10-6
8.5 x 10-6
7.1 x 10-6
4.6 x 10-6
12.3 x 10-6
9.5 x 10-6
10.6 x 10-6
Wet density
(kg/m3)
2,780
2,720
2,610
2,650
2,690
2,720
2,710
2,640
2,630
2,750
2,790
2,820
2,740
2,750
2,750
2,630
2,710
2,740
2,620
2,740
2,750
2,760
30
The wet density of gneissic rocks 2,745 kg/m3 (mean value) is higher than for pegmatitic
granite 2,630 kg/m3 (mean value).
2,850
2,800
Wetdensity(kg/m3)
VGNfol90°
PGR
2,750
DGN
VGNfol0°
2,700
2,650
2,600
2,550
0,00E+00
2,00EͲ06
4,00EͲ06
6,00EͲ06
8,00EͲ06
1,00EͲ05
1,20EͲ05
1,40EͲ05
1,60EͲ05
Coefficientofthermalexpansionbetween20and60qC(mm/mmqC)
Figure 4-25. The results for the coefficient of thermal expansion (mean values) and wet
density of the tested specimens.
31
REFERENCES
Huotari, T. & Kukkonen I. 2004. Thermal expansion properties of rocks: Literature
survey and estimation of thermal expansion coefficient for Olkiluoto mica gneiss.
Posiva Oy, Working Report 2004-04.
Åkesson, U. 2007. Forsmark site investigation, Boreholes KFM05A and KFM06A,
Extensometer measurement of the coefficient of thermal expansion of rock. SKB Report
P-07-33.