3064
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
mpared. The results demons
Fig
3.5
s
and hence the degree of hydration of the GCL. Figure 7
tion of equilibrium moisture content
pore water under simulated landfill conditions was studied. The
following conclusion points could be extracted:
The hydration potential of the GCL was found to be
dependent on the difference between the suction of the GCL
small grain size and high levels of matric
the views expressed herein are
those of the authors and not necessarily those of our partner.
tic
Limit, and Plasticity Index of Soils, ASTM Standard 04.08, ASTM,
n, PA, USA: 1-13.
ni, M.T., and Rowe, K., 2012. Laboratory
Aza
Bar
Bed
Ben
Che
Gat
Tah
trated
and the subsoil. The
22, 25, 45, and 55
C were co
suction associated with clay compared to other sandy soils
was seen a limiting factor for the GCL hydration.
The thermally treated, scrim-reinforced GCL (GCL2)
demonstrated higher rate and degree of hydrati
that the rate of hydration of both GCLs was significantly
suppressed after 1 day of hydration while exposed to elevated
temperatures, as opposed to continuous moisture uptake for
months under the isothermal condition (22
C). Figure 6
demonstrates the hydration of GCL 2 and GCL3 from either
sand or clay subsoil for all the aforementioned temperatures.
The addition of 35
C heat source significantly decreased the
average equilibrium moisture content (of all experiments) by
3/4, from an average value of 96 to 24%. Also, the GCL
average equilibrium moisture content reduced from 24 to 14%
as the applied constant temperature increased from 35 to 55
C.
These results are notably similar to certain previous findings on
GCL hydration under daily thermal cycles discussed above. The
thermal gradients initiated by biodegradation of waste after
depositing the waste or solar radiation before waste placement
could induce severe loss of moisture in GCL and, hence, higher
hydraulic conductivity.
on compared to
the other GCL product under similar conditions mainly due to
the better anchorage of the connection layer against swelling
of bentonite upon hydration.
Thermal cycles severely suppressed the moisture uptake of
the GCL to as low as 15% of the moisture content observed
under isothermal conditions. Seasonal cooling was shown to
not guarantee sustainable hydration of the GCL provided that
the GCL is subsequently exposed to daily thermal cycles.
Elevated constant temperatures at the bottom of landfills
could significantly decrease the rate of hydration, the
equilibrium moisture content of the GCL, and consequently
the hydraulic performance of the GCLs
.
Employing the cover soil or the construction of leachate
collection system could provide the sufficient normal stress
(2-5 kPa) for an adequately high rate of hydration as well as
degree of hydration.
5 ACKNOWLEDGEMENTS
This research was financially supported by the Natural Science
and Engineering Research Council of Canada (NSERC). The
writers are grateful to their industrial partner Terrafix
Geosynthetics Inc., however
ure 6. GCL moisture uptake vs. temperature (Barclay & Rayhani, 2012)
External loading
The level of normal stress provided by the leachate collection
6 REFERENCES
ASTM D 2487. 2005. Standard Practice for Classification of Soils for
Engineering Purposes, ASTM, West Conshohocken, PA, USA:
249-260.
ASTM D 4318. 2005. Standard Test Method for Liquid Limit, Plas
system or the cover soil could affect the swelling characteristic
demonstrates the varia
versus the normal stress for 4 different conditions. In general,
the normal stress of 2-5 (for a typical leachate collection
system) induced the highest equilibrium moisture uptake. The
rate of moisture uptake also increased significantly as the level
of the normal stress increased. GCL2 with sand subsoil (12%
moisture content) achieved 62% gravimetric moisture content
under 8 kPa normal stress after one week of hydration which
was significantly more than that of the unconfined condition
(36%). The normal stress enhanced the contact between the
GCL and the subsoil leading to significantly higher rate of
West Conshohocke
Anderson, R., Rayha
investigation of GCL hydration from clayey sand,
Geotext. &
Geomemb.
, Vol. 31, pp 31-38.
d, F. M., Rowe, R. K., El-Zein, A., Airey, D. W., 2011. Laboratory
investigation of thermally induced desiccation of GCLs in double
composite liner systems. Geotext. & Geomemb., 29 (6), 534-543.
clay, A., and Rayhani, M.T., 2012. Effect of temperature on
hydration of Geosynthetic Clay Liners in landfills,
Journal of Waste
Management Research
, (DOI: 10.1177/0734242X12471153).
doe, R.A., Take, W.A. and Rowe, R.K., 2011. Water retention
behaviour of Geosynthetic clay liners.
ASCE J. Geotech.
Geoenviron. Eng.
, 137 (11), 1028–1038.
son, C.H., Kucukkirca, I.E., Scalia, J., 2010b. Properties of
geosynthetics exhumed from a final cover at a solid waste landfill.
Geotext. & Geomemb.
, 28 (6), 536-546.
vrier, B., Cazaux, D., Didier, G., Gamet, M., Guyonnet, D., 2012.
Influence of subgrade, temperature and confining pressure on GCL
hydration.
Geotext. &Geomemb.
, 33, 1-6.
es, W.P., Bouazza, A., 2010. Bentonite transformations in strongly
alkaline solutions.
Geotext. & Geomemb.
, 28 (2), 219-225.
Lake, C.B. Rowe, R.K., 2000. Swelling characteristics of thermally
treated GCLs.
Geotext. & Geomemb.
, 18 (2), 77-102.
Rayhani, M.T., Rowe, R.K., Brachman, R.W.I., Take, W.A., and
Siemens, G. (2011) Factors affecting GCL hydration under
isothermal conditions.
Geotext. & Geomemb.,
29, 525-533.
hydration as well as more equilibrium moisture content.
Figure 7. Effect of normal stress on the equilibrium moisture content
4 CONCLUSIONS
Rowe, R. K., 2005. Long-term performance of contaminant barrier
systems.
Geotechnique
, 55 (9), 631–678.
Sarabian, T., and Rayhani, M.T., 2012. Rate of hydration of GCLs from
clay soil.
J. of Waste Management
, 33(2013): 67-73.
The hydration of three GCL different products from the subsoil
Southen, J. M., and Rowe, R. K., 2007. Evaluation of water retention
curve for GCLs.
Geotext. & Geomemb.
, 25 (1), 2–9.
a, M., A. Interface shear behavior of sensitive marine clays-leda
clay
. M.Sc. thesis, University of Ottawa
, Ottawa, ON, Canada.
4
Fig
3.5
s
and hence the degree of hydration of the GCL. Figure 7
tion of equilibrium moisture content
pore water under simulated landfill conditions was studied. The
following conclusion points could be extracted:
The hydration potential of the GCL was found to be
dependent on the difference between the suction of the GCL
the views expressed herein are
those of the authors and not necessarily those of our partner.
tic
Limit, and Plasticity Index of Soils, ASTM Standard 04.08, ASTM,
n, PA, USA: 1-13.
ni, M.T., and Rowe, K., 2012. Laboratory
Aza
Bar
Bed
Ben
Che
Gat
Tah
demonstrated higher rate and degree of hydrati
months under the isothermal condition (22
C). Figure 6
demonstrates the hydration of GCL 2 and GCL3 from either
sand or clay subsoil for all the aforementioned temperatures.
The addition of 35
C at sourc signific ntly d creas d the
average equilibrium moisture content (of all experiments) by
3/4, from an average value of 96 to 24%. Also, the GCL
average equilibrium moisture content reduced from 24 to 14%
as the applied constant temperature increased from 35 to 55
C.
These results are notably similar to certain previous findings on
GCL hydration under d ily thermal cycles discussed above. The
thermal gradients initiated by biodegradation of waste aft r
depositing the waste or solar radiation before waste placement
could ind ce severe loss of oisture in GCL and, hence, higher
hydraulic conductivity.
on compared to
the other GCL product under similar conditions mainly due to
the better anchorage of the connection layer against swelling
of bentonite upon hydration.
Thermal cycles severely suppressed the moisture uptake of
the GCL to as low as 15% of the moisture content observed
under isothermal conditions. Seasonal cooling was shown to
not guarantee sustainable hydration of the GCL provided that
the GCL is subsequ ntly exposed to d ily thermal cycles.
Elevated constant temperatures at the bottom of landfills
could significantly decrease the rate of hydration, the
equilibrium oisture content of the GCL, and consequently
the hydraulic performance of the GCLs
.
Employing the cover soil or the construction of leachate
collection system could provide the sufficient normal stress
(2-5 kPa) for an adequately high rate of hydration as well as
degree of hydration.
5 ACKNOWLEDGEMENTS
This research was financially supported by the Natural Science
and Engineering Research Council of Canada (NSERC). The
writers are grateful to their industrial partner Terrafix
Geosynthetics Inc., however
ure 6. GCL moisture uptake vs. temperature (Barclay & Rayhani, 2012)
External loading
The level of normal stress provided by the leachate collection
6 REFERENCES
ASTM D 2487. 2005. Standard Practice for Classification of Soils for
Engineering Purposes, ASTM, West Conshohocken, PA, USA:
249-260.
ASTM D 4318. 2005. Standard Test Method for Liquid Limit, Plas
system or the cover soil could affect the swelling characteristic
demonstrates the varia
versus the normal stress for 4 different conditions. In general,
the normal stress of 2-5 (for a typical leachate collection
system) induced the highest equilibrium moisture uptake. The
rate of moisture uptake also increased significantly as the level
of the normal stress increased. GCL2 with sand subsoil (12%
moisture content) achieved 62% gravimetric moisture content
under 8 kPa normal stress after one week of hydration which
was significantly more than that of the unconfined condition
(36%). The normal stress enhanced the contact between the
GCL and the subsoil leading to significantly higher rate of
West Conshohocke
Anderson, R., Rayha
investigation of GCL hydration from clayey sand,
Geotext. &
Geomemb.
, Vol. 31, pp 31-38.
d, F. M., Rowe, R. K., El-Zein, A., Airey, D. W., 2011. Laboratory
investigation of thermally induced desiccation of GCLs in double
composite liner systems. Geotext. & Geomemb., 29 (6), 534-543.
clay, A., and Rayhani, M.T., 2012. Effect of temperature on
hydration of Geosynthetic Clay Liners in landfills,
Journal of Waste
Management Research
, (DOI: 10.1177/0734242X12471153).
doe, R.A., Take, W.A. and Rowe, R.K., 2011. Water retention
behaviour of Geosynthetic clay liners.
ASCE J. Geotech.
Geoenviron. Eng.
, 137 (11), 1028–1038.
son, C.H., Kucukkirca, I.E., Scalia, J., 2010b. Properties of
geosynthetics exhumed from a final cover at a solid waste landfill.
Geotext. & Geomemb.
, 28 (6), 536-546.
vrier, B., Cazaux, D., Didier, G., Gamet, M., Guyonnet, D., 2012.
Influence of subgrade, temperature and confining pressure on GCL
hydration.
Geotext. &Geomemb.
, 33, 1-6.
es, W.P., Bouazza, A., 2010. Bentonite transformations in strongly
alkaline solutions.
Geotext. & Geomemb.
, 28 (2), 219-225.
Lake, C.B. Rowe, R.K., 2000. Swelling characteristics of thermally
treated GCLs.
Geotext. & Geomemb.
, 18 (2), 77-102.
Rayhani, M.T., Rowe, R.K., Brachman, R.W.I., Take, W.A., and
Siemens, G. (2011) Factors affecting GCL hydration under
isothermal conditions.
Geotext. & Geomemb.,
29, 525-533.
hydration as well as more equilibrium moisture content.
Figure 7. Effect of normal stress on the equilibrium moisture content
4 CONCLUSIONS
Rowe, R. K., 2005. Long-term performance of contaminant barrier
systems.
Geotechnique
, 55 (9), 631–678.
Sarabian, T., and Rayhani, M.T., 2012. Rate of hydration of GCLs from
clay soil.
J. of Waste Management
, 33(2013): 67-73.
The hydration of three GCL different products from the subsoil
Southen, J. M., and Rowe, R. K., 2007. Evaluation of water retention
curve for GCLs.
Geotext. & Geomemb.
, 25 (1), 2–9.
a, M., A. Interface shear behavior of sensitive marine clays-leda
clay
. M.Sc. thesis, University of Ottawa
, Ottawa, ON, Canada.
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
mpared. The results demons
Fig
3.5
s
and hence t degree of hydration of the GCL. Figure 7
tion of equilibrium moisture content
pore water under simulated landfill conditions was studied. The
following conclusion points could be extracted:
The hydration potential of the GCL was found to be
dependent on the difference between the suction of the GCL
small grain siz and hig levels of matric
the views expressed herein are
thos of the authors and not necessar ly h se of our partner.
tic
Limit, and Plasticity Index of Soils, ASTM Standard 04.08, ASTM,
n, PA, USA: 1-13.
ni, M.T., and Rowe, K., 2012. Laboratory
Aza
Bar
Bed
Ben
Che
Gat
Tah
trated
and the subsoil. The
22, 25, 45, and 55
C were co
suctio associated with clay compare to other sandy soils
was seen a limiting factor for the GCL hydration.
The thermally treated, scrim-reinfo ced GCL (GCL2)
demonstrated higher rate and degree of hydrati
that the rat of h dration of both GCLs was significantly
suppress d after 1 day of hydration while exposed to elevated
temperatur s, as oppos d to continu us moisture uptake for
months under the is thermal condition (22
C). Figur 6
demonstrate the hyd ation of GCL 2 and GCL3 from either
sand or clay subsoil for all the aforementione temp ratures.
The addition of 35
C heat s urce significantly decrea ed the
average equilibrium moisture content (of all experiments) by
3/4, from an average value of 96 to 24%. Also, the GCL
av rage equilibrium moistu e content reduced from 24 to 14%
as the applied constant te peratur increas d from 35 to 55
C.
These results are notabl similar to ertain previous findings on
GCL hydration under daily thermal cycles discussed above. The
thermal gradients initiated by bi degradation of waste after
depositing the waste or solar radiation before waste placement
could induce ev re loss of oistur in GCL and, ence, higher
hydraulic conductivity.
on compared to
the other GCL product under similar conditions mainly due to
th better anchorage of the connection layer against swelling
of bentonite upon hydration.
Thermal cycles severely suppressed th moisture uptake of
th GCL to as low as 15% of the moisture content bserved
under isothermal conditions. Seas nal cooling was shown to
not guarantee sustain ble hydration of the GCL provid d that
th GCL s subsequ ntly exposed to d ily ther al cycles.
Elevated o stant temperatur s at the bottom of landfills
could significantly d crease the rate of hydration, the
quilibrium moisture content of the GCL, and co sequently
the hydraulic perf rmance of the GCLs
.
Employing the cover soil or the construction of leachate
collection system could provide the sufficient normal stress
(2-5 kPa) for an adequately high rate of hydration as well as
degree of hydration.
5 ACKNOWLEDGEMENTS
This res arch was financially supp rted by the Natural Science
and Engineering Research Council of Canada (NSERC). The
writers are grateful to t eir industrial partner Terrafix
G osynthetics Inc., however
ure 6. GCL moisture uptake vs. temperature (Barclay & Rayhani, 2012)
External loading
The level of normal stress provided by the leac ate collection
6 REFERENCES
ASTM D 2487. 2005. Standard Practice for Classification of Soils for
Engineering Purposes, ASTM, West Conshohocken, PA, USA:
249-260.
ASTM D 4318. 2005. Standard Test Method for Liquid Limit, Plas
syst m or t cover soil coul ffect the swelling characteristic
demonstrates the varia
versus the normal stress for 4 different conditions. In general,
th normal stress of 2-5 (for a typical leachate collection
syste ) induced the highest equilibrium moisture uptak . The
rat of oisture uptake lso increased significantly as the level
f the n rmal stress increased. GCL2 with sand subsoil (12%
moisture content) achieved 62% gravimetric moisture content
under 8 kPa nor al stress after one week of hy ration which
was significantly more than that of the u confined condition
(36%). The normal stress enhanced the contact betwe n the
GCL and the subs il leading to significantly higher rate of
West Conshohocke
Anderson, R., Rayha
investigation of GCL hydration from clayey sand,
Geotext. &
Geomemb.
, Vol. 31, pp 31-38.
d, F. M., Rowe, R. K., El-Zein, A., Airey, D. W., 2011. Laboratory
investigation of thermally induced desiccation of GCLs in double
composite liner systems. Geotext. & Geomemb., 29 (6), 534-543.
clay, A., and Rayhani, M.T., 2012. Effect of temperature on
hydration of Geosynthetic Clay Li ers in landfills,
Journal of Waste
Ma agement Research
, (DOI: 10.1177/0734242X12471153).
doe, R.A., Take, W.A. and Rowe, R.K., 2011. Water retention
behaviour of Geosynthetic clay liners.
ASCE J. Geotech.
Geoenvir n. E g.
, 137 (11), 1028–1038.
son, C.H., Kucukkirca, I.E., Scalia, J., 2010b. Properties of
geosynthetics exhumed from a final cover at a solid waste landfill.
Geotext. & Geomemb.
, 28 (6), 536-546.
vrier, B., Cazaux, D., Didier, G., Gamet, M., Guyonnet, D., 2012.
Influence of subgrade, temperature and confining pressure on GCL
hydration.
Geotext. &Geomemb.
, 33, 1-6.
es, W.P., Bouazza, A., 2010. Bentonite transformations in strongly
alkaline solutions.
Geotext. & Geomemb.
, 28 (2), 219-225.
Lake, C.B. Rowe, R.K., 2000. Swelling characteristics of thermally
treated GCLs.
Geotext. & Geomemb.
, 18 (2), 77-102.
Rayhani, M.T., Rowe, R.K., Brachman, R.W.I., Take, W.A., and
Siemens, G. (2011) Factors affecting GCL hydration under
isothermal conditions.
Geotext. & Geomemb.,
29, 525-533.
hydration as well as more equilibrium moisture content.
Figure 7. Effect of normal stress on the equilibrium moisture content
4 CONCLUSIONS
Rowe, R. K., 2005. Long-term performance of contaminant barrier
systems.
Geotechnique
, 55 (9), 631–678.
Sarabian, T., and Rayhani, M.T., 2012. Rate of hydration of GCLs from
clay soil.
J. of Waste Management
, 33(2013): 67-73.
The hydration of three GCL different products from the subsoil
Southen, J. M., and Rowe, R. K., 2007. Evaluation of water retention
curve for GCLs.
Geotext. & Geomemb.
, 25 (1), 2–9.
a, M., A. Interface shear behavior of sensitive marine clays-leda
clay
. M.Sc. thesis, University of Ottawa
, Ottawa, ON, Canada.
