Geosynthetics June/July 2020 - 34

Enhanced moisture management of pavement systems through capillary suction

Lin and Zhang (2018)
demonstrated through
their series of triaxial
tests that the ability
to lower the moisture
content in unsaturated
materials has highly
beneficial implications
regarding increasing
the base course resilient
modulus and reducing its
permanent deformation
due to the presence of
excess moisture.

rehabilitation plan included milling the
top 3 inches (75 mm) of the pavement
and expanding the shoulder.
Eight 500-foot (152.4-m) test sections were constructed to evaluate the
performance of the ELDG, as well as two
other high-modulus woven geotextiles
and a nonwoven geotextile (Figure 11),
in controlling moisture content changes
at the subgrade level. Moisture sensors
were installed at the center of each test
section to monitor changes in moisture
content in the subgrade along the road
shoulder, where moisture contents were
expected to be more variable. These test
sections were monitored over a 20-plus
month period. Figure 12 shows that the
ELDG was very effective in minimizing
the moisture content variability over the
test period, as it had the lowest spread
of the geosynthetics included in these
tests. Reducing the difference in high
and low moisture content will reduce the
pavement damage caused by the regular
expansion and contraction of the subgrade. Delgado (2015) stated that the
ELDG test section on SH21 showed the
least shoulder cracking with none and
that results indicate the ELDG can prevent cracking in the shoulder by equilibrating moisture beneath the geotextile
through enhanced lateral drainage.

Quantification of hydraulic
benefits of ELDG to AASHTO
1993 and mechanisticempirical design guides:
University of Kansas (2018)
A series of laboratory tests, including
demonstration tests, water tank moisture removal tests, small box tests and
soil column tests, were conducted at the
University of Kansas to investigate the
hydraulic characteristics of the ELDG.
Six large-scale cyclic plate loading tests
with rainfall simulation were done to
evaluate the effect of the ELDG on the
permanent deformations of base courses
over weak subgrades. The small box tests,
the soil column tests and the large-scale
cyclic plate loading tests provided the
relationships between base course water
content and drainage time. Design guidelines that incorporate the water content
reduction benefit of the ELDG geotextile
were developed by modifying the 1993
AASHTO Pavement Design Guide and
the AASHTO Mechanistic-Empirical
Pavement Design Guide (MEPDG) (Guo
et al. 2018).
A series of rainfall simulations demonstrated that the ELDG reduced the
water content in the base course below
its optimum moisture content. Lin and
Zhang (2018) demonstrated through

FIGURE 11 Plan and section views of the test configuration on SH21

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Geosynthetics June/July 2020

Table of Contents for the Digital Edition of Geosynthetics June/July 2020

Geosynthetics June/July 2020 - Cover1
Geosynthetics June/July 2020 - Cover2
Geosynthetics June/July 2020 - 1
Geosynthetics June/July 2020 - 2
Geosynthetics June/July 2020 - 3
Geosynthetics June/July 2020 - 4
Geosynthetics June/July 2020 - 5
Geosynthetics June/July 2020 - 6
Geosynthetics June/July 2020 - 7
Geosynthetics June/July 2020 - 8
Geosynthetics June/July 2020 - 9
Geosynthetics June/July 2020 - 10
Geosynthetics June/July 2020 - 11
Geosynthetics June/July 2020 - 12
Geosynthetics June/July 2020 - 13
Geosynthetics June/July 2020 - 14
Geosynthetics June/July 2020 - 15
Geosynthetics June/July 2020 - 16
Geosynthetics June/July 2020 - 17
Geosynthetics June/July 2020 - 18
Geosynthetics June/July 2020 - 19
Geosynthetics June/July 2020 - 20
Geosynthetics June/July 2020 - 21
Geosynthetics June/July 2020 - 22
Geosynthetics June/July 2020 - 23
Geosynthetics June/July 2020 - 24
Geosynthetics June/July 2020 - 25
Geosynthetics June/July 2020 - 26
Geosynthetics June/July 2020 - 27
Geosynthetics June/July 2020 - 28
Geosynthetics June/July 2020 - 29
Geosynthetics June/July 2020 - 30
Geosynthetics June/July 2020 - 31
Geosynthetics June/July 2020 - 32
Geosynthetics June/July 2020 - 33
Geosynthetics June/July 2020 - 34
Geosynthetics June/July 2020 - 35
Geosynthetics June/July 2020 - 36
Geosynthetics June/July 2020 - 37
Geosynthetics June/July 2020 - 38
Geosynthetics June/July 2020 - 39
Geosynthetics June/July 2020 - 40
Geosynthetics June/July 2020 - 41
Geosynthetics June/July 2020 - 42
Geosynthetics June/July 2020 - 43
Geosynthetics June/July 2020 - 44
Geosynthetics June/July 2020 - 45
Geosynthetics June/July 2020 - 46
Geosynthetics June/July 2020 - 47
Geosynthetics June/July 2020 - 48
Geosynthetics June/July 2020 - Cover3
Geosynthetics June/July 2020 - Cover4
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-october-november-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-august-september-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-june-july-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-april-may-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-february-march-2021
https://www.nxtbook.com/ifai/geosynthetics/1220GS
https://www.nxtbook.com/ifai/geosynthetics/1020GS
https://www.nxtbook.com/ifai/geosynthetics/0820GS
https://www.nxtbook.com/ifai/geosynthetics/0620GS
https://www.nxtbook.com/ifai/geosynthetics/0420GS
https://www.nxtbook.com/ifai/geosynthetics/0220GS
https://www.nxtbook.com/ifai/geosynthetics/1219GS
https://www.nxtbook.com/ifai/geosynthetics/1019GS
https://www.nxtbook.com/ifai/geosynthetics/0819GS
https://www.nxtbook.com/ifai/geosynthetics/0619GS
https://www.nxtbook.com/ifai/geosynthetics/0419GS
https://www.nxtbook.com/ifai/geosynthetics/0219GS
https://www.nxtbook.com/ifai/geosynthetics/1218GS
https://www.nxtbook.com/ifai/geosynthetics/1018GS
https://www.nxtbook.com/ifai/geosynthetics/0818GS
https://www.nxtbook.com/ifai/geosynthetics/0618GS
https://www.nxtbook.com/ifai/geosynthetics/0418GS
https://www.nxtbook.com/ifai/geosynthetics/0218GS
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