ASTM D6088-06(2022)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6088 − 06 (Reapproved 2022)
Standard Practice for
Installation of Geocomposite Pavement Drains
This standard is issued under the fixed designation D6088; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice covers recommendations and identifies
ization established in the Decision on Principles for the
pertinent areas of consideration for the installation of buried
Development of International Standards, Guides and Recom-
geocomposite drains used for highway edgedrains, under-
mendations issued by the World Trade Organization Technical
drains, or other pavement drainage applications meeting the
Barriers to Trade (TBT) Committee.
requirements of Specification D7001. These recommendations
are intended as guidelines for developing a satisfactory con-
2. Referenced Documents
struction and installation method to minimize installation-
2.1 ASTM Standards:
caused deformation or damage and to provide long-term
D8 Terminology Relating to Materials for Roads and Pave-
performanceoftheseproducts.Itisalsointendedasaguideline
ments
for ensuring a stable underground environment for these
D420 Guide for Site Characterization for Engineering De-
materials under a wide range of service conditions. Because of
sign and Construction Purposes
the numerous and diverse product designs available and the
D653 Terminology Relating to Soil, Rock, and Contained
inherent variability of natural ground conditions, achieving
Fluids
satisfactory performance of any one product may require
D698 Test Methods for Laboratory Compaction Character-
review by the engineer and modification to provisions con-
istics of Soil Using Standard Effort (12,400 ft-lbf/ft (600
tained herein to meet specific project requirements.
kN-m/m ))
1.2 The scope of this practice necessarily excludes product
D2321 PracticeforUndergroundInstallationofThermoplas-
performance criteria such as compressibility in any plane, flow
tic Pipe for Sewers and Other Gravity-Flow Applications
capacity, inlet capacity, or geotextile selection and use. It is,
D2487 Practice for Classification of Soils for Engineering
therefore, incumbent upon the product manufacturer, specifier,
Purposes (Unified Soil Classification System)
and project engineer to verify that the product specified for an
D3839 Guide for Underground Installation of “Fiberglass”
intended application, when installed according to procedures
(Glass-Fiber Reinforced Thermosetting-Resin) Pipe
outlined in this practice, will provide satisfactory long-term
D4318 Test Methods for Liquid Limit, Plastic Limit, and
performance according to criteria established by the owner for
Plasticity Index of Soils
that application. A commentary of product performance and
D4439 Terminology for Geosynthetics
installation factors important in achieving a satisfactory instal-
D7001 Specification for Geocomposites for Pavement Edge
lation is included in Appendix X1.
Drains and Other High-Flow Applications
1.3 The values stated in SI units are to be regarded as the
F412 Terminology Relating to Plastic Piping Systems
standard. The inch-pound units given in parentheses are for
3. Terminology
information only.
1.4 This standard does not purport to address all of the 3.1 Definitions:
safety concerns, if any, associated with its use. It is the 3.1.1 Definitionsusedinthispracticeareinaccordancewith
responsibility of the user of this standard to establish appro- Terminologies F412, D8, and D653 unless otherwise indicated.
priate safety, health, and environmental practices and deter- 3.2 Definitions:
mine the applicability of regulatory limitations prior to use. 3.2.1 aggregate—a granular material of mineral composi-
tion such as sand, gravel, shell, slag or crushed stone (see
Terminology D8).
This practice is under the jurisdiction of ASTM Committee D35 on Geosyn-
thetics and is the direct responsibility of Subcommittee D35.03 on Permeability and
Filtration. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2022. Published May 2022. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1997. Last previous edition approved in 2016 as D6088 – 06 (2016). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D6088-06R22. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6088 − 06 (2022)
3.2.2 dense-graded aggregate—an aggregate that has a 5. Significance and Use
particle size distribution such that, when it is compacted, the
5.1 Thispracticeisintendedtoprovideinstallationguidance
resulting voids between the aggregate particles, expressed as a
for designers, specifiers, installation contractors, regulatory
percentage of the total space occupied by the material, are
agencies, owners, and inspectors who are involved in the
relatively small.
planning and installation of geocomposite pavement edge-
3.2.3 engineer—the individual in responsible charge of the
drains and underdrains. As with any standard practice, modi-
work or his duly recognized or authorized representative.
fication may be required for specific project conditions or for
special local or regional conditions. Fig. 1 shows the proper
3.2.4 geocomposite, n—a product fabricated from any com-
horizontal alignment of the drain based on various trench
bination of geosynthetics with geotechnical materials or other
conditions outlined in 9.2, and the vertical depth of placement
synthetics which is used in a geotechnical application.
of the drain needed for a geocomposite edge drain to function
3.2.5 geosynthetic, n—a planar product manufactured from
most effectively as both a collector and conduit.
polymeric material used with foundation, soil, rock, earth, or
5.2 Fig. 2 shows the typical type and arrangement of
any other geotechnical engineering related material as an
equipment used to install geocomposite highway edgedrains.
integral part of a man-made project, structure, or system. (See
The combination of these recommended installation
Terminology D4439.)
conditions, techniques, and equipment are critical to the
3.2.6 geotextile, n—any permeable geosynthetic comprised
satisfactory long-term performance of these products.
solely of textiles. (See Terminology D4439.)
3.2.7 manufactured aggregates—aggregates such as slag
6. Inspection, Handling, and Storage
that are products or byproducts of a manufacturing process, or
6.1 Inspection—Upon receipt, inspect each shipment of
natural aggregates that are reduced to their final form by a
pipe, geocomposite, and fittings for conformance to product
manufacturing process such as crushing.
specifications and contract documents, and check for damage.
3.2.8 open-graded aggregate—an aggregate that has a par-
The engineer should reject damaged, deformed, crushed, or
ticlesizedistributionsuchthat,whenitiscompacted,thevoids
nonconforming material and remove from the project.
between the aggregate particles, expressed as a percentage of
6.2 Handling and Storage—Handleandstorethematerialin
the total space occupied by the material, remain relatively
such a way as to prevent damage. Protect all geotextile
large.
materials from sunlight exposure until immediately before
3.2.9 optimum moisture content—The moisture content of
installation.
soil at which its maximum density is obtained (see Test
Methods D698).
7. Backfill Materials
3.2.10 permeability, n—the rate of flow of a liquid under a
7.1 Backfill material selection and placement method
differential pressure through a material.
should be based primarily on achieving adequate compaction
3.2.11 permeability, n—of geotextiles, hydraulic conductiv- without damaging the drainage panel, while also achieving
intimate contact with the trench wall or backfill material, or
ity.
–1
both. Excessive compaction efforts may damage geocomposite
3.2.12 permittivity, (γ), (T ), n—geotextiles, the volumetric
drainage materials and should be avoided. Skid vibratory
flow rate of water per unit cross-sectional area per unit head
compactors that are used in the trench adjacent to the panel can
under laminar flow conditions, in the normal direction through
damage the panel if not properly aligned and operated. Free-
a geotextile. (See Terminology D4439.)
flowing materials, such as pea-sized crushed stone and dry or
3.2.13 processed aggregates—aggregates that are screened,
moist sand is suitable in most cases and should be placed in
washed, mixed, or blended to produce a specific particle size
150 mm (6 in.) lifts. Placement of sand backfill can be done by
distribution.
flushing or puddling, but this should be used only when
3.2.14 standard proctor density—the maximum dry unit approved by the engineer. Post-installation settlement in the
weight of soil compacted at optimum moisture content, as
backfill will occur if the backfill is not properly densified.
obtained by laboratory test in accordance with Test Methods Significant settlement can cause shoulder drop-off settlement
D698.
and other pavement distress problems and structure damage to
the panels. Permeability of the backfill material must also be
4. Summary of Practice
considered; open-graded backfills will promote higher ground
waterflowtothedrainagesystem,willprovidealargersinkfor
4.1 This practice outlines the key installation criteria that
collecting water, and will also provide additional flow area
should be addressed for proper installation and maximum
during maximum rainfall events. Soil migration from adjacent
performance of geocomposite edge or underdrain materials, or
soils (trench walls) must be considered when using open-
both. The engineer should review the specifics of the system.
graded backfills.
Geocomposite drainage materials in this practice are products
meeting Specification D7001. Trench excavation, the depth of 7.2 Classification—Materials for potential use as embed-
drain placement, type of backfill, backfill placement, compac- ment and backfill of various components of subsurface drain-
tion of backfill, product fittings, and equipment used during age systems are classified in Fig. 3. They include natural,
installation are addressed in this practice. manufactured, and processed aggregates and the soil types
D6088 − 06 (2022)
FIG. 1 Typical Type and Arrangement of Drain
classified according to Practice D2487. Processed materials 7.4.1 Class IA Materials—Class IAmaterials provide maxi-
produced for highway construction (including coarse
mum stability and support for a given density due to angular
aggregate, base, subbase, and surface course materials) when interlockofparticles.Withminimumeffort,thesematerialscan
used for embedment and backfill, should be classified in
be installed in relatively high densities over a wide range of
accordance with this section and Fig. 3 according to particle
moisture contents. The high permeability of Class IAmaterials
size, shape, and gradation.
can aid in the performance of these drainage systems.
However, careful consideration must be given to the potential
7.3 Installation and Use—Fig. 4 provides recommendations
for migration of fines from adjacent materials into the open-
on installation and use based on class of soil or aggregates.
graded Class IA materials.
7.3.1 Use of Class III Soils and Aggregates—These materi-
als may be used as recommended in Fig. 4, provided the 7.4.2 Class IB Materials—Class IB materials are processed
permeability of the material is adequate and approved by the by mixing Class IA and natural or processed sands to produce
engineer. a particle size distribution that minimizes migration from
7.3.2 Use of Class IVA, Class IVB and Class V Soils and adjacent materials that contain fines. They are more densely
Frozen Materials—These materials are not recommended for
graded than Class IAmaterials and thus require more compac-
backfill and shall be excluded from the final backfill except
tive effort to achieve the minimum density specified. When
where approved by the engineer.
properly compacted, Class IB materials offer high stiffness and
strength.ClassIBmaterialsmayberelativelyfreedraining,but
7.4 Description of Backfill Material—Paragraphs 7.4.1 –
the amount and gradation of fines must be controlled.
7.4.5 describe characteristics of materials recommended for
backfill. Consideration must be given to the potential for 7.4.3 Class II Materials—Class II materials provide a rela-
migration of fines from adjacent materials into the backfill (see tively high level of structural support. Open-graded groups
Appendix X1). may allow migration and gradations shall be checked for
D6088 − 06 (2022)
NOTE 1—Drain positioning gate should be located and adjusted to position, and hold the geocomposite drain against the trench wall, to prevent possible “J”-ing or “C”-ing of the drain during
backfilling and compaction.
FIG. 2 Proper Horizontal Alignment

D6088 − 06 (2022)
NOTE 1—The Attenberg Limits shown in this figure are determined per Test Methods D4318.
FIG. 3 Classification of Materials for Potential Use as Embedment and Backfill of Various Components of Subsurface Drainage Systems
compatibility with adjacent material. Typically, Class II mate- vide satisfactory levels of structural support once proper
rials consist of rounded particles and are less stable than density is achieved. Fines content should be minimized for
angular materials unless they are confined and compacted. optimum permeability.
7.4.4 Class III Materials—Class III materials provide less 7.4.5 Class IVA Materials—Class IVA materials require a
support for a given density than Class I or Class II materials. geotechnical evaluation prior to use. These materials may not
Higher levels of compactive effort may be required unless be appropriate due to poor permeability or water caused
moisture content is carefully controlled. These materials pro- instability, particularly under wheel loads.
D6088 − 06 (2022)
FIG. 4 Recommendations for Installation and Use of Soils and Aggregrate for Foundation, Embedment,
...