ASTM D6460-24

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6460 − 19 D6460 − 24
Standard Test Method for
Determination of Rolled Erosion Control Product (RECP)
Performance in Protecting Earthen Channels from
Stormwater-Induced Erosion
This standard is issued under the fixed designation D6460; 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*
1.1 This test method covers the guidelines, requirements and procedures for evaluating the ability of Rolled Erosion Control
Products (RECPs) to protect earthen channels from stormwater-induced erosion. Critical elements of this protection are the ability
of the RECP to:
1.1.1 Neutralize and absorb the hydraulic force of stormwater, thereby reducing soil particle loosening through “scour”
mechanisms;
1.1.2 Slow runoff and encourage sedimentation, thereby reducing soil particle transport downstream;
1.1.3 Absorb shear forces of overland flow;
1.1.4 Trap soil particles beneath; and
1.1.5 Promote the establishment of vegetation.
1.2 This test method utilizes full-scale testing procedures, rather than reduced-scale (bench-scale) simulation, and is patterned after
conditions typically found on construction sites prior to and after revegetation work. Further, procedures for evaluation of baseline
conditions are provided. Thus, test preparation, test execution, data collection, data analysis and reporting procedures herein are
intended to be suitable for testing of bare soil, unvegetated RECP, vegetated soil and vegetated RECP conditions.
1.3 This test method provides a comparative evaluation of an unvegetated RECP to baseline bare soil conditions and a vegetated
RECP to a baseline, vegetated condition under controlled and documented conditions.
1.4 The values stated in SI units are to be regarded as standard. The inch-pound units given in parentheses are provided for
information purposes only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. Also, the user must comply with prevalent regulatory codes, such as OSHA (Occupational
Health and Safety Administration) guidelines, while using the test method.
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock; Subcommittee D18.25 on Erosion and Sediment Control Technology; and is the
direct responsibility of Section .02 on Erosion Control Blankets (ECBs).
Current edition approved July 15, 2019Feb. 1, 2024. Published August 2019March 2024. Originally approved in 1999. Last previous edition approved in 20122019 as
D6460–12. DOI: 10.1520/D6460-19.–19. DOI: 10.1520/D6460-24.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6460 − 24
1.6 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.
2. Referenced Documents
2.1 ASTM Standards:
C136C136/C136M Test Method for Sieve Analysis of Fine and Coarse Aggregates
D422 Test Method for Particle-Size Analysis of Soils (Withdrawn 2016)
3 3
D698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft (600 kN-m/m ))
D1556D1556/D1556M Test Method for Density and Unit Weight of Soil in Place by Sand-Cone Method (Withdrawn 2024)
D2922 Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth) (Withdrawn 2007)
D4318 Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils
D4595D4595/D4595M Test Method for Tensile Properties of Geotextiles by the Wide-Width Method
D6475 Test Method for Measuring Mass per Unit Area of Erosion Control Blankets
D6525D6525/D6525M Test Method for Measuring Nominal Thickness of Rolled Erosion Control Products (Withdrawn 2014)
D6526 Test Method for Analysis of Toluene by Capillary Column Gas Chromatography (Withdrawn 2018)
D6566 Test Method for Measuring Mass Per Unit Area of Turf Reinforcement Mats
D6567 Test Method for Measuring the Light Penetration of a Rolled Erosion Control Product (RECP)
D6818 Test Method for Tensile Properties of Rolled Erosion Control Products
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 erosion control blanket (ECB), n—a degradable material, composed primarily of processed natural organic materials,
manufactured or fabricated into rolls designed to reduce soil erosion and assist in the growth, establishment and protection of
vegetation.
3.1.2 erosion control net (ECN), n—a planar woven natural fiber or extruded synthetic mesh used as a component in the
manufacture of ECBs.
3.1.3 index test, n—a test procedure which may contain a known bias, but which may be used to establish an order for a set of
specimens with respect to the property of interest.
3.1.4 lot, n—a unit of production, or a group of other units or packages, taken for sampling or statistical examination, having one
or more common properties and being readily separable from other similar units.
3.1.5 natural, n—a class name of various fibers of animal, mineral or vegetable origin.
3.1.6 open weave textile (OWT), n—a temporary degradable ECB composed of natural or polymer yarns woven into a matrix used
to provide erosion control and facilitate vegetation establishment.
3.1.7 point gauge assembly, n—an adjustable, calibrated rack assembly mounted to a manually controlled pinion used to determine
the distance from a surface to a plane of reference. Typically, a point gauge assembly is mounted to a data acquisition cart
traversing a hydraulic testing flume and measures the relative distance from a surface within the flume to the zero mark of the
pinion housing. The rack is graduated and adjustable to accommodate variable offsets. Distance can be recorded manually or
electronically.
3.1.8 polymer, n—a chemical compound or mixture of compounds formed by polymerization and consisting essentially of
repeating molecular structural units.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
D6460 − 24
3.1.9 rolled erosion control product (RECP), n—a temporary degradable or long-term non-degradable material manufactured or
fabricated into rolls designed to reduce soil erosion and assist in the growth, establishment and protection of vegetation.
3.1.10 sample, n—a portion of material which is taken for testing or documentation and used in the laboratory as a source of
individual specimens.
3.1.11 shear stress, n—the force of flowing water applied to the surface of a channel in Newtons per square meter (pounds per
square foot); also, commonly referred to as “tractive force.”
3.1.12 temporary degradable, adj—composed of biologically, photochemically or otherwise degradable materials that temporarily
reduces soil erosion and enhances the establishment of vegetation.
3.1.13 turf reinforcement mat (TRM), n—in erosion control, a non-degradable geosynthetic or geocomposite processed into a
matrix sufficient to increase the stability threshold of otherwise unreinforced established vegetation.
3.1.13.1 Discussion—
Products in this category may incorporate ancillary degradable components to enhance the germination and establishment of
vegetation.
4. Summary of Test Method
4.1 The performance of an RECP in reducing stormwater-induced erosion is determined by subjecting the material to simulated
stormwater flow in a controlled and documented environment in reference to identical testing on baseline conditions.
4.2 Key elements of the testing process include:
4.2.1 Calibration of the stormwater simulation and measurement equipment;
4.2.2 Preparation of the test channel;
4.2.3 Documentation of the RECP to be tested (if applicable);
4.2.4 Installation of the RECP (if applicable);
4.2.5 Establishment of vegetative stand (if applicable);
4.2.6 Execution of the test;
4.2.7 Collection of hydraulic, topographical, and associated data;
4.2.8 Analysis of the resultant data; and
4.2.9 Reporting.
5. Significance and Use
5.1 This test method evaluates RECPs and their means of installation to:
5.1.1 Reduce soil loss and sediment concentrations in stormwater runoff under conditions of varying channel conditions and soil
type;
5.1.2 Function within a composite system acting as vegetative reinforcement; and
5.1.3 Improve water quality exiting the area disturbed by earthwork activity by minimizing mobilization of in-situ particles within
the streambed.
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5.2 This test method models and examines conditions typically found on construction sites involving earthwork activities,
including: highways and roads; airports; residential, commercial and industrial developments; pipelines, mines, and landfills; golf
courses; etc.
5.3 This test method is a performance test, but can be used for quality control to determine product conformance to project
specifications. Caution is advised since information regarding laboratory specific precision is incomplete. For project specific
conformance, unique project-specific conditions should be taken into consideration.
6. Apparatus
6.1 Water Delivery System—The water delivery system shall include pump(s), piping, channels, water control structures, and water
measurement instrumentation as necessary to achieve the desired hydraulic conditions. The water control structures shall regulate
and direct the flow into the desired test channel. Fig. 1 presents a schematic showing an example of a series of test channels and
water delivery system. The water delivery system shall be constructed such that turbulence at the entrance to the test channel is
minimized. Use of flow straighteners (for example, tube racks or vanes) are recommended to reduce turbulence and achieve
uniform flow conditions. A direct flow system (that is, controlled flow diverted from a natural waterway) may also be employed
for this purpose. Testing of bare soil conditions requires minimal channel gradient and minimal water flow. Testing of vegetated,
reinforced conditions typically requires steep gradient channels and a maximum discharge in excess of 2.8 cubic meters per second
(cms) (98.9 cubic feet per second (cfs)).
6.2 Water Source—Water derived for testing may be gravity fed or pump supplied to the testing facility in a closed loop or pass
through system. Water delivered should be regulated to ensure consistent discharge and be free of debris with little or no turbidity.
Discharge must be measured by hydraulic control structure, calibrated hydraulic structure, or calibrated flow meter.
6.3 Survey Apparatus—Channel gradient must be measured in a three-dimensional coordinate system with respect to a fixed
benchmark. A total station apparatus or survey level is required to determine elevations within the test reach. The total station
system is a standard surveying instrument capable of measuring distance simultaneously with vertical and horizontal angles to
determine the coordinates of a location (that is, X, Y and Z axis) within a defined coordinate system and store the data electronically
in a data logger. In lieu of a total station system, manual surveying equipment may be used. Precision and bias of either instrument
must be known. Soil loss may be recorded using survey apparatus referenced to a known bench mark or by calibrated point gauge
assembly referenced to relative locations within the facility.
6.4 Velocity Probe—A propeller-type probe shall be used to identify flow conditions during test operation. In lieu of a
propeller-type probe, other velocity measurement devices including electromagnetic or sonic type flow meters may be used,
provided that equivalent accuracy (65 %) is achievable. Periodic calibration and certification of this equipment shall be performed.
6.5 Earthwork Equipment—Typical equipment utilized in construction of test channels includes: skid loader, wheel barrow, hand
tamper, shovels, rakes, vibratory plate compactor and excavation template.
FIG. 1 Typical Closed Looped Water Delivery System
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6.6 Geotechnical Testing Equipment—Equipment sufficient to conduct testing described in Test Methods D422, C136C136/
C136M, D698, D4318, D1556D1556/D1556M, and D2922. Geotechnical evaluation may be outsourced to a laboratory with
sufficient equipment and expertise to conduct sediment characteristic evaluation.
6.7 Vegetative Stand Quantification Equipment—A calibrated template used to ensure height of vegetation and counting box are
necessary for vegetated testing. Vegetation is cut to a specific, uniform stand height by placing a template on the soil surface and
trimming blades/stems at the top of the template. An open, square box is used to count vegetation stems and blades to determine
stand density. The box may be constructed of metal or wood with an internal opening measuring 76.2 mm (3 in.) square and 25.4
to 50.8 mm (1 to 2 in.) in height.
6.8 Photographic Equipment—At a minimum, still and video footage must be recorded throughout the preparation and testing
process to document the testing. 35 mm still and 8 mm video formats or digital equivalents are acceptable.
6.9 Miscellaneous—Other miscellaneous equipment includes: meteorological equipment (wind speed, temperature, precipitation).
7. Procedure
7.1 Test Channel Preparation:
7.1.1 Construct earthen test channels using conventional earthwork placement techniques. A rectangular or trapezoidal cross
section channel may be used; however, a rectangular channel is recommended for consistency of construction and explicit
computation of shear stress. Perform compaction of channel bed material to create a geotechnically (structurally) stable subgrade.
General soil types to be used for testing shall be loam, clay and sand. Target grain sizes and plasticity indices are included in Table
1. Fig. 2 presents a schematic showing a typical test channel profile. Record geotechnical characteristics in file to include: visual
description and classification, grain size distribution (course and sub 200 fraction), plasticity indices, moisture-density relationship,
USDA, ASTM or USCS classification and in-situ compaction.
NOTE 1—Construction of steep slope and shallow soil layer plots may lead to geotechnical instability. Evaluation of test facility prior to operation is
advised.
7.1.2 Plate the channel surface with a minimum 30.5-cm (12-in.) thick veneer of test soil. Place soil in a minimum of two lifts
and compact to 90 6 3 % of standard Proctor density in accordance with Test Method D698. In the case previous testing was
completed in channel, remove top layer of soil to a depth of 25.4 mm (1 in.) deeper than deepest erosion and replace veneer. In-situ
density of soil must be measured for each lift utilizing Test Methods D1556D1556/D1556M or D2922.
7.1.3 Excavate and fill the soil surface to the design cross section and grade and ensure a smooth surface throughout the test reach.
The test channel may be comprised of a trapezoidal cross section or rectangular cross section. Trapezoidal cross section should
incorporate a 0.61-m (2-ft) bottom width and 2H:1V side slopes. A rectangular cross section must be 0.61 m (2 ft) minimum in
width. The test channels shall be a minimum of 12.2 m (40 ft) in length.
7.1.4 Locate test section sufficiently downstream of inlet structure or transitions of flow to ensure straight and parallel stream lines.
Flow should enter test section as uniform flow, or as close to uniform flow as possible. Maintenance or modification of the reach
of channel upstream from the test section may be required to provide similar roughness to the test section to attain near uniform
flow conditions entering the test section.
TABLE 1 Target Grain Sizes and Plasticity Indices
Particle size
Sand Loam Clay
(mm)
D (mm) 25 > D > 3.0 10 > D > 0.3 3.0 > D > 0.02
100 100 100 100
D (mm) 4.0 > D > 0.8 0.8 > D > 0.08 0.08 > D > 0.003
85 85 85 85
D (mm) 0.9 > D > 0.2 0.15 > D > 0.015 0.015 > D >
50 50 50 50
0.0008
D (mm) 0.3 > D > 0.03 > D > 0.001 D < 0.002
15 15 15 15
0.01
Plasticity N/A (nonplastic) 2 < PI < 8 10 < PI
Index
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FIG. 2 Typical Channel Profile
7.1.5 Prepare soil surface to mimic field conditions to be tested. In the case of bare soil testing, prepare a smooth or roughened
surface as necessary. If soil surface differs from final, compacted surface (that is, hand roughened), measure in-situ density of
surface by Test Methods D1556D1556/D1556M or D2922. If results are to be representative of bare soil conditions proceed to 7.2.
Otherwise, soil preparation methods for bare soil testing utilized as a baseline, control plot for product or vegetated testing should
be identical to soil preparation methods for the protected scenario.
7.1.6 Optional—If results are to be specific to RECP unvegetated performance, install RECP by manufacturer’s guidelines or by
specifications for testing required. Sample product to be tested (one per installation) and determine mass per unit area (Test Method
D6475), tensile strength and elongation (Test Method D4595D4595/D4595M for ECBs, Test Method D6818 for TRMs), thickness
(Test Method D6526), and light penetration (Test Method D6567). Record staple size, staple locations, product description, seam
details (that is, checkslots or overlaps used) and any other pertinent information. If the depth of flow will exceed the boundaries
of the installation (that is, a rectangular channel or trapezoidal channel with insufficient freeboard), secure the edges by placing
mechanical seal along edges of installation to prohibit flow from circumventing the RECP. Typically a mechanical seal is achieved
by securing dimensional lumber or angle iron along walls of testing facility, placed in contact with the RECP. Sufficient downward
pressure must be applied in placing the longitudinal, mechanical seal to ensure intimate contact with the RECP over the length of
the installation; however, the seal should not act as ancillary stabilization to the RECP. The angle iron or lumber is sealed with
a silicone sealant to ensure flow does not circumvent the mechanical seal. Mechanical seal should be installed to minimize
disturbance of the flow. Proceed to 7.2.
7.1.7 Optional—If results are to be specific to an unreinforced stand of vegetation, prepare seed bed and seed as desired. Provide
water and fertilizer or other additives as required to establish vegetation. Record seed type, preparation methodology, watering
schedule, fertilizer and additives used, and climatic variables over the entirety of the maturation period. Photograph test reach
weekly. Include photographs and notes regarding vegetation establishment in log with seed type, seed source and date of planting.
Allow vegetation to mature to reflect desired conditions. If a uniform vegetation height is desired, trim vegetation using hand
shears and height template, or by other suitable means, immediately prior to testing.
7.1.8 Optional—If results are to be specific to a stand of vegetation reinforced with an RECP, prepare and document seed bed as
described in 7.1.7, install the RECP as described in 7.1.6 and allow vegetation to mature as required, documenting maturation of
vegetation as described in 7.1.7. Prepare vegetation for testing as described in 7.1.7.
7.2 Pre-Test Documentation:
7.2.1 Maintain a test folder for each test cycle, including information on:
7.2.1.1 Site conditions;
7.2.1.2 Geotechnical and soil conditions including grain size distribution, liquid limit, plastic limit, plasticity index, USDA, USCS
or ASTM classification, K factor and in-situ compaction results;
7.2.1.3 Meteorological data from on-site weather station at time of testing (if testing outdoors);
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7.2.1.4 RECP product type/description including product data sheet and the following index test results from subsamples of the
products tested (if product test): Thickness (Test Method D6525D6525/D6525M), Mass per Unit Area (Test Method D6475 for
ECBs; Test Method D6566 for TRMs), Tensile Strength (Test Method D4595D4595/D4595M for ECBs; Test Method D6818 for
TRMs), and Light Penetration (Test Method D6567);
7.2.1.5 Vegetative component variables including seed type, seed source, stand density and maturity at time of testing, stand
height, visual classification of vegetation, and photo and note log from vegetation (if vegetative element incorporated in testing);
7.2.1.6 Installation procedure including dates of installation and descriptions of RECP and vegetative component incorporated.
Include all documentation listed in 7.1.6 and 7.1.7;
7.2.1.7 Photo documentation of installation immediately prior to testing; and
7.2.1.8 Document any conditions not specifically mentioned herein that could potentially influence the results of testing.
7.3 Initial Data Collection and Test Preparation:
7.3.1 Immediately prior to testing, delineate cross sections for data acquisition. At a minimum, eight cross sections should be
included through the test reach, with a maximum spacing between sections of one channel width in the direction of flow. Locate
data acquisition locations within each cross section to record water surface elevation and bed elevation. At a minimum, three data
acquisition locations along the bed of the channel and two data acquisition locations on each bank of the channel (if using a
trapezoidal section) must be identified and monitored at each cross section. Record the elevation of each data acquisition location
by survey apparatus or point gauge assembly. If using a point gauge assembly in a relative frame of reference, determine the
longitudinal slope of the installation by survey apparatus. Elevation readings can be sensitive to the diameter of the probe (rod or
point gauge assembly) in contact with the ground surface. Thus, the point gauge assembly or survey rod should include an
extension rod between 6.4 mm (0.25 in.) and 9.5 mm (0.375 in.) in diameter to make contact with the ground surface.
7.3.2 If vegetative component is incorporated in testing, quantify vegetative stand density using count box described in 6.7. A
minimum of three vegetation stem density counts are to be performed. Place count box on ground surface; count and record the
number of stems and the number of blades within the opening of the box. Three vegetation stem density counts are to be performed;
one located within the upstream, middle and downstream third of the test section. Minimize damage to vegetated system by
limiting foot traffic and stepping carefully around vegetation stem/blade density count location. Subsequent counts during testing
are to be performed in the same location as the initial count. Document condition of vegetation immediately prior to testing,
recording stand height as obtained by trimming to template height, density obtained from box counts, photographs and video
footage and visual classification of vegetative stand. Classify and record condition of vegetation as described in USDAAgricultural
Handbook #667 (USDA 1987). If variable vegetation height is used, record description of vegetation and a range of heights and
USDA classification.
7.3.3 Determine initial, target discharge. Initial discharge determination must consider conditions to be tested (bare soil,
unvegetated RECP, bare vegetation or reinforced vegetation), slope of test channel, and cross section size and shape of channel.
The objective of the performance test is to subject the installation incrementally increasing hydraulic forces, thus, the initial
discharge should cause little migration of soil from the test channel. Each subsequent target discharge will be determined from the
computation of hydraulic forces of the previous test.
7.3.4 Prepare facility for testing. Provide access to each data acquisition cross section to permit measurement of bed elevation
without walking on channel surface. Provide access to each data acquisition cross section to permit measurement of water surface
elevation by means of survey apparatus or point gauge assembly.
7.4 Test Operation and Data Collection:
7.4.1 Include the following test data: operator name and title; actual discharge recorded during testing, time flow began; time flow
stopped; time runoff stopped; flow depths; and measured velocities. Also record accuracy of all instruments
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