ASTM D8326-21

Standard Practice for Measurement of the Kinetic Energy of Simulated Rainfall

SIGNIFICANCE AND USE
5.1 When a raindrop impacts the surface of a soil, it expends its energy and begins the impact-induced soil erosion process. This kinetic energy of the raindrop is one factor influencing soil erosion. This practice provides a method to quantify the kinetic energy produced by rainfall simulators.  
5.2 Soil erosion is a concern that affects many industries. The highway and road construction industry is particularly interested in slope protection. There are many ECP manufacturers that rely on testing of their products using rainfall simulators to meet certain specifications set forth by different agencies.  
5.3 Laboratories that offer testing of ECPs use rainfall simulators. Many laboratories are able to adjust their rainfall simulators, the drop height of the raindrops, and even the slopes of the test plots they use to model expected, anticipated, or actual field conditions. The kinetic energy associated with the specific configuration of the simulator should be measured.  
5.4 Knowing the kinetic energy for the given simulator configuration will provide a way to set minimum and upper limit values so that comparisons between laboratories can be made as well as having a way to account for the differences between the laboratories. If there are minimum and upper limit values and the raindrop size is in the same range between laboratories, the kinetic energy between the laboratories should be similar. Once the kinetic energy is established for a given rainfall simulator configuration according to a specific standard, comparisons of the results for those specific standards can be made.
Note 2: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Pract...
SCOPE
1.1 This practice is used to measure the kinetic energy of rainfall simulators used by laboratories to evaluate soil erosion. The kinetic energy of raindrops is an important factor that should be considered when conducting soil erosion studies. Using the data collected from determining the raindrop size, this practice provides a method to uniformly calculate the kinetic energy which can be used to compare results from different laboratories.  
1.2 Many types of Erosion Control Products (ECPs) are evaluated for their ability to reduce soil erosion in laboratory and field settings using rainfall simulators. Rainfall simulators are used with test plots to simulate a specific condition that is or may be expected in the field. Rainfall simulators typically use drop emitters, sprinklers, or nozzles to create the raindrops. Each device produces different drops and since the rainfall simulators can be configured to produce different raindrop sizes and fall heights, the kinetic energy will be different. Therefore, the kinetic energy must be calculated for a given set of conditions in order to properly understand the impact of erosion for bare soil and the ECP.  
1.3 The upper limit of the size of a raindrop is generally accepted to be 7 mm. While it is possible to get a raindrop size between 6 and 7 mm occasionally, it is not common to get raindrop sizes above 6 mm.  
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.  
1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.  
1.5.1 The procedures used to specify how data are collected/recorded or calculated in the standard are regarded as the industry standard. In addition, they are representative of the s...

General Information

• Status: Published
• Publication Date: 31-Dec-2020
• ICS: 13.080.01 - Soil quality and pedology in general
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.25 - Erosion and Sediment Control Technology

Standards Content (Sample)

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: D8326 − 21
Standard Practice for
1
Measurement of the Kinetic Energy of Simulated Rainfall
This standard is issued under the fixed designation D8326; 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 dures used do not consider material variation, purpose for
obtaining the data, special purpose studies, or any consider-
1.1 This practice is used to measure the kinetic energy of
ations for the user’s objectives; and it is common practice to
rainfallsimulatorsusedbylaboratoriestoevaluatesoilerosion.
increase or reduce significant digits of reported data to be
The kinetic energy of raindrops is an important factor that
commensuratewiththeseconsiderations.Itisbeyondthescope
should be considered when conducting soil erosion studies.
of this standard to consider significant digits used in analysis
Using the data collected from determining the raindrop size,
methods for engineering design.
this practice provides a method to uniformly calculate the
kinetic energy which can be used to compare results from 1.6 This practice offers a set of instructions for performing
different laboratories. one or more specific operations. This document cannot replace
educationorexperienceandshouldbeusedinconjunctionwith
1.2 Many types of Erosion Control Products (ECPs) are
professional judgment. Not all aspects of this practice may be
evaluated for their ability to reduce soil erosion in laboratory
applicable in all circumstances. This ASTM standard is not
and field settings using rainfall simulators. Rainfall simulators
intended to represent or replace the standard of care by which
are used with test plots to simulate a specific condition that is
the adequacy of a given professional service must be judged,
or may be expected in the field. Rainfall simulators typically
nor should this document be applied without consideration of
usedropemitters,sprinklers,ornozzlestocreatetheraindrops.
a project’s many unique aspects. The word “Standard” in the
Each device produces different drops and since the rainfall
title of this document means only that the document has been
simulators can be configured to produce different raindrop
approved through the ASTM consensus process.
sizes and fall heights, the kinetic energy will be different.
1.7 This standard does not purport to address all of the
Therefore, the kinetic energy must be calculated for a given set
safety concerns, if any, associated with its use. It is the
of conditions in order to properly understand the impact of
responsibility of the user of this standard to establish appro-
erosion for bare soil and the ECP.
priate safety, health, and environmental practices and deter-
1.3 The upper limit of the size of a raindrop is generally
mine the applicability of regulatory limitations prior to use.
accepted to be 7 mm. While it is possible to get a raindrop size
1.8 This international standard was developed in accor-
between 6 and 7 mm occasionally, it is not common to get
dance with internationally recognized principles on standard-
raindrop sizes above 6 mm.
ization established in the Decision on Principles for the
1.4 Units—The values stated in SI units are to be regarded
Development of International Standards, Guides and Recom-
as standard. No other units of measurement are included in this
mendations issued by the World Trade Organization Technical
standard. Reporting of test results in units other than SI shall
Barriers to Trade (TBT) Committee.
not be regarded as nonconformance with this standard.
2. Referenced Documents
1.5 All observed and calculated values shall conform to the
2
2.1 ASTM Standards:
guidelines for significant digits and rounding established in
D653 Terminology Relating to Soil, Rock, and Contained
Practice D6026.
Fluids
1.5.1 Theproceduresusedtospecifyhowdataarecollected/
D3740 Practice for Minimum Requirements for Agencies
recorded or calculated in the standard are regarded as the
Engaged in Testing and/or Inspection of Soil and Rock as
industry standard. In addition, they are representative of the
Used in Engineering Design and Construction
significant digits that generally should be retained. The proce-
D6026 Practice for Using Significant Digits in Geotechnical
Data
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.25 on Erosion and
2
Sediment Control Technology. For referenced ASTM standards, visit the ASTM website,
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
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: D8326 − 20 D8326 − 21
Standard Practice for
1
Measurement of the Kinetic Energy of Simulated Rainfall
This standard is issued under the fixed designation D8326; 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 practice is used to measure the kinetic energy of rainfall simulators used by laboratories to evaluate soil erosion. The
kinetic energy of raindrops is an important factor that should be considered when conducting soil erosion studies. Using the data
collected from determining the raindrop size, this practice provides a method to uniformly calculate the kinetic energy which can
be used to compare results from different laboratories.
1.2 Many types of Erosion Control Products (ECPs) are evaluated for their ability to reduce soil erosion in laboratory and field
settings using rainfall simulators. Rainfall simulators are used with test plots to simulate a specific condition that is or may be
expected in the field. Rainfall simulators typically use drop emitters, sprinklers, or nozzles to create the raindrops. Each device
produces different drops and since the rainfall simulators can be configured to produce different raindrop sizes and fall heights,
the kinetic energy will be different. Therefore, the kinetic energy must be calculated for a given set of conditions in order to
properly understand the impact of erosion for bare soil and the ECP.
1.3 The upper limit of the size of a raindrop is generally accepted to be 7 mm. While it is possible to get a raindrop size between
6 and 7 mm occasionally, it is not common to get raindrop sizes above 6 mm.
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.
1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice
D6026.
1.5.1 The procedures used to specify how data are collected/recorded or calculated in the standard are regarded as the industry
standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not
consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives;
and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations.
It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.
1.6 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace
education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be
applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the
1
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.25 on Erosion and Sediment
Control Technology.
Current edition approved July 1, 2020Jan. 1, 2021. Published July 2020January 2021. Originally approved in 2020. Last previous edition approved in 2020 as D8326 - 20.
DOI: 10.1520/D8326-20.10.1520/D8326-21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D8326 − 21
adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s
many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through
the ASTM consensus process.
1.7 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.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in t
...