ASTM D6103/D6103M-17e1

Standard Test Method for Flow Consistency of Controlled Low Strength Material (CLSM)

SIGNIFICANCE AND USE
5.1 This test method is intended to provide the user with a procedure to determine the fluidity of CLSM mixtures for use as backfill or structural fill.  
5.2 This test method is considered applicable to fresh CLSM containing only sand as the aggregate or having coarse aggregate smaller than 19.0 mm [3/4 in.]. If the coarse aggregate is larger than 19.0 mm [3/4 in.], the test method is applicable when it is made on the fraction of CLSM passing a 19.0 mm [3/4 in.] sieve, with the larger aggregate being removed in accordance with the section on Additional Procedures for Large Maximum size Aggregate Concrete in Practice C172/C172M.
Note 1: Removing the coarse aggregate will alter the characteristics of the mix and therefore will give information only about the remaining material. It is suggested that for mixes containing coarse aggregate 19.0 mm [3/4 in.] or larger, a measurement of the slump by Test Method C143/C143M is more appropriate.  
5.3 For non-flowable CLSM, or for mixtures that do not come out of the flow cylinder easily, measure the slump as outlined in Test Method C143/C143M.  
5.4 This test method is one of a series of quality control tests that can be performed on CLSM during construction to monitor compliance with specification requirements. The other tests that can be used during construction control are Test Methods D4832, D6023, and D6024/D6024M.
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 Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 This test method covers the procedure for determination of the flow consistency of fresh Controlled Low Strength Material (CLSM). This test method applies to flowable CLSM with a maximum particle size of 19.0 mm [3/4 in.] or less, or to the portion of CLSM that passes a 19.0 mm [3/4 in.] sieve.  
1.2 The CLSM used to make the molded specimens shall be sampled after all on-site adjustments have been made to the mixture proportions, including the addition of mix water and any admixtures.  
1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 unless superseded by this test method.  
1.3.1 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to the accuracy to which the data can be applied in design or other uses, or both. How one applies the results obtained using this standard is beyond its scope.  
1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.  
1.4.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight) while the unit for mass is slugs. The rationalized slug unit is not given, unless dynamic (F=ma) calculations are involved.  
1.4.2 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This implicitly combines two separate systems of units: that is, the absolute system and the gravitational system. It is scientifically undesirable to combine two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational sys...

General Information

• Status: Published
• Publication Date: 31-Oct-2017
• ICS: 91.100.99 - Other construction materials
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.15 - Stabilization With Admixtures

Relations

• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM C125-19a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2019
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM C125-19 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jan-2019
• Refers: ASTM C125-18b - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Oct-2018
• Refers: ASTM C125-18a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jul-2018
• Refers: ASTM C125-18 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jan-2018
• Refers: ASTM D4832-16 - Standard Test Method for Preparation and Testing of Controlled Low Strength Material (CLSM) Test Cylinders
• Effective Date: 15-Dec-2016
• Refers: ASTM C125-16 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2016
• Refers: ASTM D5971/D5971M-16 - Standard Practice for Sampling Freshly Mixed Controlled Low-Strength Material
• Effective Date: 01-Dec-2016
• Refers: ASTM D6023-16 - Standard Test Method for Density (Unit Weight), Yield, Cement Content, and Air Content (Gravimetric) of Controlled Low-Strength Material (CLSM)
• Effective Date: 01-Dec-2016
• Refers: ASTM D6024/D6024M-16 - Standard Test Method for Ball Drop on Controlled Low Strength Material (CLSM) to Determine Suitability for Load Application
• Effective Date: 01-Dec-2016
• Refers: ASTM C125-15b - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2015
• Refers: ASTM D6023-15 - Standard Test Method for Density (Unit Weight), Yield, Cement Content, and Air Content (Gravimetric) of Controlled Low-Strength Material (CLSM)
• Effective Date: 15-Nov-2015
• Refers: ASTM D6024/D6024M-15 - Standard Test Method for Ball Drop on Controlled Low Strength Material (CLSM) to Determine Suitability for Load Application
• Effective Date: 01-Jul-2015

Overview

ASTM D6103/D6103M-17e1 is the internationally recognized standard test method for determining the flow consistency of Controlled Low Strength Material (CLSM), commonly referred to as flowable fill. Published by ASTM International, this test method provides guidance for evaluating the fluidity of fresh CLSM mixtures, primarily intended for use as backfill or structural fill in civil engineering and construction applications. The standard is applicable to CLSM containing predominantly fine aggregates (sand) or coarse materials smaller than 19.0 mm (3/4 in.), ensuring quality control during placement and compliance with project specifications.

Key Topics

• Flow Consistency Assessment: Establishes a standardized procedure for measuring the spread (flow) of CLSM using a specified flow cylinder, providing data on material fluidity.
• Applicability: Designed for fresh CLSM mixtures with aggregate sizes up to 19.0 mm (3/4 in.). For larger aggregates, the test is conducted on the fines that pass through a 19.0 mm sieve, with coarser material removed.
• Alternate Methods: Recommends using ASTM C143/C143M slump testing for non-flowable CLSM mixtures or when coarse aggregate exceeds specified limits.
• Quality Control: One of several quality assurance measures available for in-field monitoring of CLSM during construction, promoting consistent material performance.
• SI and Inch-Pound Units: Provides guidance for test execution using both SI and inch-pound units, emphasizing accuracy and consistency in reporting.

Applications

The ASTM D6103/D6103M-17e1 standard plays a critical role in a wide range of construction and geotechnical engineering projects where CLSM is used for:

• Trench Backfill: Ensuring uniform flow and consolidation in utility trenches and around pipes, minimizing future settlement issues.
• Structural Fill: Providing a controlled, low-strength base or subgrade in pavement and foundation construction.
• Soil Replacement: Replacing unsuitable or unstable soils with CLSM to enhance ground stability without requiring mechanical compaction.
• Void Filling: Efficiently filling abandoned utility lines, tanks, or other voids where material must flow easily to fill all spaces.
• Quality Control During Placement: Allowing field and laboratory personnel to monitor CLSM consistency, adjusting mixtures as needed to meet fluidity and strength requirements.

Related Standards

Several ASTM standards are referenced within ASTM D6103/D6103M-17e1, supporting broader quality assurance for CLSM and related materials:

• ASTM C143/C143M: Slump test for hydraulic-cement concrete, used for non-flowable CLSM or mixtures with coarse aggregate over 19.0 mm.
• ASTM C125 & D653: Terminology for concrete, aggregates, soil, and rock, providing clarity in definitions.
• ASTM D172/C172M: Practice for sampling freshly mixed concrete, applicable for sample preparation.
• ASTM D4832: Test method for CLSM test cylinders, assessing strength and other mechanical properties.
• ASTM D6023: Test method for determining density, yield, cement content, and air content of CLSM.
• ASTM D6024/D6024M: Ball drop test for assessing load application suitability of CLSM.
• ASTM D3740: Practice outlining requirements for agencies conducting soil and rock testing.

Practical Value

By following ASTM D6103/D6103M-17e1, construction professionals and material suppliers ensure the proper flowability of CLSM, leading to improved placement, reduced risk of voids or settlement, and better overall performance. Consistent testing helps maintain compliance with project specifications, minimizes costly errors, and supports the production of high-quality, reliable fill materials across diverse civil engineering projects.

Keywords: ASTM D6103, CLSM, flowable fill, flow consistency, backfill, construction quality control, structural fill, standard test method, fluidity testing, soil stabilization.

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.
´1
Designation: D6103/D6103M − 17
Standard Test Method for
Flow Consistency of Controlled Low Strength Material
(CLSM)
This standard is issued under the fixed designation D6103/D6103M; 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.
ε NOTE—Editorially corrected units of measurement statement in June 2021.
1. Scope* separate systems of units: that is, the absolute system and the
gravitational system. It is scientifically undesirable to combine
1.1 This test method covers the procedure for determination
two separate sets of inch-pound units within a single standard.
of the flow consistency of fresh Controlled Low Strength
As stated, this standard includes the gravitational system of
Material (CLSM). This test method applies to flowable CLSM
inch-pound units and does not use/present the slug unit for
with a maximum particle size of 19.0 mm [ ⁄4 in.] or less, or to
mass. However, the use of balances or scales recording pounds
the portion of CLSM that passes a 19.0 mm [ ⁄4 in.] sieve.
of mass (lbm) or recording in lbm/ft shall not be regarded as
1.2 The CLSM used to make the molded specimens shall be
nonconformance with this standard.
sampled after all on-site adjustments have been made to the
1.5 CLSM is also known as flowable fill, controlled density
mixture proportions, including the addition of mix water and
fill, soil-cement slurry, soil-cement grout, unshrinkable fill,
any admixtures.
K-Krete, and other similar names.
1.3 All observed and calculated values shall conform to the
1.6 The text of this standard references notes and footnotes
guidelines for significant digits and rounding established in
which provide explanatory material. These notes and footnotes
Practice D6026 unless superseded by this test method.
(excluding those in tables and figures) shall not be considered
1.3.1 The method used to specify how data are collected,
as requirements of the standard.
calculated, or recorded in this standard is not directly related to
1.7 This standard does not purport to address all of the
theaccuracytowhichthedatacanbeappliedindesignorother
safety concerns, if any, associated with its use. It is the
uses, or both. How one applies the results obtained using this
responsibility of the user of this standard to establish appro-
standard is beyond its scope.
priate safety, health, and environmental practices and deter-
1.4 Units—The values stated in either SI units or inch-
mine the applicability of regulatory limitations prior to use.
pound units are to be regarded separately as standard. The
1.8 This international standard was developed in accor-
values stated in each system may not be exact equivalents;
dance with internationally recognized principles on standard-
therefore,eachsystemshallbeusedindependentlyoftheother.
ization established in the Decision on Principles for the
Combining values from the two systems may result in noncon-
Development of International Standards, Guides and Recom-
formance with the standard.
mendations issued by the World Trade Organization Technical
1.4.1 The gravitational system of inch-pound units is used
Barriers to Trade (TBT) Committee.
when dealing with inch-pound units. In this system, the pound
(lbf) represents a unit of force (weight) while the unit for mass
2. Referenced Documents
is slugs.The rationalized slug unit is not given, unless dynamic
2.1 ASTM Standards:
(F=ma) calculations are involved.
C125 Terminology Relating to Concrete and Concrete Ag-
1.4.2 It is common practice in the engineering/construction
gregates
profession to concurrently use pounds to represent both a unit
C143/C143M Test Method for Slump of Hydraulic-Cement
of mass (lbm) and of force (lbf). This implicitly combines two
Concrete
C172/C172M Practice for Sampling Freshly Mixed Con-
crete
Thistestmethodisunder the jurisdiction ofASTM CommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.15 on Stabilization With
Admixtures.
Current edition approved Nov. 1, 2017. Published November 2017. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 1997. Last previous edition approved in 2004 as D6103 – 04, which contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
was withdrawn July 2013 and reinstated in November 2017. DOI: 10.1520/D6103- Standards volume information, refer to the standard’s Document Summary page on
17E01. the ASTM website.
*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
´1
D6103/D6103M − 17
mm [ ⁄4 in.] or larger, a measurement of the slump by Test Method
D653 Terminology Relating to Soil, Rock, and Contained
C143/C143M is more appropriate.
Fluids
D3740 Practice for Minimum Requirements for Agencies
5.3 For non-flowable CLSM, or for mixtures that do not
Engaged in Testing and/or Inspection of Soil and Rock as come out of the flow cylinder easily, measure the slump as
Used in Engineering Design and Construction
outlined in Test Method C143/C143M.
D4832 Test Method for Preparation and Testing of Con-
5.4 Thistestmethodisoneofaseriesofqualitycontroltests
trolled Low Strength Material (CLSM) Test Cylinders
thatcanbeperformedonCLSMduringconstructiontomonitor
D5971/D5971M Practice for Sampling Freshly Mixed Con-
compliance with specification requirements. The other tests
trolled Low-Strength Material
that can be used during construction control are Test Methods
D6023 Test Method for Density (Unit Weight), Yield, Ce-
D4832, D6023, and D6024/D6024M.
ment Content, and Air Content (Gravimetric) of Con-
NOTE 2—The quality of the result produced by this standard is
trolled Low-Strength Material (CLSM)
dependent on the competence of the personnel performing it, and the
D6024/D6024M Test Method for Ball Drop on Controlled
suitability of the equipment and facilities used. Agencies that meet the
criteria of Practice D3740 are generally considered capable of competent
Low Strength Material (CLSM) to Determine Suitability
and objective testing/sampling/inspection/etc. Users of this standard are
for Load Application
cautioned that compliance with Practice D3740 does not in itself assure
D6026 Practice for Using Significant Digits in Geotechnical
reliable results. Reliable results depend on many factors; Practice D3740
Data
provides a means of evaluating some of those factors.
3. Terminology
6. Apparatus
3.1 Definitions—For definitions of common technical terms
6.1 Flow Cylinder—The flow cylinder shall be a 150 6 3.0
used in this standard, refer to Terminology standards C125 and
mm [6 6 0.125 in.] length of 76 6 3.0 mm [3 6 0.125 in.]
D653.
inside diameter, straight tubing of steel, plastic or other
3.2 Definitions of Terms Specific to This Standard:
non-absorbent material, non-reactive with CLSM containing
3.2.1 controlled low strength material (CLSM), n—a mix-
portland cement, fly ash or other supplementary cementitious
ture of soil or aggregates (sand, gravel, or both), cementitious
materials or additives. The flow cylinder shall be constructed
materials, water and sometimes admixtures, that hardens into a
such that the planes of the ends are parallel to one another and
material with a higher strength than the soil, but less than 8400
perpendicular to the longitudinal axis of the cylinder. The flow
kPa [1200 psi].
cylinder shall have a smooth interior, open at both ends and a
3.2.1.1 Discussion—Used as a replacement for compacted
rigid shape that is able to hold its dimensions and under
backfill, CLSM can be placed as a slurry, or a mortar, or a
conditions of severe use.
compacted material and typically has strengths of 350 to 700
6.2 Sampling and Mixing Receptacle—The receptacle shall
kPa [50 to 100 psi] for most applications.
beasuitablecontainer,wheelbarrow,etc.,ofsufficientcapacity
3.2.2 flow consistency, n—a measurement of the spread of a
to allow easy sampling and remixing of the CLSM.
predetermined volume of CLSM achieved by removal of the
6.3 Filling Apparatus—Scoop, shovel, bucket, or pail of
flow cylinder within a specified time.
sufficient capacity to facilitate filling of the flow cylinder in a
rapid, efficient manner.
4. Summary of Test Method
4.1 An open-ended cylinder is placed on a flat, level surface 6.4 Nonporous Surface—A 0.6-m [2.0-ft] square, or larger,
and filled with fresh CLSM. The cylinder is
...