ASTM D6024/D6024M-16

Standard Test Method for Ball Drop on Controlled Low Strength Material (CLSM) to Determine Suitability for Load Application

SIGNIFICANCE AND USE
5.1 This test method is used primarily as a field test to determine the readiness of the CLSM to accept loads prior to adding a temporary or permanent wearing surface.  
5.2 This test method is not meant to predict the load bearing strength of a CLSM mixture.  
5.3 This test 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 D6103.  
Note 1: 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/and the like. 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 explains the determination of the ability of Controlled Low Strength Material (CLSM) to withstand loading by repeatedly dropping a metal weight onto the in-place material.  
1.2 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.  
1.2.1 The procedures used to specify how data are collected/recorded and 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 these test methods to consider significant digits used in analysis methods for engineering data.  
1.3 Units—The values stated in either SI units or inch-pound units presented in brackets are to be regarded separately as standard. The values stated in each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 CLSM is also known as flowable fill, controlled density fill, soil-cement slurry, soil-cement grout, unshrinkable fill, “K-Krete,” and other similar names.  
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 and health practices and determine the applicability of regulatory limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.2)

General Information

• Status: Published
• Publication Date: 30-Nov-2016
• ICS: 91.100.01 - Construction materials in general
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.15 - Stabilization With Admixtures

Relations

• Replaces: 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-Dec-2016
• 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 C125-16 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2016
• 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 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 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 C125-15a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jul-2015
• Refers: ASTM C125-15 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Feb-2015

Overview

ASTM D6024/D6024M-16 is the Standard Test Method for Ball Drop on Controlled Low Strength Material (CLSM) to Determine Suitability for Load Application. This standard, developed by ASTM International, describes a field procedure for assessing the readiness of CLSM-commonly known as flowable fill, controlled density fill, soil-cement slurry, or unshrinkable fill-to accept loads before the placement of a temporary or permanent wearing surface. The ball drop test provides a practical, on-site quality control method to help construction teams confirm compliance with specifications and optimize field operations.

Key Topics

• Test Methodology: The procedure involves dropping a half-spherical weight multiple times onto the surface of in-place CLSM and measuring the indentation’s diameter to assess material readiness for load application.
• Field Application: Designed as a rapid, straightforward method for the field, enabling real-time decision-making during construction projects.
• Readiness Evaluation: Specifically used to judge whether CLSM is ready for further load or covering, not to predict ultimate strength.
• Quality Control: One of several tests recommended for construction control and compliance monitoring alongside ASTM D4832, D6023, and D6103.
• Reporting Requirements: Requires documenting pertinent information such as location, operator, CLSM type, and the results of the indentation and surface water observation.
• Significance of Results: Emphasizes competence of testing personnel and adequacy of equipment following guidelines like ASTM D3740 for quality assurance.
• Units and Precision: Supports both SI and inch-pound units, which must be used independently to ensure compliance with the standard.

Applications

• Utility Trench Backfill: Commonly used to determine when CLSM is solid enough for backfilling or covering in utility trench applications, supporting construction sequencing.
• Pavement Subbase: Helps establish when roadway subbase layers constructed with CLSM can accept traffic loads or overlay materials.
• General Construction Fill: Applicable in projects where controlled low strength materials are used as alternatives to compacted soils, such as soil stabilization, structural fills, or void filling.
• Infrastructure Projects: Supports inspections and quality control for infrastructure installation, including pipes, culverts, foundations, or roadways using flowable fill.
• Material Compliance Monitoring: Ensures that delivered or mixed CLSM meets project specification requirements for load readiness and safety.

Related Standards

• ASTM D4832 - Test Method for Preparation and Testing of Controlled Low Strength Material (CLSM) Test Cylinders
• ASTM D6023 - Test Method for Density (Unit Weight), Yield, Cement Content, and Air Content (Gravimetric) of CLSM
• ASTM D6103 - Test Method for Flow Consistency of Controlled Low Strength Material (CLSM) (Withdrawn 2013; refer to historical usage)
• ASTM D6026 - Practice for Using Significant Digits in Geotechnical Data
• ASTM D3740 - Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• ASTM C125 & D653 - Terminology relating to concrete, aggregates, soils, and fluids

Practical Value

Implementing ASTM D6024/D6024M-16 improves the efficiency and safety of projects utilizing controlled low strength material. By providing a standard field method for testing load readiness, it assists engineers, contractors, and quality control personnel in making informed decisions on sequencing construction activities. The standard supports project compliance, minimizes the risk of premature loading, and helps ensure the long-term performance of backfills and subbases.

Keywords: Controlled Low Strength Material, CLSM, flowable fill, ball drop test, field testing, load suitability, construction quality control, trench backfill, pavement subbase, ASTM standards, 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.
Designation: D6024/D6024M − 16
Standard Test Method for
Ball Drop on Controlled Low Strength Material (CLSM) to
Determine Suitability for Load Application
This standard is issued under the fixed designation D6024/D6024M; 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* hydraulic cementitious mixtures are caustic and may cause
chemical burns to skin and tissue upon prolonged exposure. )
1.1 This test method explains the determination of the
ability of Controlled Low Strength Material (CLSM) to with-
2. Referenced Documents
stand loading by repeatedly dropping a metal weight onto the 3
2.1 ASTM Standards:
in-place material.
C125 Terminology Relating to Concrete and Concrete Ag-
gregates
1.2 All observed and calculated values shall conform to the
D653 Terminology Relating to Soil, Rock, and Contained
guidelines for significant digits and rounding established in
Fluids
Practice D6026.
D3740 Practice for Minimum Requirements for Agencies
1.2.1 Theproceduresusedtospecifyhowdataarecollected/
Engaged in Testing and/or Inspection of Soil and Rock as
recorded and calculated in the standard are regarded as the
Used in Engineering Design and Construction
industry standard. In addition, they are representative of the
D4832 Test Method for Preparation and Testing of Con-
significant digits that generally should be retained. The proce-
trolled Low Strength Material (CLSM) Test Cylinders
dures used do not consider material variation, purpose for
D6023 Test Method for Density (Unit Weight), Yield, Ce-
obtaining the data, special purpose studies, or any consider-
ment Content, and Air Content (Gravimetric) of Con-
ations for the user’s objectives; and it is common practice to
trolled Low-Strength Material (CLSM)
increase or reduce significant digits of reported data to be
D6026 Practice for Using Significant Digits in Geotechnical
commensuratewiththeseconsiderations.Itisbeyondthescope
Data
of these test methods to consider significant digits used in
D6103 Test Method for Flow Consistency of Controlled
analysis methods for engineering data.
Low Strength Material (CLSM) (Withdrawn 2013)
1.3 Units—The values stated in either SI units or inch-
3. Terminology
pound units presented in brackets are to be regarded separately
3.1 Definitions:
as standard. The values stated in each system shall be used
3.1.1 For definitions of common technical terms in this test
independently of the other. Combining values from the two
method, refer to Terminology standards C125 and D653.
systems may result in non-conformance with the standard.
3.1.2 Controlled Low Strength Material (CLSM), n—a mix-
1.4 CLSM is also known as flowable fill, controlled density
ture of soil, aggregates (sand, gravel, or both), cementitious
fill, soil-cement slurry, soil-cement grout, unshrinkable fill, materials, water, and sometimes admixtures, that hardens into
“K-Krete,” and other similar names. a material with a higher strength than the soil, but less than
8400 kPa [1200 psi].
1.5 This standard does not purport to address all of the
3.1.2.1 Discussion—Used as a replacement for compacted
safety concerns, if any, associated with its use. It is the
backfill, CLSM can be placed as a slurry, a mortar, or a
responsibility of the user of this standard to establish appro-
compacted material and typically has strengths of 350 to 700
priate safety and health practices and determine the applica-
kPa [50 to 100 psi] for most applications.
bility of regulatory limitations prior to use. (Warning—Fresh
Section on Safety Precautions, Manual of Aggregate and Concrete Testing,
Annual Book of ASTM Standards, Vol. 04.02.
1 3
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Rock and is the direct responsibility of Subcommittee D18.15 on Stabilization With contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Admixtures. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 1, 2016. Published January 2017. Originally the ASTM website.
approved in 1995. Last previous edition approved in 2015 as D6024 – 07. DOI: The last approved version of this historical standard is referenced on
10.1520/D6024_D6024M-16. www.astm.org.
*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
D6024/D6024M − 16
4. Summary of Test Method
4.1 A half spherical weight is dropped five times from a
specific height onto the surface of in-place CLSM. The
diameteroftheresultingindentationismeasuredandcompared
to established criteria.The indentation is inspected for any free
water brought to the surface from the impact.
5. Significance and Use
5.1 This test method is used primarily as a field test to
determine the readiness of the CLSM to accept loads prior to
adding a temporary or permanent wearing surface.
5.2 This test method is not meant to predict the load bearing
strength of a CLSM mixture.
5.3 This test 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 D6103.
NOTE 1—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/and the like. 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.
FIG. 1 Ball-drop Apparatus
6. Apparatus
leveled CLSM surface, with the handle in a vertical position
6.1 Ball-drop Apparatus—A Ball Penetration Apparatus
and free to slide through the frame. Put slight pressure on the
(Kelly Ball) that consists of a half sphere with a handle,
frame with your free hand to stabilize the device. Lift the
together weighing 14-15 kg [30-33 lb]. The half spherical
handle as far as possible allowing the top surface of the ball to
weight may be machined from metal stock or cast or spun with
contact the underside of the stirrup frame. Release the weight
a smooth finish and shall have a radius of 73 mm [2.875 in.] to
all
...

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: D6024/D6024M − 15 D6024/D6024M − 16
Standard Test Method for
Ball Drop on Controlled Low Strength Material (CLSM) to
Determine Suitability for Load Application
This standard is issued under the fixed designation D6024/D6024M; 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 explains the determination of the ability of Controlled Low Strength Material (CLSM) to withstand loading
by repeatedly dropping a metal weight onto the in-place material.
1.2 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice
D6026.
1.2.1 The procedures used to specify how data are collected/recorded and 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 these test methods to consider significant digits used in analysis methods for engineering data.
1.3 Units—The values stated in either SI units or inch-pound units presented in brackets are to be regarded separately as
standard. The values stated in each system shall be used independently of the other. Combining values from the two systems may
result in non-conformance with the standard.
1.4 CLSM is also known as flowable fill, controlled density fill, soil-cement slurry, soil-cement grout, unshrinkable fill,
“K-Krete,” and other similar names.
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 and health practices and determine the applicability of regulatory
limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and
tissue upon prolonged exposure. )
2. Referenced Documents
2.1 ASTM Standards:
C125 Terminology Relating to Concrete and Concrete Aggregates
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in
Engineering Design and Construction
D4832 Test Method for Preparation and Testing of Controlled Low Strength Material (CLSM) Test Cylinders
D6023 Test Method for Density (Unit Weight), Yield, Cement Content, and Air Content (Gravimetric) of Controlled
Low-Strength Material (CLSM)
D6026 Practice for Using Significant Digits in Geotechnical Data
D6103 Test Method for Flow Consistency of Controlled Low Strength Material (CLSM) (Withdrawn 2013)
3. Terminology
3.1 Definitions—For definitions of common technical terms in this test method, refer to Terminology standards C125 and D653.
3.1 Definitions of Terms Specific to This Standard:Definitions:
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.15 on Stabilization With
Admixtures.
Current edition approved July 1, 2015Dec. 1, 2016. Published July 2015January 2017. Originally approved in 1995. Last previous edition approved in 20072015 as
D6024 – 07. DOI: 10.1520/D6024_D6024M-15.10.1520/D6024_D6024M-16.
Section on Safety Precautions, Manual of Aggregate and Concrete Testing, Annual Book of ASTM Standards, Vol. 04.02.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. 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.
*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
D6024/D6024M − 16
3.1.1 For definitions of common technical terms in this test method, refer to Terminology standards C125 and D653.
3.1.2 Controlled Low Strength Material (CLSM), n—a mixture of soil, aggregates (sand, gravel, or both), cementitious
materials, potable water, and sometimes admixtures, that hardens into a material with a higher strength than the soil, but less than
8400 kPa [1200 psi].
3.1.2.1 Discussion—
Used as a replacement for compacted backfill, CLSM can be placed as a slurry, a mortar, or a compacted material and typically
has strengths of 350 to 700 kPa [50 to 100 psi] for most applications.
4. Summary of Test Method
4.1 A half spherical weight is dropped five times from a specific height onto the surface of in-place CLSM. The diameter of
the resulting indentation is measured and compared to established criteria. The indentation is inspected for any free water brought
to the surface from the impact.
5. Significance and Use
5.1 This test method is used primarily as a field test to determine the readiness of the CLSM to accept loads prior to adding
a temporary or permanent wearing surface.
5.2 This test method is not meant to predict the load bearing strength of a CLSM mixture.
5.3 This test 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
D6103.
NOTE 1—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/and the like. 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.
6. Apparatus
6.1 Ball-drop Apparatus—A Ball Penetration Apparatus (Kelly Ball) that consists of a half sphere with a handle, together
weighing 14-15 kg [30-33 lb]. The half spherical weight may be machined from metal stock or cast or spun with a smooth finish
and shall have a radius of 73 mm [2.875 in.] to 79 mm [3.125 in.]. A stirrup or frame approximately 270 mm [10.5 in.] wide and
approximately 140 mm [5.5 in.] high shall guide the handle such that the Kelly Ball falls freely and perpend
...