ASTM D75/D75M-19

Standard Practice for Sampling Aggregates

SIGNIFICANCE AND USE
4.1 Sampling is equally as important as the testing, and the sampler shall use every precaution to obtain samples that will show the nature and condition of the materials which they represent.  
4.2 Samples for preliminary investigation tests are obtained by the party responsible for development of the potential source (Note 3). Samples of materials for control of the production at the source or control of the work at the site of use are obtained by the manufacturer, contractor, or other parties responsible for accomplishing the work. Samples for tests to be used in acceptance or rejection decisions by the purchaser are obtained by the purchaser or his authorized representative.  
Note 3: The preliminary investigation and sampling of potential aggregate sources and types occupies a very important place in determining the availability and suitability of the largest single constituent entering into the construction. It influences the type of construction from the standpoint of economics and governs the necessary material control to ensure durability of the resulting structure, from the aggregate standpoint. This investigation should be done only by a responsible, trained, and experienced person. For more comprehensive guidance, see the appendixes.
SCOPE
1.1 This practice covers sampling of coarse and fine aggregates for the following purposes:  
1.1.1 Preliminary investigation of the potential source of supply,  
1.1.2 Control of the product at the source of supply,  
1.1.3 Control of the operations at the site of use, and  
1.1.4 Acceptance or rejection of the materials.  
Note 1: Sampling plans and acceptance and control tests vary with the type of construction in which the material is used.  
1.2 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.  
1.3 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.
Note 2: The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of Specification D3666 are generally considered capable of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Specification D3666 alone does not completely ensure reliable results. Reliable results depend on many factors; following the suggestions of Specification D3666 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.  
1.4 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.  
1.5 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2019
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: D04 - Road and Paving Materials
• Drafting Committee: D04.30 - Methods of Sampling

Relations

• Replaces: ASTM D75/D75M-14 - Standard Practice for Sampling Aggregates
• Effective Date: 01-Nov-2019
• Refers: ASTM E141-10(2023) - Standard Practice for Acceptance of Evidence Based on the Results of Probability Sampling
• Effective Date: 01-Nov-2023
• Refers: ASTM D2234/D2234M-19 - Standard Practice for Collection of a Gross Sample of Coal
• Effective Date: 01-Dec-2019
• Refers: ASTM D8-19 - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 01-Aug-2019
• Refers: ASTM D8-18c - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 15-Dec-2018
• Refers: ASTM D8-18b - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 15-Aug-2018
• Refers: ASTM D8-18a - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 01-Jul-2018
• Refers: ASTM E141-10(2018) - Standard Practice for Acceptance of Evidence Based on the Results of Probability Sampling
• Effective Date: 01-Apr-2018
• Refers: ASTM D8-18 - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 01-Feb-2018
• Refers: ASTM D2234/D2234M-17 - Standard Practice for Collection of a Gross Sample of Coal
• Effective Date: 15-Oct-2017
• Refers: ASTM D8-17c - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 15-Jul-2017
• Refers: ASTM D8-17b - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 15-Jun-2017
• Refers: ASTM D8-17a - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 01-May-2017
• Refers: ASTM D8-17 - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 01-Mar-2017
• Refers: ASTM D8-16b - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 01-Dec-2016

Overview

ASTM D75/D75M-19: Standard Practice for Sampling Aggregates is an internationally recognized standard developed by ASTM International. This standard specifies procedures for obtaining representative samples of coarse and fine aggregates. Proper sampling is critical to ensure aggregates used in construction, such as concrete, asphalt, and road materials, reflect the quality and properties of materials delivered, produced, or used at the site. ASTM D75/D75M-19 helps agencies, contractors, suppliers, and purchasers implement consistent, unbiased sampling processes that support reliable testing outcomes and informed decision-making in material acceptance, quality control, and compliance.

Key Topics

1. Purpose of Sampling

• Supports preliminary investigations of potential aggregate sources
• Facilitates control at the source of supply and at the construction site
• Provides basis for acceptance or rejection of aggregate materials based on test results

2. Responsibility for Sampling

• Preliminary source samples: By parties developing the source
• Production/control samples: By manufacturers or contractors
• Acceptance/rejection: By purchasers or their representatives

3. Methods of Securing Samples

• Sampling from flowing streams (bin or belt discharge)
• Sampling from conveyor belts
• Sampling from stockpiles, with or without power equipment
• Sampling from transportation units (trucks, rail cars, barges)
• Sampling from roadway bases and subbases prior to compaction

4. Precautions and Best Practices

• Every precaution must be taken to ensure that samples accurately represent the entire lot
• Avoid samples from segregated or contaminated areas
• Follow agreed sampling plans for unbiased results and consult relevant ASTM guidance, such as Specification D3666 for agency competence

5. Sample Size and Number

• Field sample size depends on aggregate type, test requirements, and production variability
• Sufficient increments should be combined to form representative field samples
• Standard minimum sample sizes help ensure reliable grading and quality analysis

Applications

ASTM D75/D75M-19 is widely used in:

• Highway and road construction for sampling aggregates used in pavement, base, and subbase layers
• Concrete production to ensure aggregate quality for structural integrity
• Quality assurance/control programs at quarries, concrete plants, and construction sites
• Acceptance testing by government agencies or private purchasers to verify compliance with specifications
• Investigation and development of new aggregate sources

Implementing this standard enables stakeholders to:

• Reduce risks of material quality issues and construction failure
• Make objective decisions regarding material approval and rejection
• Maintain traceability and documentation of sampling processes for future reference and audits

Related Standards

This standard should be used in conjunction with other ASTM and AASHTO standards, such as:

• ASTM C702/C702M: Practice for Reducing Aggregate Samples to Testing Size
• ASTM D3665: Practice for Random Sampling of Construction Materials
• ASTM D3666: Specification for Minimum Requirements for Agencies Testing and Inspecting Road and Paving Materials
• ASTM E105 & E122: Guidance on probability sampling and sample size calculation
• AASHTO T2: Standard Method of Test for Sampling Aggregates

By adhering to ASTM D75/D75M-19 and related guidance, construction professionals ensure representative aggregate sampling, accurate test results, and compliance with quality standards across the materials supply chain.

Keywords: aggregate sampling, ASTM D75, construction materials, quality control, coarse and fine aggregate, material acceptance, testing procedures, road materials, concrete aggregate sampling, standard sampling practice.

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: D75/D75M − 19 American Association State
Highway and Transportation
Officials Standard
AASHTO No.: T2
Standard Practice for
Sampling Aggregates
This standard is issued under the fixed designation D75/D75M; 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 sampling of coarse and fine aggre-
ization established in the Decision on Principles for the
gates for the following purposes:
Development of International Standards, Guides and Recom-
1.1.1 Preliminary investigation of the potential source of
mendations issued by the World Trade Organization Technical
supply,
Barriers to Trade (TBT) Committee.
1.1.2 Control of the product at the source of supply,
1.1.3 Control of the operations at the site of use, and
2. Referenced Documents
1.1.4 Acceptance or rejection of the materials.
2.1 ASTM Standards:
NOTE 1—Sampling plans and acceptance and control tests vary with the
C702/C702M Practice for Reducing Samples of Aggregate
type of construction in which the material is used.
to Testing Size
1.2 The text of this standard references notes and footnotes
D8 Terminology Relating to Materials for Roads and Pave-
which provide explanatory material. These notes and footnotes
ments
(excluding those in tables and figures) shall not be considered
D2234/D2234M Practice for Collection of a Gross Sample
as requirements of the standard.
of Coal
D3665 Practice for Random Sampling of Construction Ma-
1.3 The values stated in either SI units or inch-pound units
terials
are to be regarded separately as standard. The values stated in
D3666 Specification for Minimum Requirements for Agen-
each system may not be exact equivalents; therefore, each
cies Testing and Inspecting Road and Paving Materials
system shall be used independently of the other. Combining
E105 Practice for Probability Sampling of Materials
values from the two systems may result in nonconformance
E122 Practice for Calculating Sample Size to Estimate,With
with the standard.
Specified Precision, the Average for a Characteristic of a
NOTE 2—The quality of the results produced by this standard are
Lot or Process
dependent on the competence of the personnel performing the procedure
E141 Practice for Acceptance of Evidence Based on the
and the capability, calibration, and maintenance of the equipment used.
Results of Probability Sampling
Agencies that meet the criteria of Specification D3666 are generally
considered capable of competent and objective testing, sampling,
inspection, etc. Users of this standard are cautioned that compliance with 3. Terminology
Specification D3666 alone does not completely ensure reliable results.
3.1 Definitions—For definitions of terms used in this
Reliable results depend on many factors; following the suggestions of
practice, refer to Terminology D8.
Specification D3666 or some similar acceptable guideline provides a
means of evaluating and controlling some of those factors.
4. Significance and Use
1.4 This standard does not purport to address all of the
4.1 Sampling is equally as important as the testing, and the
safety concerns, if any, associated with its use. It is the
sampler shall use every precaution to obtain samples that will
responsibility of the user of this standard to establish appro-
show the nature and condition of the materials which they
priate safety, health, and environmental practices and deter-
represent.
mine the applicability of regulatory limitations prior to use.
4.2 Samples for preliminary investigation tests are obtained
by the party responsible for development of the potential
This practice is under the jurisdiction of ASTM Committee D04 on Road and
Paving Materials and is the direct responsibility of Subcommittee D04.30 on
Methods of Sampling. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2019. Published November 2019. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1920. Last previous edition approved in 2014 as D75/D75M – 14. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D0075_D0075M-19. 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
D75/D75M − 19
source (Note 3). Samples of materials for control of the veyor belt while the sample increments are being obtained.
productionatthesourceorcontroloftheworkatthesiteofuse Insert two templates, the shape of which conforms to the shape
are obtained by the manufacturer, contractor, or other parties of the belt in the aggregate stream on the belt, and space them
responsibleforaccomplishingthework.Samplesforteststobe such that the material contained between them will yield an
used in acceptance or rejection decisions by the purchaser are increment of the required weight (see Fig. 1). Carefully scoop
obtained by the purchaser or his authorized representative. all material between the templates into a suitable container and
collect the fines on the belt with a brush and dust pan and add
NOTE 3—The preliminary investigation and sampling of potential
to the container.
aggregate sources and types occupies a very important place in determin-
ing the availability and suitability of the largest single constituent entering
NOTE 5—Automatic belt samplers may be used as long as they are
into the construction. It influences the type of construction from the
properly maintained, and regular inspection ensures all material is being
standpoint of economics and governs the necessary material control to
removed from the belt (see Fig. 2).
ensure durability of the resulting structure, from the aggregate standpoint.
5.3.3 Sampling from Stockpiles—Avoid sampling coarse
This investigation should be done only by a responsible, trained, and
experienced person. For more comprehensive guidance, see the appen-
aggregate or mixed coarse and fine aggregate from stockpiles
dixes.
whenever possible, particularly when the sampling is done for
the purpose of determining aggregate properties that may be
5. Securing Samples
dependent upon the grading of the sample. If circumstances
make it necessary to obtain samples from a stockpile of coarse
5.1 General—Where practicable, samples to be tested for
aggregateorastockpileofcombinedcoarseandfineaggregate,
quality shall be obtained from the finished product. Samples
design a sampling plan for the specific case under consider-
fromthefinishedproducttobetestedforabrasionlossshallnot
ation to ensure that segregation does not introduce a bias in the
be subject to further crushing or manual reduction in particle
results. This approach will allow the sampling agency to use a
size in preparation for the abrasion test unless the size of the
sampling plan that will give a confidence in results obtained
finished product is such that it requires further reduction for
therefrom that is agreed upon by all parties concerned to be
testing purposes.
acceptable for the particular situation. The sampling plan shall
5.2 Inspection—Thematerialtobesampledshallbevisually
define the number of samples necessary to represent lots and
inspectedtodeterminediscerniblevariations.Ifanydiscernible
sublots of specific sizes. The sampling plan shall also define
variations are noted, corrective action shall be taken to estab-
anyspecializedsite-specificsamplingtechniquesorprocedures
lish homogeneity in the material prior to sampling. If it is
that are required to ensure unbiased samples for existing
necessary to indicate the degree of variability existing within
conditions. The owner and supplier shall agree upon the use of
the main pile, separate samples shall be drawn from separate
any specialized site-specific techniques or procedures. When
areas of the pile. The seller shall provide suitable equipment
site-specific techniques or procedures are developed for sam-
needed for proper inspection and sampling.
pling a stockpile, those procedures shall supersede the proce-
5.3 Procedure:
dures given in 5.3.3.1.(Note 6). General principles for sam-
5.3.1 Sampling from a Flowing Aggregate Stream (Bins or pling from stockpiles are applicable to sampling from trucks,
rail cars, barges, or other transportation units.
Belt Discharge)—Select units to be sampled by a random
method, such as Practice D3665, from the production. Obtain
NOTE 6—Specific site sampling plans may include the number of
at least three approximately equal increments, selected at
sampling increments (loader buckets) required to construct the sampling
random from the unit being sampled, and combine to form a
pad.
field sample whose mass equals or exceeds the minimum
5.3.3.1 Sampling from Stockpiles with Power Equipment
recommended in 5.4.2. Take each increment from the entire
(preferred)—In sampling material from stockpiles it is very
cross section of the material as it is being discharged. It is
difficult to ensure unbiased samples due to the segregation
usually necessary to have a special device constructed for use
at each particular plant. This device consists of a pan of
sufficient size to intercept the entire cross section of the
discharge stream and hold the required quantity of material
without overflowing.Aset of rails may be necessary to support
the pan as it is passed under the discharge stream. Insofar as is
possible, keep bins continuously full or nearly full to reduce
segregation.
NOTE 4—Sampling the initial discharge or the final few tons from a bin
or conveyor belt increases the chances of obtaining segregated material
and should be avoided.
5.3.2 Sampling from the Conveyor Belt—Select units to be
sampled by a random method, such as Practice D3665, from
the production. Obtain at least three approximately equal
increments, selected at random, from the unit being sampled
and combine to form a field sample whose mass equals or
exceeds the minimum recommended in 5.4.2. Stop the con- FIG. 1 Belt Sampling Template
D75/D75M − 19
theentireflatarea,butavoidsamplingwithin0.3m[1ft]ofthe
sample pad edge. Divide the sample pad into four quadrants
and sample equal amounts of materials evenly across each
quadrant. Fully insert the shovel as near vertical as possible
then gently roll the shovel back and lift slowly to avoid coarse
material rolling off the sides of the shovel (Note 7). Obtain
additional shovelfuls from different quadrants of the sampling
pad, and in areas that avoid previous “shovel holes.”
NOTE 7—Square-tip shovels with the outer edges rolled up approxi-
mately 50 mm [2 in.] on each side work well in preventing material from
rolling from the side. Spade-tip shovels are not recommended.
5.3.3.2 Sampling from Stockpiles Without Power Equip-
ment:
NOTE 8—Sampling coarse aggregate and coarse and fine mixed
FIG. 2 Automatic Belt Sampler
aggregate stockpiles without the aid of power equipment is not advised.
(1) Where power equipment is not available, samples from
stockpiles shall be made up of at least three increments taken
which often occurs when material is stockpiled, with coarser
particles rolling to the outside base of the pile. For coarse or from the top third, at the mid-point, and bottom third of the
elevation of the stockpile.
mixed coarse and fine aggregate, every effort shall be made to
enlist the services of power equipment to develop a separate (2) Shove a board vertically into the pile just above the
sampling point to prevent coarser material from rolling down
small sampling pile.
(1) When obtaining a sample from a stockpile for accep- and further segregating the material and biasing the sample.
tance testing, a loader shall enter the stockpile nearest the area The board shall be of ample size to prevent material from
representing material that is currently being shipped or loaded cascading down into the sampling area.
into a production facility, with the bucket approximately (3) With the board in place, scrape off the outermost
150 mm [6 in.] above ground level, never allowing the front surface of the pile with the shovel, then insert the shovel
tires of the loader to ramp up on the pile. Without backing up, perpendicular to the angle of the pile, into the freshly exposed
the loader shall lift the full bucket of material then tilt the material to obtain the sample. Repeat this process across the
bucket down to gently roll the material out of the bucket back face of the stockpile until the recommended minimum field
onto the pile, thus re-blending any segregated material on the sample size in 5.4.2 is obtained but no less than the three
outside surface of the pile. If prior visual inspection noted increments described in 5.3.3.2(1).
discernible variation, or if the loader is not of sufficient size to
5.3.3.3 Sampling Fine Aggregate from Stockpiles (Alterna-
cause a cascading effect down the face of the pile during this
tive Method for Fine Aggregate Only)—When sampling fine
remixing process, several buckets of material shall either be
aggregate from a stockpile, the outer layer, which easily
remixedorremovedanddiscardedtopreventuseofpotentially
becomes segregated by wind and rain during stockpile storage,
injurious material.
shall be removed and the sample taken from the material
(2) After re-blending, the loader shall re-enter the
beneath.
stockpile, as before, and obtain a full loader bucket of the
(1) Sampling tubes approximately 30 mm [1.25 in.] mini-
re-blended material, tilt back, and lift the bucket only high
mumby2m[6ft]in length shall be inserted into the shipping
enough to back up slightly.
face of the stockpile horizontally at random locations.
(3) At the base of the main stockpile with the bucket only
high enough to permit free-flow of the material from the NOTE 9—A sampling tube can be constructed of aluminum, PVC, or
other sturdy material. The tip being inserted into the pile can be cut at a
bucket, the loader operator shall tilt the bucket forward to
45° angle to ease insertion.
gently roll the material out of the bucket, forming a small
(2) Sample shall be taken at a minimum height of 3 ft from
sampling pile. If the loader bucket is not of sufficient size to
the surrounding grade.
create a sample pad of representative size, multiple buckets
(3) A minimum of five tube insertions randomly spaced
shall be used, dumped on top of each other and back-dragged
across the face of the stockpile shall form a single field sample
to form a single sample pad.
(see Fig. 4). Ensur
...

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: D75/D75M − 14 D75/D75M − 19 American Association State
Highway and Transportation
Officials Standard
AASHTO No.: T2
Standard Practice for
Sampling Aggregates
This standard is issued under the fixed designation D75/D75M; 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 Scope*
1.1 This practice covers sampling of coarse and fine aggregates for the following purposes:
1.1.1 Preliminary investigation of the potential source of supply,
1.1.2 Control of the product at the source of supply,
1.1.3 Control of the operations at the site of use, and
1.1.4 Acceptance or rejection of the materials.
NOTE 1—Sampling plans and acceptance and control tests vary with the type of construction in which the material is used.
1.2 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes
(excluding those in tables and figures) shall not be considered as requirements of the standard.
1.3 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 non-conformancenonconformance with the standard.
NOTE 2—The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the
capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of Specification D3666 are generally considered capable
of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Specification D3666 alone does
not completely ensure reliable results. Reliable results depend on many factors; following the suggestions of Specification D3666 or some similar
acceptable guideline provides a means of evaluating and controlling some of those factors.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
NOTE 2—The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the
capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of Practice D3666 are generally considered capable of
competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3666 alone does not
completely assure reliable results. Reliable results depend on many factors; following the suggestions of Practice D3666 or some similar acceptable
guideline provides a means of evaluating and controlling some of those factors.
1.5 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:
C125 Terminology Relating to Concrete and Concrete Aggregates
C702C702/C702M Practice for Reducing Samples of Aggregate to Testing Size
D8 Terminology Relating to Materials for Roads and Pavements
D2234/D2234M Practice for Collection of a Gross Sample of Coal
This practice is under the jurisdiction of ASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.30 on Methods of
Sampling.
Current edition approved June 1, 2014Nov. 1, 2019. Published June 2014November 2019. Originally approved in 1920. Last previous edition approved in 20092014 as
D75/D75M – 09.D75/D75M – 14. DOI: 10.1520/D0075_D0075M-14.10.1520/D0075_D0075M-19.
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.
*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
D75/D75M − 19
D3665 Practice for Random Sampling of Construction Materials
D3666 Specification for Minimum Requirements for Agencies Testing and Inspecting Road and Paving Materials
E105 Practice for Probability Sampling of Materials
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or
Process
E141 Practice for Acceptance of Evidence Based on the Results of Probability Sampling
3. Terminology
3.1 Definitions:
3.1.1 maximum size of aggregate, n—in specifications for, or descriptions of aggregate—the smallest sieve opening through
which the entire amount of aggregate is required to pass.
3.1.2 maximum aggregate size, (Superpave) n—in specifications for, or descriptions of aggregate—one size larger than the
nominal maximum aggregate size.
3.1.3 nominal maximum aggregate size (of aggregate), n—in specifications for, or descriptions of aggregate—the smallest sieve
opening through which the entire amount of the aggregate is permitted to pass.
3.1.4 nominal maximum aggregate size (Superpave), n—in specifications for, or descriptions of aggregate—one size larger than
the first sieve that retains more than 10 % aggregate.
3.1.4.1 Discussion—
The definitions in 3.1.1 and 3.1.2 also appear in Terminologies C125 and D8. They are presented in this standard to illustrate the
differences between the aggregate definitions and Superpave definitions of similar terms. The definitions in 3.1.2 and 3.1.4 apply
to hot mix asphalt (HMA) mixtures designed using the Superpave system only.
3.1.4.2 Discussion—
Specifications on aggregates usually stipulate a sieve opening through which all of the aggregate may, but not need to, pass so that
a slated maximum portion of the aggregate may be retained on that sieve. A sieve opening so designed is the nominal maximum
size.
3.1 Definitions—For definitions of terms used in this practice, refer to Terminology D8.
4. Significance and Use
4.1 Sampling is equally as important as the testing, and the sampler shall use every precaution to obtain samples that will show
the nature and condition of the materials which they represent.
4.2 Samples for preliminary investigation tests are obtained by the party responsible for development of the potential source
(Note 3). Samples of materials for control of the production at the source or control of the work at the site of use are obtained by
the manufacturer, contractor, or other parties responsible for accomplishing the work. Samples for tests to be used in acceptance
or rejection decisions by the purchaser are obtained by the purchaser or his authorized representative.
NOTE 3—The preliminary investigation and sampling of potential aggregate sources and types occupies a very important place in determining the
availability and suitability of the largest single constituent entering into the construction. It influences the type of construction from the standpoint of
economics and governs the necessary material control to ensure durability of the resulting structure, from the aggregate standpoint. This investigation
should be done only by a responsible trainedresponsible, trained, and experienced person. For more comprehensive guidance, see the Appendix.appen-
dixes.
5. Securing Samples
5.1 General—Where practicable, samples to be tested for quality shall be obtained from the finished product. Samples from the
finished product to be tested for abrasion loss shall not be subject to further crushing or manual reduction in particle size in
preparation for the abrasion test unless the size of the finished product is such that it requires further reduction for testing purposes.
5.2 Inspection—The material to be sampled shall be visually inspected to determine discernible variations. If any discernible
variations are noted, corrective action shall be taken to establish homogeneity in the material prior to sampling. If it is necessary
to indicate the degree of variability existing within the main pile, separate samples shall be drawn from separate areas of the pile.
The seller shall provide suitable equipment needed for proper inspection and sampling.
5.3 Procedure:
5.3.1 Sampling from a Flowing Aggregate Stream (Bins or Belt Discharge)—Select units to be sampled by a random method,
such as Practice D3665, from the production. Obtain at least three approximately equal increments, selected at random from the
unit being sampled, and combine to form a field sample whose mass equals or exceeds the minimum recommended in 5.4.2. Take
D75/D75M − 19
each increment from the entire cross section of the material as it is being discharged. It is usually necessary to have a special device
constructed for use at each particular plant. This device consists of a pan of sufficient size to intercept the entire cross section of
the discharge stream and hold the required quantity of material without overflowing. A set of rails may be necessary to support
the pan as it is passed under the discharge stream. Insofar as is possible, keep bins continuously full or nearly full to reduce
segregation.
NOTE 4—Sampling the initial discharge or the final few tons from a bin or conveyor belt increases the chances of obtaining segregated material and
should be avoided.
5.3.2 Sampling from the Conveyor Belt—Select units to be sampled by a random method, such as Practice D3665, from the
production. Obtain at least three approximately equal increments, selected at random, from the unit being sampled and combine
to form a field sample whose mass equals or exceeds the minimum recommended in 5.4.2. Stop the conveyor belt while the sample
increments are being obtained. Insert two templates, the shape of which conforms to the shape of the belt in the aggregate stream
on the belt, and space them such that the material contained between them will yield an increment of the required weight (see Fig.
1). Carefully scoop all material between the templates into a suitable container and collect the fines on the belt with a brush and
dust pan and add to the container.
NOTE 5—Automatic belt samplers may be used as long as they are properly maintained, and regular inspection ensures all material is being removed
from the belt (see Fig. 2).
5.3.3 Sampling from Stockpiles—Avoid sampling coarse aggregate or mixed coarse and fine aggregate from stockpiles whenever
possible, particularly when the sampling is done for the purpose of determining aggregate properties that may be dependent upon
the grading of the sample. If circumstances make it necessary to obtain samples from a stockpile of coarse aggregate or a stockpile
of combined coarse and fine aggregate, design a sampling plan for the specific case under consideration to ensure that segregation
does not introduce a bias in the results. This approach will allow the sampling agency to use a sampling plan that will give a
confidence in results obtained therefrom that is agreed upon by all parties concerned to be acceptable for the particular situation.
The sampling plan shall define the number of samples necessary to represent lots and sublots of specific sizes. The sampling plan
shall also define any specialized site-specific sampling techniques or procedures that are required to ensure unbiased samples for
existing conditions. The owner and supplier shall agree upon the use of any specialized site-specific techniques or procedures.
When site-specific techniques or procedures are developed for sampling a stockpile, those procedures shall supersede the
procedures given in 5.3.3.1. (Note 6). General principles for sampling from stockpiles are applicable to sampling from trucks, rail
cars, barges, or other transportation units.
NOTE 6—Specific site sampling plans may include the number of sampling increments (loader buckets) required to construct the sampling pad.
5.3.3.1 Sampling from Stockpiles with Power Equipment (preferred)—In sampling material from stockpiles it is very difficult
to ensure unbiased samples due to the segregation which often occurs when material is stockpiled, with coarser particles rolling
to the outside base of the pile. For coarse or mixed coarse and fine aggregate, every effort shall be made to enlist the services of
power equipment to develop a separate small sampling pile.
(1) When obtaining a sample from a stockpile for acceptance testing, a loader shall enter the stockpile nearest the area
representing material that is currently being shipped or loaded into a production facility, with the bucket approximately 150 mm
150 mm [6 in.] above ground level, never allowing the front tires of the loader to ramp up on the pile. Without backing up, the
loader shall lift the full bucket of material then tilt the bucket down to gently roll the material out of the bucket back onto the pile,
thus re-blending any segregated material on the outside surface of the pile. If prior visual inspection noted discernible variation,
or if the loader is not of sufficient size to cause a cascading effect down the face of the pile during this remixing process, several
buckets of material shall either be remixed or removed and discarded to prevent use of potentially injurious material.
FIG. 1 Belt Sampling Template
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FIG. 2 Automatic Belt Sampler
(2) After re-blending, the loader shall re-enter the stockpile, as before, and obtain a full loader bucket of the re-blended
material, tilt back, and lift the bucket only high enough to back up slightly.
(3) At the base of the main stockpile with the bucket only high enough to permit free-flow of the material from the bucket,
the loader operator shall tilt the bucket forward to gently roll the material out of the bucket, forming a small sampling pile. If the
loader bucket is not of sufficient size to create a sample pad of representative size, multiple buckets shall be used, dumped on top
of each other and back-dragged to form a single sample pad.
(4) At this point the loader operator shall raise the bucket, drive forward far enough to reach across the small pile with the
loader bucket without allowing the loader tires to ramp up on the sampling pile, lower the bucket to about half the height of the
small pile, and backup, therefore creating a flat surface for sampling (see Fig. 3). The loader shall only back-drag the small pile
once. This flat surface provides a stable and safe area to obtain a representative sample.
(5) Place the sample bucket(s) near the center of the flat, oval-shaped sampling pad. The sample shall be obtained across the
entire flat area, but avoid sampling within 0.3 m [1 ft] of the sample pad edge. Divide the sample pad into 4four quadrants and
sample equal amounts of materials evenly across each quadrant. Fully insert the shovel as near vertical as possible then gently roll
the shovel back and lift slowly to avoid coarse material rolling off the sides of the shovel (Note 7). Obtain additional shovelfuls
from different quadrants of the sampling pad, and in areas that avoid previous “shovel holes.”
NOTE 7—Square-tip shovels with the outer edges rolled up approximately 50 mm [2 in.] on each side workswork well in preventing material from
rolling from the side. Spade-tip shovels are not recommended.
5.3.3.2 Sampling from Stockpiles Without Power Equipment:
NOTE 8—Sampling coarse aggregate and coarse and fine mixed aggregate stockpiles without the aid of power equipment is not advised.
(1) Where power equipment is not available, samples
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