ASTM C1451-18

Standard Practice for Determining Variability of Concrete-Making Materials From a Single Source

SIGNIFICANCE AND USE
4.1 This practice provides a systematic procedure for sampling and determining the variability of user-selected properties of concrete-making materials. Results derived from application of the practice are generally intended for information only and are not requirements of any existing ASTM specification on concrete or concrete-making materials. A concrete materials specification may make reference to this practice as a means of obtaining variability information, but needs to define the properties to be measured and the lot size and sample unit to be used. This practice is applicable to both producers and consumers of concrete-making materials, although details of application of the practice may vary, depending on the intended purpose of the user of this practice.  
4.2 The procedure is applicable to any quantitative property of any concrete-making material that can be measured by a standard test method. The procedure is based on grab samples, which will tend to show the maximum amount of variation of the material being evaluated. The procedure is useful if grab samples are obtained from sampling units that are being delivered to the user of a material and better represents the variability of the material used in concrete production than tests performed on the material for specification compliance that are documented on a mill test report or material certification. The procedure was developed for application to materials from a single source, but it can be applied to a materials delivery stream from more than one source, depending on the purposes of the user of the practice. Variations among test results on separate samples within a lot are corrected for testing error, therefore giving an estimate of the variability of the selected material property. The variability of the selected material property provides the user with one indicator of the source variation of the concrete-making material.  
4.3 Although variability in properties of concrete-making materials can...
SCOPE
1.1 This practice covers a procedure for determining the variability of concrete-making materials from a single source by measuring a characteristic property of the material. It includes recommendations on sampling, testing, analysis of data, and reporting.  
1.2 The system of units for this practice is not specified. Units used in examples of calculation methods are for illustration purposes. The calculation methods described in this practice can be used with either SI or inch-pound units.  
1.3 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.  
1.4 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-Dec-2017
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.94 - Evaluation of Data (Joint C09 and C01)

Relations

• Replaces: ASTM C1451-11 - Standard Practice for Determining Uniformity of Ingredients of Concrete From a Single Source
• Effective Date: 01-Jan-2018
• Refers: ASTM C219-24 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2024
• Refers: ASTM C109/C109M-23 - Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens)
• Effective Date: 15-Dec-2023
• Refers: ASTM C219-20a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Aug-2020
• Refers: ASTM C219-20 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2020
• Refers: ASTM C125-19a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2019
• Refers: ASTM C219-19a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 15-Nov-2019
• Refers: ASTM D75/D75M-19 - Standard Practice for Sampling Aggregates
• Effective Date: 01-Nov-2019
• Refers: ASTM C219-19 - Standard Terminology Relating to Hydraulic Cement
• Effective Date: 01-Jun-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 C917/C917M-18 - Standard Test Method for Evaluation of Variability of Cement from a Single Source Based on Strength
• Effective Date: 01-Jan-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

Overview

ASTM C1451-18: Standard Practice for Determining Variability of Concrete-Making Materials From a Single Source provides a systematic approach for assessing the variability of key properties in materials used for concrete production. Developed by ASTM, this practice outlines recommendations for sampling, testing, data analysis, and reporting procedures. It is applicable to both producers and consumers of concrete-making materials and aims to offer valuable variability data for quality control, process optimization, and compliance assessment. While the practice is primarily designed for a single source of material, its methodology can be adapted for materials from multiple sources if needed.

Key Topics

• Sampling Concrete-Making Materials: Includes recommendations for random grab samples from defined sampling units and lots, ensuring a representative assessment of material variability.
• Testing and Analysis: Guidance on choosing appropriate test methods for different material properties, with an emphasis on precision to ensure accuracy in variability assessment.
• Variability Determination: Procedures for differentiating between total variation and testing error to obtain a reliable estimate of single-source variation.
• Reporting Requirements: Specifies how to document all findings, including averages, standard deviations, coefficients of variation, and graphical or tabular presentations of test results.
• Terminology: Standard definitions for terms such as lot, sampling unit, grab sample, and single-source variation, referencing ASTM C125 and ASTM C219 terminology.

Applications

The primary application of ASTM C1451-18 is to inform users about the intrinsic variability of concrete-making materials (such as cement, aggregates, chemical admixtures, pozzolans, and slags) from a single source. Key practical uses include:

• Quality Control: Helps producers monitor the consistency of their materials over time and identify any deviations in properties that could impact concrete performance.
• Performance Optimization: Assists consumers in selecting materials with predictable properties, thus optimizing mix designs and improving finished concrete quality.
• Specification and Compliance Support: Provides informational data that can be referenced in project specifications or material supply agreements to set expectations for consistency.
• Troubleshooting: Helps diagnose causes of fluctuating concrete performance, distinguishing between material variability and other process factors.
• Testing Protocols: Ensures all laboratories performing tests follow a consistent methodology, improving the reliability and comparability of results.

Related Standards

ASTM C1451-18 is often used in conjunction with the following standards for comprehensive materials evaluation and quality management:

• ASTM C109/C109M: Test Method for Compressive Strength of Hydraulic Cement Mortars
• ASTM C125: Terminology Relating to Concrete and Concrete Aggregates
• ASTM C219: Terminology Relating to Hydraulic Cement
• ASTM C494/C494M: Specification for Chemical Admixtures for Concrete
• ASTM C917/C917M: Test Method for Evaluation of Variability of Cement from a Single Source Based on Strength
• ASTM D75/D75M: Practice for Sampling Aggregates
• ASTM D3665: Practice for Random Sampling of Construction Materials

Practical Value

By following ASTM C1451-18, stakeholders in the concrete industry can systematically evaluate and report the variability of material properties, leading to improved quality assurance and reduced risk in concrete construction. The procedures foster greater transparency between material suppliers and end users, support data-driven decisions, and establish a foundation for continual improvement in material supply chains.

Keywords

ASTM C1451-18, concrete-making materials variability, concrete quality control, sampling procedures, testing error, single-source variation, reporting concrete materials, material consistency, ASTM standards for concrete, concrete materials analysis

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: C1451 − 18
Standard Practice for
Determining Variability of Concrete-Making Materials From a
Single Source
This standard is issued under the fixed designation C1451; 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* C917/C917M Test Method for Evaluation of Variability of
Cement from a Single Source Based on Strength
1.1 This practice covers a procedure for determining the
D75/D75M Practice for Sampling Aggregates
variability of concrete-making materials from a single source
D3665 Practice for Random Sampling of Construction Ma-
by measuring a characteristic property of the material. It
terials
includes recommendations on sampling, testing, analysis of
data, and reporting.
3. Terminology
1.2 The system of units for this practice is not specified.
3.1 Definitions:
Units used in examples of calculation methods are for illustra-
3.1.1 Fordefinitionsoftermsrelatingtothispracticereferto
tion purposes. The calculation methods described in this
Terminology C125 and Terminology C219.
practice can be used with either SI or inch-pound units.
3.2 Definitions of Terms Specific to This Standard:
1.3 This standard does not purport to address all of the
3.2.1 grab sample, n—a specified quantity of material ob-
safety concerns, if any, associated with its use. It is the
tained in a single operation from a sampling unit.
responsibility of the user of this standard to establish appro-
3.2.1.1 Discussion—The goal of procuring a grab sample is
priate safety, health, and environmental practices and deter-
to obtain a small portion of material that is representative of
mine the applicability of regulatory limitations prior to use.
that in the sampling unit.
1.4 This international standard was developed in accor-
3.2.2 lot, n—a user-defined quantity, representing the
dance with internationally recognized principles on standard-
amount of material for which variability information is to be
ization established in the Decision on Principles for the
determined.
Development of International Standards, Guides and Recom-
3.2.2.1 Discussion—The minimum lot size is defined by a
mendations issued by the World Trade Organization Technical
userandcanbethetotalamountofmaterialinaproductionrun
Barriers to Trade (TBT) Committee.
where manufacturing conditions are unchanged or as the
amount of material produced over a given interval of time.
2. Referenced Documents
3.2.3 sampling unit, n—amount of material from which a
2.1 ASTM Standards:
grab sample is taken.
C109/C109M Test Method for Compressive Strength of
3.2.3.1 Discussion—Generally a lot is subdivided into sam-
Hydraulic Cement Mortars (Using 2-in. or [50-mm] Cube
pling units, and then sampling units are chosen at random for
Specimens)
taking of grab samples. The size of the sampling unit is
C125 Terminology Relating to Concrete and Concrete Ag-
user-defined, depending on the purposes of the evaluation. The
gregates
sampling unit is often the amount of material in a single
C219 Terminology Relating to Hydraulic Cement
conveyance to the concrete producer, such as a delivery truck,
C494/C494M Specification for Chemical Admixtures for
rail-car, or barge. The term sublot is sometimes used as an
Concrete
alternative for sampling unit.
4. Significance and Use
This practice is under the jurisdiction of ASTM Committee C09 on Concrete
andConcreteAggregatesandisthedirectresponsibilityofSubcommitteeC09.94on
4.1 This practice provides a systematic procedure for sam-
Evaluation of Data (Joint C09 and C01).
pling and determining the variability of user-selected proper-
Current edition approved Jan. 1, 2018. Published February 2018. Originally
ties of concrete-making materials. Results derived from appli-
approved in 1999. Last previous edition approved in 2011 as C1451–11. DOI:
10.1520/C1451-18.
cation of the practice are generally intended for information
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
only and are not requirements of any existing ASTM specifi-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
cation on concrete or concrete-making materials. A concrete
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. materials specification may make reference to this practice as
*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
C1451 − 18
a means of obtaining variability information, but needs to a relatively intense sampling plan might be designed initially.
definethepropertiestobemeasuredandthelotsizeandsample If prior knowledge indicates that the material is relatively
unit to be used. This practice is applicable to both producers uniform, then a less intense sampling plan might be designed.
and consumers of concrete-making materials, although details
5.3 The second step is to define the size of the lot and the
of application of the practice may vary, depending on the
size of the sampling unit (see 3.2). Typically a lot is divided
intended purpose of the user of this practice.
into a number of sampling units; then sampling units are
4.2 The procedure is applicable to any quantitative property selected at random for the taking of grab samples. Typically,
the number of sampling units is larger than the number of
of any concrete-making material that can be measured by a
standard test method. The procedure is based on grab samples, samples obtained, although for small lot sizes, the number of
sampling units may equal the number of samples being taken.
which will tend to show the maximum amount of variation of
the material being evaluated. The procedure is useful if grab Alternatively, sampling may be on a time-based frequency.
samples are obtained from sampling units that are being
5.4 Take random grab samples from a point in the storage
delivered to the user of a material and better represents the
and handling process of the material that will accurately reflect
variability of the material used in concrete production than
the variability of the material as it will be used in concrete.
tests performed on the material for specification compliance
Practice D3665 provides general guidance. Additional guid-
that are documented on a mill test report or material certifica-
ance for specific materials is listed in 5.4.1 – 5.4.4. Identify
tion. The procedure was developed for application to materials
samples by the date on which the material was shipped or
from a single source, but it can be applied to a materials
received, its source, and designated type and applicable speci-
delivery stream from more than one source, depending on the
fications.
purposes of the user of the practice. Variations among test
5.4.1 SamplecementinaccordancewithTestMethodC917/
resultsonseparatesampleswithinalotarecorrectedfortesting
C917M.
error, therefore giving an estimate of the variability of the
5.4.2 Sample fine and coarse aggregates in accordance with
selected material property. The variability of the selected
Practice D75/D75M.
material property provides the user with one indicator of the
5.4.3 Sample chemical admixtures in accordance with
source variation of the concrete-making material.
Specification C494/C494M.
4.3 Although variability in properties of concrete-making 5.4.4 Sample pozzolan or slag cement in accordance with
materials can be a significant cause of variability in concrete
Test Method C917/C917M.
properties,thispracticedoesnotpurporttogiveinformationon
this relationship. This practice does give information on
6. Procedure
variability of concrete-making materials from which the user
6.1 Total Variation—Test all samples in accordance with the
can, along with supplementary information or correlative
appropriate ASTM Test Method for the particular property
testingofconcreteproperties,developquantitativeestimatesof
being measured. Choose a property that is expected to have a
the effects.
significant influence on concrete performance, and choose a
test method that has good precision so that the material
5. Sampling
variability is not masked by the testing error. It is also
5.1 The sampling plan underlying the analysis of variability advisable to select a method that does not incur significant cost
iscriticaltotheinterpretationofresults.Thesamplingplanwill and is conducted frequently so the operators are proficient with
vary, depending on the details of concrete-making materials the procedure. Variation within a single source is estimated by
supply and user-defined purpose of the evaluation. The sam- first calculating total variation from test data on grab samples,
pling plan should, at a minimum, address the lot size and and then correcting this by subtracting variation inherent in the
sampling frequency, location and procedure of sampling from test method (testing error). Best results are obtained if all tests
sampling unit, and handling of samples.The required sampling are conducted in the same laboratory, but guidance is provided
frequency depends on how the data are being used and the if it is necessary to use data from more than one laboratory.
nature of the material being evaluated. All sampling is to be Calculate the total variation among the samples, as directed in
performed by personnel specifically trained for this purpose. 7.1.3. The total variation includes testing error.
The sampling plan should be described in the report (Section
6.2 Testing Error—Testing error comprises components due
8).
to within-laboratory variation and between-laboratory varia-
tion. If results are obtained from only one laboratory, then
5.2 The first step in defining the sampling plan is to
establish the objective and scope of the evaluation. This between-laboratoryvariationmakesnocontribution.Ifdataare
obtainedfrommorethanonelaboratory,itispreferabletokeep
requires considerable experience and knowledge of details
involved with the particular production under evaluation. The data from each one separate during data analysis, pooling
estimates of variation at the end of the analysis.
objective and scope of the evaluation may vary between users
and producers of materials. It may also range from determining 6.2.1 To estimate within-laboratory testing error, duplicate
the variability of materials during a relatively small production tests made from a single sample are required. Grab samples
period to covering a very long production period. If there is no from separate sampling units must be tested in duplicate until
prior knowledge of the variability of a material, or if it is results of at least ten duplicate tests are obtained. The fre-
suspected that the material might show considerable variation, quencyofduplicatetestsinitiallyshouldbeatleastonceinfive
C1451 − 18
samples and not less frequently than once per month. Calculate where:
the testing error stan
...

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: C1451 − 11 C1451 − 18
Standard Practice for
Determining Variability of Ingredients of Concrete Concrete-
Making Materials From a Single Source
This standard is issued under the fixed designation C1451; 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 covers a procedure for determining the variability of properties of concrete concrete-making materials from
a single source. source by measuring a characteristic property of the material. It includes recommendations on sampling, testing,
analysis of data, and reporting.
1.2 The system of units for this practice is not specified. Dimensional quantities in the practice are presented only as illustrations
Units used in examples of calculation methods that are applicable independent of the system of are for illustration purposes. The
calculation methods described in this practice can be used with either SI or inch-pound units.
1.3 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.
1.4 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:
C109/C109M Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or [50-mm] Cube Specimens)
C125 Terminology Relating to Concrete and Concrete Aggregates
C219 Terminology Relating to Hydraulic Cement
C494/C494M Specification for Chemical Admixtures for Concrete
C917C917/C917M Test Method for Evaluation of Variability of Cement from a Single Source Based on Strength
D75D75/D75M Practice for Sampling Aggregates
D3665 Practice for Random Sampling of Construction Materials
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms relating to this practice refer to Terminology C125 and Terminology C219.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 grab sample, n—a specified quantity of material obtained in a single operation from a sampling unit.
3.2.1.1 Discussion—
The goal of procuring a grab sample is to obtain a small portion of material that is characteristicrepresentative of that in the
sampling unit.
3.2.2 lot, n—a user-defined quantity, typically representing anythe amount of material for which variability information is to be
calculated.determined.
This practice is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.94 on
Evaluation of Data (Joint C09 and C01).
Current edition approved July 1, 2011Jan. 1, 2018. Published August 2011February 2018. Originally approved in 1999. Last previous edition approved in 20052011 as
C1451–05.–11. DOI: 10.1520/C1451-11.10.1520/C1451-18.
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
C1451 − 18
3.2.2.1 Discussion—
The minimum lot size is generally the amount of material in a single conveyance, such as a truck load, a rail-car load, or a barge
load. At the other extreme, a lot might be defined by a user as and can be the total amount of material used in a single construction
or by a supplier in a production run where manufacturing conditions are unchanged or as the amount of material produced over
a given interval of time.
3.2.3 sampling unit, n—amount of material from which a grab sample is taken.
3.2.3.1 Discussion—
Generally a lot is subdivided into sampling units, and then sampling units are chosen at random for taking of grab samples. The
size of the sampling unit is user-defined, depending on the purposes of the evaluation. The sampling unit is often the amount of
material in a single conveyance to the concrete producer, such as a delivery truck, rail-car, or barge. The term sub lotsublot is
sometimes used to define this concept.as an alternative for sampling unit.
4. Significance and Use
4.1 This practice provides a systematic procedure for sampling and determining the variability of user-selected properties of
ingredients of concrete. concrete-making materials. Results derived from application of the practice are generally intended for
information only and are not requirements of any existing ASTM specification on concrete or concreteconcrete-making materials.
A concrete materials specification may make reference to this practice as a means of obtaining variability information, but needs
to define the properties to be measured and the lot size and sample unit to be used. TheThis practice is applicable to both producers
of concrete materials and to and consumers of concreteconcrete-making materials, although details of application of the practice
may vary, depending on the intended purpose of the user of thethis practice.
4.2 The procedure is applicable to any quantitative property of any concrete ingredientconcrete-making material that can be
measured by a standard test method. The procedure is based on grab samples, which will tend to show the maximum amount of
variation inof the selected material property. being evaluated. The procedure is useful if grab samples are obtained from sampling
units that are being delivered to the user of a material and better represents the variability of the material used in concrete
production compared with testingthan tests performed on the material for specification compliance. compliance that are
documented on a mill test report or material certification. The procedure was developed for application to materials from a single
source, but it can be applied to a materials delivery stream from more than one source, depending on the purposes of the user of
the practice. Variations among test results on separate samples within a lot are corrected for testing error, therefore giving an
estimate of the variability of the selected material property. The variability of the selected material property provides the user with
one indicator of the source variation of the concrete ingredient.concrete-making material.
4.3 Although variability in properties of concreteconcrete-making materials can be a significant cause of variability in concrete
properties, this practice does not purport to give information on this relationship. This practice does give information on variability
of ingredients concrete-making materials from which the user can, along with supplementary information or correlative testing of
concrete properties, develop quantitative estimates of the effects.
5. Sampling
5.1 The sampling plan underlying the analysis of variability is critical to the interpretation of results. The sampling plan will
vary, depending on the details of concreteconcrete-making materials supply and user-defined purpose of the evaluation. The
sampling plan should, at a minimum, address the lot size and sampling frequency, location and procedure of sampling from
sampling unit, and handling of samples. The required sampling frequency depends on how the data are being used and the nature
of the material being evaluated. All sampling is to be performed by personnel specifically trained for this purpose. The sampling
plan should be described in the report (Section 8).
5.2 The first step in determiningdefining the sampling plan is to defineestablish the objective and scope of the evaluation. This
requires considerable experience and knowledge of details involved with the particular production under evaluation. The objective
and scope of the evaluation may vary between users and producers of materials. It may also range from determining the variability
of materials during a relatively small production period to covering a very long production period. If there is no prior knowledge
of the variability of a material property, material, or if it is suspected that the material might show considerable variation, a
relatively intense sampling plan might be designed initially. If prior knowledge indicates that the material property is relatively
stable,uniform, then a less intense sampling plan might be designed.
5.3 The second step is to define the size of the lot and the size of the sampling unit (see 3.2). Typically a lot is divided into a
number of sampling units; then sampling units are selected at random for the taking of grab samples. Typically, the number of
sampling units is larger than the number actually sampled, of samples obtained, although for small lot sizes, the number of
sampling units may equal the number of samples being taken. Alternatively, sampling may be performed on a time-based
frequency.
C1451 − 18
5.4 Take random grab samples from a point in the storage and handling process of the material that will accurately reflect the
variability of the material as it will be used in concrete. Practice D3665 provides general guidance. Additional guidance for specific
materials is listed in 5.4.1 – 5.4.4. Identify samples by the date on which the material was shipped or received, its source, and
designated type and applicable specifications.
5.4.1 Sample cement in accordance with Test Method C917C917/C917M.
5.4.2 Sample fine and coarse aggregates in accordance with Practice D75D75/D75M.
5.4.3 Sample chemical admixtures in accordance with Specification C494/C494M.
5.4.4 Sample pozzolan or slag cement in accordance with Test Method C917C917/C917M.
6. Procedure
6.1 Total Variation—Test all samples in accordance with the appropriate ASTM Test Method for the particular property being
measured. Choose a property that is expected to have a significant influence on concrete performance, and choose a test method
that has good precision so that the material variability is not masked by the testing error. It is also advisable to select a method
that does not incur significant cost and is conducted frequently so the operators are proficient with the procedure. Variation within
a single source is estimated by first calculating total variation from test data on grab samples, and then correcting this by subtracting
variation inherent in the test method (testing error). Best results are obtained if all tests are conducted in the same laboratory, but
guidance is provided if it is necessary to use data from more than one laboratory. Calculate the total variation among the samples,
as directed in 7.1.3. The total variation includes testing error.
6.2 Testing Error—Testing error comprises components due to within-laboratory variation and between-laboratory variation. If
results are obtained from only one laboratory, then between-laboratory variation makes no contribution. If data are obtained from
more than one laboratory, it is preferable to keep data from each one separate during data analysis, pooling estimates of variation
at the end of the analysis.
6.2.1 To estimate within-laboratory testing error, duplicate tests made from a single sample are required. Samples from different
days Grab samples from separate sampling units must be tested in duplicate until results of at least ten samples have been tested
in duplicate. duplicate tests are obtained. The frequency of duplicate tests initially should be a
...