ASTM C348-20

Standard Test Method for Flexural Strength of Hydraulic-Cement Mortars

SIGNIFICANCE AND USE
5.1 This test method provides a means for determining the flexural strength of hydraulic cement mortars. Portions of the mortar prisms tested in flexure in accordance with this test method may be used for the determination of compressive strength in accordance with Test Method C349.  
5.2 The values are determined from this test method for research or reference purposes only and are not used for determining compliance with specification requirements.
SCOPE
1.1 This test method covers the determination of the flexural strength of hydraulic-cement mortars.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 Values in SI units shall be obtained by measurement in SI units or by appropriate conversion, using the Rules for Conversion and rounding given in IEEE/ASTM SI 10, of measurements made in other units.  
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. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.2)  
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: Historical
• Publication Date: 31-Mar-2020
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C01 - Cement
• Drafting Committee: C01.27 - Strength

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C348 − 20
Standard Test Method for
1
Flexural Strength of Hydraulic-Cement Mortars
This standard is issued under the fixed designation C348; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* C219Terminology Relating to Hydraulic and Other Inor-
ganic Cements
1.1 Thistestmethodcoversthedeterminationoftheflexural
C230/C230MSpecification for Flow Table for Use in Tests
strength of hydraulic-cement mortars.
of Hydraulic Cement
1.2 The values stated in SI units are to be regarded as
C305Practice for Mechanical Mixing of Hydraulic Cement
standard. No other units of measurement are included in this
Pastes and Mortars of Plastic Consistency
standard.
C349Test Method for Compressive Strength of Hydraulic-
Cement Mortars (Using Portions of Prisms Broken in
1.3 Values in SI units shall be obtained by measurement in
SI units or by appropriate conversion, using the Rules for Flexure)
C670Practice for Preparing Precision and Bias Statements
Conversion and rounding given in IEEE/ASTM SI 10,of
measurements made in other units. for Test Methods for Construction Materials
C778Specification for Standard Sand
1.4 This standard does not purport to address all of the
C1005Specification for Reference Masses and Devices for
safety concerns, if any, associated with its use. It is the
Determining Mass and Volume for Use in the Physical
responsibility of the user of this standard to establish appro-
Testing of Hydraulic Cements
priate safety, health, and environmental practices and deter-
C1437Test Method for Flow of Hydraulic Cement Mortar
mine the applicability of regulatory limitations prior to use.
IEEE/ASTM SI 10Standard for Use of the International
(Warning—Fresh hydraulic cementitious mixtures are caustic
System of Units (SI): The Modern Metric System
and may cause chemical burns to skin and tissue upon
2
prolonged exposure. )
3. Terminology
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard- 3.1 Definitions:
ization established in the Decision on Principles for the 3.1.1 For definitions of terms used in this test method, refer
Development of International Standards, Guides and Recom- to Terminology C125 and C219.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 4. Summary of Test Method
4.1 The test mortar used consists of one part cement and
2. Referenced Documents
2.75 parts of sand proportion by mass. Portland or air-
3
2.1 ASTM Standards:
entraining portland cements are mixed at specified water-
C109/C109MTest Method for Compressive Strength of
cement ratios. Water content of other cements is that sufficient
Hydraulic Cement Mortars (Using 2-in. or [50-mm] Cube
to obtain a flow of 110 6 5% with 25 drops of the flow table.
Specimens)
Test prisms, 40 by 40 by 160mm, are molded by tamping in
C125Terminology Relating to Concrete and Concrete Ag-
two layers. Prisms are cured one day in the molds and stripped
gregates
until tested by center point loading.
5. Significance and Use
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC01onCement
5.1 This test method provides a means for determining the
and is the direct responsibility of Subcommittee C01.27 on Strength.
flexural strength of hydraulic cement mortars. Portions of the
Current edition approved April 1, 2020. Published April 2020. Originally
approved in 1954. Last previous edition approved in 2019 as C348–19. DOI:
mortar prisms tested in flexure in accordance with this test
10.1520/C0348-20.
method may be used for the determination of compressive
2
See the section on Safety, Manual of Cement Testing, Annual Book of ASTM
strength in accordance with Test Method C349.
Standards, Vol 04.01.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.2 The values are determined from this test method for
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
research or reference purposes only and are not used for
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. determining compliance with specification requirements.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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C348 − 20
6. Apparatus 6.6 Tamper Guide—The tamper guide (see Fig. 2) shall be
made of metal (such as brass of Rockwell hardness not less
6.1 Weights, Weighing Devices, and Glass Graduates—
thanHRB55)notattackedbythece
...

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: C348 − 19 C348 − 20
Standard Test Method for
1
Flexural Strength of Hydraulic-Cement Mortars
This standard is issued under the fixed designation C348; 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 covers the determination of the flexural strength of hydraulic-cement mortars.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 Values in SI units shall be obtained by measurement in SI units or by appropriate conversion, using the Rules for Conversion
and rounding given in Standard IEEE/ASTM SI 10, of measurements made in other units.
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. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns
2
to skin and tissue upon prolonged exposure. )
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
3
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 and Other Inorganic Cements
C230/C230M Specification for Flow Table for Use in Tests of Hydraulic Cement
C305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency
C349 Test Method for Compressive Strength of Hydraulic-Cement Mortars (Using Portions of Prisms Broken in Flexure)
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
C778 Specification for Standard Sand
C1005 Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing of
Hydraulic Cements
C1437 Test Method for Flow of Hydraulic Cement Mortar
IEEE/ASTM SI 10 Standard for Use of the International System of Units (SI): The Modern Metric System
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology C125 and C219.
4. Summary of Test Method
4.1 The test mortar used consists of 1one part cement and 2.75 parts of sand proportion by mass. Portland or air-entraining
portland cements are mixed at specified water-cement ratios. Water content of other cements is that sufficient to obtain a flow of
110 6 5 % with 25 drops of the flow table. Test prisms, 40 by 40 by 160-mm,160 mm, are molded by tamping in two layers. Prisms
are cured one day in the molds and stripped until tested by center point loading.
1
This test method is under the jurisdiction of ASTM Committee C01 on Cement and is the direct responsibility of Subcommittee C01.27 on Strength.
Current edition approved Oct. 1, 2019April 1, 2020. Published November 2019April 2020. Originally approved in 1954. Last previous edition approved in 20182019 as
C348 – 18.C348 – 19. DOI: 10.1520/C0348-19.10.1520/C0348-20.
2
See the section on Safety, Manual of Cement Testing, Annual Book of ASTM Standards, Vol 04.01.
3
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
1

---------------------- Page: 1 ----------------------
C348 − 20
5. Significance and Use
5.1 This test method provides a means for determining the flexural strength of hydraulic cement mortars. Portions of the mortar
prisms tested in flexure according to in accordance with this test method may be used for the determination of compressive strength
in accordance wi
...