ASTM C1550-20

Standard Test Method for Flexural Toughness of Fiber Reinforced Concrete (Using Centrally Loaded Round Panel)

SIGNIFICANCE AND USE
5.1 The post-crack behavior of plate-like, fiber-reinforced concrete structural members is well represented by a centrally loaded round panel test specimen that is simply supported on three pivots symmetrically arranged around its circumference. Such a test panel experiences bi-axial bending in response to a central point load and exhibits a mode of failure related to the in situ behavior of structures. The post-crack performance of round panels subject to a central point load can be represented by the energy absorbed by the panel up to a specified central deflection. In this test method, the energy absorbed up to a specified central deflection is taken to represent the ability of a fiber-reinforced concrete to redistribute stress following cracking.
Note 1: The use of three pivoted point supports in the test configuration results in determinate out-of-plane reactions prior to cracking, however the support reactions are indeterminate after cracking due to the unknown distribution of flexural resistance along each crack. There is also a change in the load resistance mechanism in the specimen as the test proceeds, starting with predominantly flexural resistance and progressing to tensile membrane action around the center as the imposed deflection is increased. The energy absorbed up to a specified central deflection is related to the toughness of the material but is specific to this specimen configuration because it is also determined by the support conditions and size of the specimen. Selection of the most appropriate central deflection to specify depends on the intended application for the material. The energy absorbed up to 5 mm central deflection is applicable to situations in which the material is required to hold cracks tightly closed at low levels of deformation. Examples include final linings in underground civil structures such as railway tunnels that may be required to remain water-tight. The energy absorbed up to 40 mm is more applicable to situations in ...
SCOPE
1.1 This test method covers the determination of flexural toughness of fiber-reinforced concrete expressed as energy absorption in the post-crack range using a round panel supported on three symmetrically arranged pivots and subjected to a central point load. The performance of specimens tested by this method is quantified in terms of the energy absorbed between the onset of loading and selected values of central deflection.  
1.2 This test method provides for the scaling of results whenever specimens do not comply with the target thickness and diameter, as long as dimensions do not fall outside of given limits.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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: 30-Sep-2020
• ICS: 91.100.40 - Products in fibre-reinforced cement
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.42 - Fiber-Reinforced Concrete

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: C1550 − 20
Standard Test Method for
Flexural Toughness of Fiber Reinforced Concrete (Using
1
Centrally Loaded Round Panel)
This standard is issued under the fixed designation C1550; 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* C125Terminology Relating to Concrete and Concrete Ag-
gregates
1.1 This test method covers the determination of flexural
C670Practice for Preparing Precision and Bias Statements
toughness of fiber-reinforced concrete expressed as energy
for Test Methods for Construction Materials
absorption in the post-crack range using a round panel sup-
portedonthreesymmetricallyarrangedpivotsandsubjectedto
3. Terminology
a central point load. The performance of specimens tested by
3.1 Definitions—For definitions of terms used in this test
this method is quantified in terms of the energy absorbed
method, refer to Terminology C125.
between the onset of loading and selected values of central
deflection.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 central deflection—the net deflection at the center of
1.2 This test method provides for the scaling of results
the panel measured relative to a plane defined by the three
whenever specimens do not comply with the target thickness
pivotsusedtosupportthepanel;thisisaconditioneddeflection
anddiameter,aslongasdimensionsdonotfalloutsideofgiven
that excludes extraneous deformations of the load train and
limits.
local crushing of the panel at the point of load application and
1.3 The values stated in SI units are to be regarded as
points of support.
standard. No other units of measurement are included in this
3.2.2 compliance—a measure of the tendency of a structure
standard.
to deflect under load, found as the inverse of stiffness or
1.4 This standard does not purport to address all of the
deflection divided by the corresponding load.
safety concerns, if any, associated with its use. It is the
3.2.3 load train—those parts of a testing machine that
responsibility of the user of this standard to establish appro-
experience load and undergo straining during a mechanical
priate safety, health, and environmental practices and deter-
test, including the actuator, frame, support fixtures, load cell,
mine the applicability of regulatory limitations prior to use.
and specimen.
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3.2.4 toughness—the energy absorbed by the specimen
ization established in the Decision on Principles for the
equivalent to the area under the load-deflection curve between
Development of International Standards, Guides and Recom-
the onset of loading and a specified central deflection.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 4. Summary of Test Method
4.1 Moldedroundpanelsofcastfiber-reinforcedconcreteor
2. Referenced Documents
fiber-reinforced shotcrete are subjected to a central point load
2
2.1 ASTM Standards:
while supported on three symmetrically arranged pivots. The
C31/C31MPractice for Making and Curing Concrete Test
load is applied through a hemispherical-ended steel piston
Specimens in the Field
advanced at a prescribed rate of displacement. Load and
deflectionarerecordedsimultaneouslyuptoaspecifiedcentral
1 deflection. The energy absorbed by the panel up to a specified
This test method is under the jurisdiction of ASTM Committee C09 on
Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee central deflection is representative of the flexural toughness of
C09.42 on Fiber-Reinforced Concrete.
the fiber-reinforced concrete panel.
Current edition approved Oct. 1, 2020. Published November 2020. Originally
approved in 2002. Last previous edition approved in 2019 as C1550–19. DOI:
5. Significance and Use
10.1520/C1550-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.1 The post-crack behavior of plate-like, fiber-reinforced
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
concrete structural members is well represented by a centrally
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. loaded round panel test specimen that is simply supported on
*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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...

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: C1550 − 19 C1550 − 20
Standard Test Method for
Flexural Toughness of Fiber Reinforced Concrete (Using
1
Centrally Loaded Round Panel)
This standard is issued under the fixed designation C1550; 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 flexural toughness of fiber-reinforced concrete expressed as energy absorption
in the post-crack range using a round panel supported on three symmetrically arranged pivots and subjected to a central point load.
The performance of specimens tested by this method is quantified in terms of the energy absorbed between the onset of loading
and selected values of central deflection.
1.2 This test method provides for the scaling of results whenever specimens do not comply with the target thickness and diameter,
as long as dimensions do not fall outside of given limits.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
2. Referenced Documents
2
2.1 ASTM Standards:
C31/C31M Practice for Making and Curing Concrete Test Specimens in the Field
C125 Terminology Relating to Concrete and Concrete Aggregates
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
3. Terminology
3.1 Definitions—For definitions of terms used in this test method, refer to Terminology C125.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 central deflection—the net deflection at the center of the panel measured relative to a plane defined by the three pivots used
1
This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.42 on
Fiber-Reinforced Concrete.
Current edition approved Oct. 1, 2019Oct. 1, 2020. Published November 2019November 2020. Originally approved in 2002. Last previous edition approved in 20122019
as C1550C1550 – 19.–12a. DOI: 10.1520/C1550-19.10.1520/C1550-20.
2
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

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C1550 − 20
to support the panel; this is a conditioned deflection that excludes extraneous deformations of the load train and local crushing of
the panel at the point of load application and points of support.
3.2.2 compliance—a measure of the tendency of a structure to deflect under load, found as the inverse of stiffness or deflection
divided by the corresponding load.
3.2.3 load train—those parts of a testing machine that experience load and undergo straining during a mechanical test, including
the actuator, frame, support fixtures, load cell, and specimen.
3.2.4 toughness—the energy absorbed by the specimen equivalent to the area under the load-deflection curve between the onset
of loading and a specified central deflection.
4. Summary of Test Method
4.1 Molded round panels of cast fiber-reinforced concrete or fiber-reinforced shotcrete are subjected to a central point load while
supported on three symmetrically arranged pivots. The load is applied through a hemispherical-ended steel piston advanced at a
prescribed rate of displacement. Load and deflection are recorded simultaneously up to a specified central deflection. The energy
absorbed by the panel up to a specified central deflectio
...