ASTM E2923-13
(Practice)Standard Practice for Longevity Assessment of Firestop Materials Using Differential Scanning Calorimetry
Standard Practice for Longevity Assessment of Firestop Materials Using Differential Scanning Calorimetry
SIGNIFICANCE AND USE
5.1 Firestop systems are exposed to fire tests and classified using materials that have been, in all likelihood, quite recently manufactured. The testing provides a fire resistance rating for the firestop system that is measured in hours. The goal of firestop system testing is to identify and list firestop systems that will have a fire resistance rating that is no less than the fire resistance rating of the classified wall or floor assembly in which it is installed. A building fire that could put the firestop system to the test can occur at any time during the life of the building. By that time, the firestop system is composed of materials that have aged. Some assurance is desired to establish quantitatively that the firestop system will continue to have a fire resistance rating that is no less than that of the wall or floor assembly.
5.2 This practice provides one method for examining whether any changes are to be expected in the characteristics of a firestop material during its design life, as gauged by any chemical reactions that occur within the material to change it. The measurement of conversion rate provides a standard measure of how much a material will change over its design life. This provides an objective indication of whether the bulk of the material is likely to exhibit the desirable properties for which it was chosen in the firestop system.
5.3 Measurement of conversion rate allows different firestop materials used for similar purposes to be compared with respect to their ability to remain unchanged during their design life.
5.3.1 This allows materials with an unusually high conversion rate to be questioned and possibly rejected early on during the research and development process.
5.3.2 This allows materials to be screened by testing and listing agencies to ensure that they do not provide a listing for products that are not likely to have adequate performance for the full length of the intended design life.
5.3.3 This allows formulation...
SCOPE
1.1 This practice covers a standardized procedure for quantitatively assessing the longevity of materials used in firestop systems, by the use of data obtained from differential scanning calorimetry.
1.2 This practice is intended to differentiate firestop materials that are expected to maintain performance characteristics over time from those that are expected to degrade in performance characteristics over time. DSC experimental curve evaluation can also deliver indifferent results, where an interpretation of sample properties is not possible without additional testing using conventional durability testing. It evaluates the extent of chemical reactions that will occur within the firestop material under specified conditions of temperature and humidity. This practice does not measure longevity under specific severe environmental conditions or building operation that might be experienced by an individual firestop system.
1.3 This practice is intended to be used to test the materials used within a firestopping system. The practice is not intended to be used to test the properties of assembled firestopping systems.
1.4 This practice is intended to evaluate the following types of materials used in through-penetration fire stops:
1.4.1 Endothermic,
1.4.2 Intumescent,
1.4.3 Insulation,
1.4.4 Ablatives, and
1.4.5 Subliming.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Some specific hazards are given in Section 8 on Hazards.
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Designation: E2923 − 13
StandardPractice for
Longevity Assessment of Firestop Materials Using
Differential Scanning Calorimetry
This standard is issued under the fixed designation E2923; 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 bility of regulatory limitations prior to use. Some specific
hazards are given in Section 8 on Hazards.
1.1 This practice covers a standardized procedure for quan-
titatively assessing the longevity of materials used in firestop
2. Referenced Documents
systems, by the use of data obtained from differential scanning
2.1 ASTM Standards:
calorimetry.
E814Test Method for Fire Tests of Penetration Firestop
1.2 This practice is intended to differentiate firestop mate-
Systems
rials that are expected to maintain performance characteristics
E2041Test Method for Estimating Kinetic Parameters by
over time from those that are expected to degrade in perfor-
Differential Scanning Calorimeter Using the Borchardt
mance characteristics over time. DSC experimental curve
and Daniels Method
evaluation can also deliver indifferent results, where an inter-
pretation of sample properties is not possible without addi-
3. Terminology
tionaltestingusingconventionaldurabilitytesting.Itevaluates
3.1 Definitions:
the extent of chemical reactions that will occur within the
3.1.1 firestop material, n—the part of a firestop system that
firestop material under specified conditions of temperature and
providesthenecessarysealtopreventthepassageofflameand
humidity. This practice does not measure longevity under
hot gases when tested in accordance with Test Method E814.
specific severe environmental conditions or building operation
This includes any material that serves the purpose of closing
that might be experienced by an individual firestop system.
and sealing the gap(s) created in a fire-resistance rated wall or
1.3 This practice is intended to be used to test the materials
floor to accommodate a through-penetration.
used within a firestopping system.The practice is not intended
3.1.2 longevity, n—ameasureofthelengthoftimeaproduct
to be used to test the properties of assembled firestopping
meets specified performance requirements.
systems.
3.1.2.1 Discussion—Longevity is not intended to be a mea-
1.4 This practice is intended to evaluate the following types
sure of how long a product retains the precise properties that it
of materials used in through-penetration fire stops:
had at the time of manufacture. Most materials will change
1.4.1 Endothermic,
over time to some extent, so a measurement of time before
1.4.2 Intumescent,
discernible change occurs would not generally be realistic or
1.4.3 Insulation,
useful. Rather, longevity is intended to be a measure of how
1.4.4 Ablatives, and
long a product retains its properties to a sufficient degree to be
1.4.5 Subliming.
deemed as meeting the purpose(s) for which it was manufac-
tured.
1.5 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
4. Summary of Practice
standard.
4.1 A small sample of the firestop material is tested by
1.6 This standard does not purport to address all of the
differential scanning calorimetry in accordance with Test
safety concerns, if any, associated with its use. It is the
Method E2041 to determine the following information:
responsibility of the user of this standard to establish appro-
4.1.1 Calculation of total released energy.
priate safety and health practices and determine the applica-
4.1.2 Determination of reaction order.
This practice is under the jurisdiction of ASTM Committee E06 on Perfor-
mance of Buildings and is the direct responsibility of Subcommittee E06.21 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Serviceability. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved April 1, 2013. Published April 2013. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
E2923–13 the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2923 − 13
4.1.3 Determination of activation energy and Arrhenius temperatures, or for suitability in installations which are
frequency factor. intended to have an unusually long design life, or both.
4.1.4 Calculation of the conversion rate for 270 days at
5.4 Measurement of conversion rate allows longevity of
70°C.
firestop materials to be compared to the longevity of the
4.1.5 Calculationoftheconversionratefor30years(10950
classified wall or floor assemblies in which the firestop system
days) at 50°C.
is installed, by measuring the conversion rate for each. This
4.2 Using the kinetic data, the chemical conversion rate for
comparison can ensure that the firestop system does not
the material can be calculated for any time duration and
degrade significantly faster, thus possibly deeming it to be
temperaturecombination.Theconversionrateforthattimeand
unacceptable.The comparison can also ensure that the firestop
temperatureisthencomparedtothepredeterminedthresholdof system is not unjustifiably held to a higher standard of
acceptability. That threshold shall be expressed as the largest
longevity than the floor or wall itself.
fraction of the original material that shall be permitted to
5.5 The fundamental assumption inherent in making use of
undergochangethroughchemicalreaction(s)whilestillallow-
DSC conversion rate data for assessing longevity of firestop
ing the material to adequately perform its design function.
materials is that if the material has a chemical stability that
keeps it from changing much over time in a certain
5. Significance and Use
environment, then it is reasonable to expect it to adequately
5.1 Firestop systems are exposed to fire tests and classified
perform its design function if subjected to an actual fire many
using materials that have been, in all likelihood, quite recently
years after installation.
manufactured. The testing provides a fire resistance rating for
the firestop system that is measured in hours. The goal of
6. Interferences
firestop system testing is to identify and list firestop systems
6.1 Because of its simplicity and ease of use, the Borchardt
thatwillhaveafireresistanceratingthatisnolessthanthefire
and Daniels method is often the method of choice for charac-
resistance rating of the classified wall or floor assembly in
terization of the kinetic parameters of a reaction system. The
which it is installed.Abuilding fire that could put the firestop
Borchardt and Daniels method, like all tools used to evaluate
system to the test can occur at any time during the life of the
kinetic parameters, is not applicable to all cases. The user of
building. By that time, the firestop system is composed of
this method is expressly advised to use this method and its
materialsthathaveaged.Someassuranceisdesiredtoestablish
results with caution.
quantitatively that the firestop system will continue to have a
fireresistanceratingthatisnolessthanthatofthewallorfloor
6.2 Tabulated below are some guidelines for the use of the
assembly.
Borchardt and Daniels method.
5.2 This practice provides one method for examining 6.2.1 The approach is applicable only to exothermic reac-
whetheranychangesaretobeexpectedinthecharacteristicsof tions.
a firestop material during its design life, as gauged by any
NOTE 1—Endothermic reactions are controlled by the kinetics of the
chemical reactions that occur within the material to change it.
heat transfer of the apparatus and not by the kinetics of the reaction.
The measurement of conversion rate provides a standard
6.2.2 The reaction under investigation must have a constant
measure of how much a material will change over its design
mechanism throughout the whole reaction process. In practice,
life. This provides an objective indication of whether the bulk
this means that the reaction exotherm upon heating must be
of the material is likely to exhibit the desirable properties for
smooth, well shaped with no shoulders, multiple peaks or
which it was chosen in the firestop system.
discontinuous steps.
5.3 Measurementofconversionrateallowsdifferentfirestop
6.2.3 Thereactionmustbe nthorder.Confirmationofan nth
materials used for similar purposes to be compared with
order reaction shall be made by an isothermal experiment such
respecttotheirabilitytoremainunchangedduringtheirdesign
as that described in Appendix X1 in Test Method E2041.
life.
6.2.4 Typicalreactionswhicharenot nthorderandtowhich
5.3.1 This allows materials with an unusually high conver-
Borchardt and Daniels kinetic shall not be applied for predic-
sionratetobequestionedandpossiblyrejectedearlyonduring
tive purposes include many thermoset curing reactions and
the research and development process.
crystallization transformations.
5.3.2 This allows materials to be screened by testing and
6.2.5 The nth order kinetic reactions anticipate that the
listing agencies to ensure that they do not provide a listing for
value of n will be small, non-zero integers, such as 1 or 2.
products that are not likely to have adequate performance for
Values of n >2 or which are not simple fractions, such as ½ =
the full length of the intended design life.
0.5, are highly unlikely and shall be viewed with caution.
5.3.3 Thisallowsformulationchangesthathavenoapparent
impact on the results of the fire testing to be evaluated for any
6.2.6 The Borchardt and Daniels method assumes tempera-
possible long-term consequences on performance. ture equilibrium throughout the whole test specimen. This
5.3.4 Re-calculation of the conversion rate (other than for means that low heating rates, (that is, <10 K/min), small
the standard time and temperature specified in Section 11) specimensizes(<5mg)andhighlyconductivesealedspecimen
allows materials to be evaluated for suitability in applications containers, for example, aluminum, gold, platinum, etc., shall
where they may be regularly exposed to unusually high be used.
E2923 − 13
6.3 Since milligram quantities of specimen are used, it is sprayed or otherwise applied as they normally would to create
essentialthatthespecimenbehomogeneousandrepresentative a sample of thickness which is considered by the test sponsor
of the test sample from which they are taken. and laboratory to represent a typical field installation. The
sampleshallbeallowedtocureordrybeforetesting.Curingor
7. Apparatus drying time shall be in accordance with manufacturer’s pub-
lished instructions for the product.
7.1 Differential Scanning Calorimeter (DSC), the instru-
mentation required to provide the minimum differential scan- 9.3 Inhomogeneous materials.
ning calorimetric capability for this practice includes the 9.3.1 Due to the possibility that a milligram-sized sample
following: might not include one or more constituents of an inhomoge-
7.1.1 DSC Test Chamber, composed of the following: neousmaterial,multiplesamplesshallbetakenandtestedsoas
7.1.1.1 Furnace(s),toprovideuniformcontrolledheatingof to ensure that the kinetic data (Arrhennius coefficients) of all
a specimen and reference to a constant temperature at a constituents of the material have been measured.
constant rate within the applicable temperature range of this
NOTE 3—It is not intended that samples should be prepared and tested
practice.
that would test each individual component as a pure material. The intent
7.1.1.2 Temperature Sensor, to provide an indication of the
is that sufficient samples should be tested that each component has
appeared in at least one test.
specimen/furnace temperature to 60.01 K.
7.1.1.3 Differential Sensor, to detect heat flow difference
9.4 ThesamplestobeusedforDSCtestingshallbeexcised
between the specimen and reference equivalent to 1 µW.
from the material prepared as specified in 9.2.
7.1.1.4 A means of sustaining a test chamber environment
10. Procedure
of purge gas at a rate of 10 to 50 6 mL/min.
10.1 DSC testing shall be conducted on three samples
NOTE 2—Typically, 99.9+ % pure nitrogen, helium, or argon is
prepared as specified in Section 9. The two tests and subse-
employed. Use of dry purge gas is recommended and is essential for
operation at subambient temperatures.
quentdataanalysisshallbeasdescribedinTestMethodE2041,
with exceptions as described in 10.1.1 and 10.1.2.
7.1.2 Temperature Controller, capable of executing a spe-
10.1.1 In one test, the sample shall be in an open container
cific temperature program by operating the furnace(s) between
that is exposed to a pure dry air atmosphere.
selected temperature limits, that is, 170 to 870 K, at a rate of
10.1.2 In one test, the sample shall be in an open container
temperaturechangeofupto10K/minconstantto 60.1K/min.
that is exposed to an airflow that is saturated with water.
7.1.3 Recording Device, capable of recording and display-
inganyfractionoftheheatflowsignal(DSCcurve),including
NOTE 4—Test Method E2041 specifies that a sample to be tested by
the signal noise, on the Y-axis versus temperature on the
DSC is to be contained within a hermetically sealed container. The two
independent tests specified here place the sample in an open container,
X-axis.
each of which is exposed to a different atmospheric condition. These two
7.2 Containers (pans, crucibles, vials, etc.), that are inert to
conditions represent extremes of environmental conditions that a firestop
thespecimenandreferencematerials,andwhichareofsuitable product might be exposed to during its design life: very dry air, and very
humid air.
structural shape and integrity to contain the specimen and
reference in accordance with the specific requirements of this
11. Calculation or Interpretation of Results
practice.
11.1 For each DSC test conducted, the conversion rate of
7.3 Whilenotrequired,theuserwillfindusefulcalculatoror
the material shall be calculated for the following two time and
computer and data analysis software to perform the necessary
temperature combinations:
least squares best fit or multiple linear regression data treat-
11.1.1 Two hundred and seventy (270) days at 70°C.
ments required by this practice.
11.1.2 Thirty (30) years (10 950 days) at 50°C.
7.4 Balance, to weigh specimens, or containers, or both, to
11.2 The calculation of the conversion rate shall be as
610 µg with a capacity of at least 100 mg.
detailed below:
11.2.1 Calculate the rate of reaction using the calculations
8. Hazards
presented in the Calculation Section of Test Method E2041.
8.1 This practice
...
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