ASTM C1564-04(2009)

Standard Guide for Use of Silicone Sealants for Protective Glazing Systems

SIGNIFICANCE AND USE
Guidelines are provided for the use of silicone sealants in protective glazing. Protective glazing incorporates various forms of glazing that are not covered in Guides C 1401 and C 1193. The requirements for a sealant in protective glazing are similar to the requirements for structural sealant glazing but for certain applications such as missile impact and bomb blast glazing, sealant requirements may be greater. Modes of failure for bomb blast glazing can be different than the modes of failure for missile impact glazing.
Many types of protective glazing systems are relatively new and the test methods and standards for protective glazing are continually evolving. Because the demands on a sealant in protective glazing systems are changing, guidelines are necessarily general in many instances.
As a component of a glazing system, the sealant can be a factor in whether a glazing system meets the requirements of a specific test method but other factors such as the frame and glass type may be of greater influence.
The designer of a protective glazing system should consult with the various manufacturers of the component materials. The experience and judgment of the glazing system designer working with the sealant manufacturer and other component manufacturers can ultimately determine whether a specific glazing system will successfully meet a specific test requirement.
SCOPE
1.1 This guide covers the use of silicone sealants in protective glazing systems for building construction. Protective glazing includes systems designed for use in applications subject to natural disasters such as hurricanes, earthquakes, windstorms and forms of forced entry such as blasts, burglary, and ballistic attack.
1.2 While other glazing accessories and components are used in protective glazing, this document specifically describes the use of silicone sealants for protective glazing systems.
1.3 This guide provides information useful to design professionals, architects, manufacturers, installers, and others for the design and installation of silicone sealants for protective glazing systems.
1.4 A silicone sealant is only one component of a glazing system. A glazing system that meets the testing and code requirement for impact glazing must successfully integrate the frame and its anchorage, glass, or other glazing materials, protective film or interlayer and silicone sealant into a high performance system. Compliance with code or other requirements can be determined through physical testing of the glazing system or through computer simulation.
1.5 Glazing systems using silicone sealants that have successfully met the test requirements for missile impact and bomb blast test requirements incorporate the use of silicone sealants specifically formulated, tested, and marketed for this application. Sealants that are commonly used today comply with Specifications C 920 and C 1184.
1.6 This guide does not discuss sealants intended to protect against radioactivity or provide biological containment.
1.7 The committee with jurisdiction over this standard is not aware of any comparable standards published by other organizations.
1.8 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 requirements prior to use.

General Information

• Status: Historical
• Publication Date: 31-May-2009
• ICS: 71.100.55 - Silicones
• Technical Committee: C24 - Building Seals and Sealants
• Drafting Committee: C24.10 - Specifications, Guides and Practices

Relations

• Replaces: ASTM C1564-04 - Standard Guide for Use of Silicone Sealants for Protective Glazing Systems
• Effective Date: 01-Jun-2009
• Replaced By: ASTM C1564-15 - Standard Guide for Use of Silicone Sealants for Protective Glazing Systems
• Effective Date: 01-Dec-2015
• Referred By: ASTM F2248-19 - Standard Practice for Specifying an Equivalent 3-Second Duration Design Loading for Blast Resistant Glazing Fabricated with Laminated Glass
• Effective Date: 01-Jun-2009
• Referred By: ASTM C1472-16(2022) - Standard Guide for Calculating Movement and Other Effects When Establishing Sealant Joint Width
• Effective Date: 01-Jun-2009
• Referred By: ASTM C1401-23 - Standard Guide for Structural Sealant Glazing
• Effective Date: 01-Jun-2009

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: C1564 − 04(Reapproved 2009)
Standard Guide for
Use of Silicone Sealants for Protective Glazing Systems
This standard is issued under the fixed designation C1564; 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 responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This guide covers the use of silicone sealants in protec-
bility of regulatory requirements prior to use.
tive glazing systems for building construction. Protective
glazing includes systems designed for use in applications
2. Referenced Documents
subject to natural disasters such as hurricanes, earthquakes,
2.1 ASTM Standards:
windstorms and forms of forced entry such as blasts, burglary,
C717 Terminology of Building Seals and Sealants
and ballistic attack.
C719 Test Method for Adhesion and Cohesion of Elasto-
1.2 While other glazing accessories and components are
meric Joint Sealants Under Cyclic Movement (Hockman
used in protective glazing, this document specifically describes
Cycle)
the use of silicone sealants for protective glazing systems.
C794 Test Method forAdhesion-in-Peel of Elastomeric Joint
1.3 This guide provides information useful to design Sealants
professionals, architects, manufacturers, installers, and others C920 Specification for Elastomeric Joint Sealants
forthedesignandinstallationofsiliconesealantsforprotective C1087 Test Method for Determining Compatibility of
glazing systems. Liquid-Applied Sealants with Accessories Used in Struc-
tural Glazing Systems
1.4 A silicone sealant is only one component of a glazing
C1135 Test Method for Determining TensileAdhesion Prop-
system. A glazing system that meets the testing and code
erties of Structural Sealants
requirement for impact glazing must successfully integrate the
C1184 Specification for Structural Silicone Sealants
frame and its anchorage, glass, or other glazing materials,
C1193 Guide for Use of Joint Sealants
protective film or interlayer and silicone sealant into a high
C1394 Guide for In-Situ Structural Silicone Glazing Evalu-
performance system. Compliance with code or other require-
ation
ments can be determined through physical testing of the
C1401 Guide for Structural Sealant Glazing
glazing system or through computer simulation.
C1472 Guide for Calculating Movement and Other Effects
1.5 Glazing systems using silicone sealants that have suc-
When Establishing Sealant Joint Width
cessfully met the test requirements for missile impact and
D624 Test Method for Tear Strength of Conventional Vul-
bomb blast test requirements incorporate the use of silicone
canized Rubber and Thermoplastic Elastomers
sealants specifically formulated, tested, and marketed for this
E631 Terminology of Building Constructions
application. Sealants that are commonly used today comply
E1886 Test Method for Performance of Exterior Windows,
with Specifications C920 and C1184.
Curtain Walls, Doors, and Impact Protective Systems
1.6 This guide does not discuss sealants intended to protect Impacted by Missile(s) and Exposed to Cyclic Pressure
Differentials
against radioactivity or provide biological containment.
F1642 Test Method for Glazing and Glazing Systems Sub-
1.7 Thecommitteewithjurisdictionoverthisstandardisnot
ject to Airblast Loadings
aware of any comparable standards published by other orga-
2.2 GSA Standard:
nizations.
US General Services Administration (GSA) Standard Test
1.8 This standard does not purport to address all of the
Method for Glazing and Window Systems Subject to
safety concerns, if any, associated with its use. It is the 3
Dynamic Overpressure Loading
1 2
ThisguideisunderthejurisdictionofASTMCommitteeC24onBuildingSeals For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Sealants and is the direct responsibility of Subcommittee C24.10 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Specifications, Guides and Practices. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2009. Published June 2009. Originally the ASTM website.
approved in 2003. Last previous edition approved in 2004 as C1564 – 04. DOI: U.S. General Services Administration (GSA), 1800 F Street, NW Washington,
10.1520/C1564-04R09. DC 20405
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1564 − 04 (2009)
3. Terminology must meet demanding test requirements and that considered
separately may or may not have a significant impact on system
3.1 Definitions—Refer to Terminologies C717 and E631 for
performance.
definitions of terms used in this guide.
6. Sealant Considerations
4. Significance and Use
6.1 Depending on the specific requirement of the protective
4.1 Guidelines are provided for the use of silicone sealants
glazing system, the properties of the sealant can perform a
in protective glazing. Protective glazing incorporates various
significant role in the overall performance of the system.
forms of glazing that are not covered in Guides C1401 and
Important properties to consider when selecting a sealant for
C1193.The requirements for a sealant in protective glazing are
any glazing system include the following:
similar to the requirements for structural sealant glazing but for
6.1.1 Adhesion—Sealant adhesion should be confirmed as
certain applications such as missile impact and bomb blast
glazing, sealant requirements may be greater. Modes of failure acceptable to the components of the glazing system including
for bomb blast glazing can be different than the modes of
glass, glass coatings, metal, wood, plastic, film laminate, or
failure for missile impact glazing. other material to which adhesion is required. Adhesion can be
determined using Test Methods C794 or C1135. The adhesion
4.2 Many types of protective glazing systems are relatively
requirements specified in Specification C1184 should be con-
new and the test methods and standards for protective glazing
sidered as the minimum requirement for most missile impact
are continually evolving. Because the demands on a sealant in
and bomb blast glazing systems. Guide C1193 includes a
protective glazing systems are changing, guidelines are neces-
discussion on adhesion and testing that may be helpful.
sarily general in many instances.
6.1.2 Compatibility—Sealant compatibility with each of the
4.3 As a component of a glazing system, the sealant can be
glazing components should be verified. Components include
a factor in whether a glazing system meets the requirements of
PVB, polycarbonate or a similar interlayer of laminated glass,
a specific test method but other factors such as the frame and
insulating glass unit edge sealants, glazing and other gasket
glass type may be of greater influence.
and spacer materials, and metal framing materials and factory
4.4 The designer of a protective glazing system should
applied coatings. Compatibility with gasket or other accessory
consult with the various manufacturers of the component
materials is determined using Test Method C1087. Guide
materials. The experience and judgment of the glazing system
C1193 includes a discussion on compatibility and testing that
designer working with the sealant manufacturer and other
may be helpful.
component manufacturers can ultimately determine whether a
6.1.3 Strength and Modulus—Sealant strength and modulus
specific glazing system will successfully meet a specific test
are very important factors in determining whether a glazing
requirement.
system will pass a specific protective glazing requirement. A
sealant with an ultimate tensile strength that is too low may not
5. Introduction
be able to support the glazing through a specific missile impact
or bomb blast test requirement. As a guide, the strength and
5.1 Protective glazing systems are designed for the protec-
modulus requirements identified in Specification C1184 should
tion of the building occupants and general public from various
be followed. For some applications, such as encountered in
natural and man-made occurrences that could cause injury or
certain bomb blast test requirements, these strength and modu-
damage. Natural disasters include hurricanes, earthquakes, and
lus requirements may not be high enough and a higher strength
windstorms, which with their high winds and wind-driven rain
structural silicone will be required. Since certain high modulus
can cause failure to joint sealants. Additionally, flying debris
resulting from high winds can cause damage to the glazing sealants have lower movement capability, considerations
system. Test methods such as Test Method E1886 simulate the should be made to ensure that annual movement on the sealant
effect of flying debris during a windstorm. Man-made occur- joint does not exceed the movement capability of the sealant.
rences include bomb blast, ballistic attack, burglary, and
6.1.4 Tear Characteristics and Fatigue—Along with
vandalism. Test methods such as Test Method E1886 and GSA
strength and modulus, the ability of a sealant to withstand the
Standard Test Method for Glazing and Window Systems
cyclic loading of certain protective glazing test methods is
Subject to Dynamic Overpressure Loading provide procedures
important. Tear strength as determined by Test Method D624
for the testing of glazing systems subject to bomb blast.
can be useful in determining whether a sealant can withstand
Computer software programs such asWINGARD orWINLAC
theimpulseloadofablasttestorthecyclicloadingofamissile
maybeusedtoevaluatetheeffectsofabombblastonaglazing
impact test. The ability of a sealant to withstand the fatigue
system.
associated with cyclic loading is an important consideration
that may deem a sealant appropriate for missile impact
5.2 Asealant can play a crucial role in retaining the glazing
applications.
material in the opening and thus preserving the integrity of the
buildingenvelope.Ifthebuildingenvelopeislostduetofailure 6.1.5 Durability—Sealant durability is important in protec-
of the glazing system, the building can become pressurized tive glazing. A sealant used in protective glazing is subject to
resulting in significant damage to the structure, its contents and a broad range of environmental factors including: Temperature
its occupants. The type of framing system, glazing material(s), cycling, solar radiation exposure, moisture from the environ-
and sealant are major components of a glazing system that ment or condensation, ozone, and airborne pollutants. These
C1564 − 04 (2009)
factors can cause premature failure of certain sealant types. manner similar to a structural sealant and the properties of the
Guide C1193 includes a discussion on sealant durability and sealant and design of the sealant joint are important. Bite and
testing. thickness are two terms used to describe the dimensions of a
6.1.6 Movement Capability—The movement capability of a structural joint (see Guide C1401). These terms also apply
sealant is important if the sealant also serves as a weatherseal
when describing a non-structural glazing system. The joint
in a protective glazing system. Consideration of a sealant’s design must be sufficient to allow the joint surfaces to be
movement capability is important for a glazing system to
properly cleaned and allow adequate sealant application into
remain watertight and function as intended. Environmental the joint opening. See 8.3 for a discussion of sealant curing
thermal cycling and other framing system movements may
considerations.
impact the ability of a sealant to perform as a weatherseal.
7.3.1 Structural Sealant Glazed Joint—A silicone sealant
Sealant joint design is important in determining if a sealant can
may be used in a structural sealant glazed system that is also
performasforaweatherseal.TestMethodC719shouldbeused
expected to meet certain protective glazing requirements. At
to determine movement capability of a sealant. Guides C1193
least the bite and thickness minimum guidelines stated in
and C1472 should be used to determine proper sealant joint
Specification C1184 and Guide C1401 must be met. Glazing
design.
systems which have passed either small or large missile impact
tests have bite dimensions of at least 12 mm ( ⁄2 in.) and in
7. Design Considerations
some cases bite dimensions of 19 mm ( ⁄4 in.) to 25 mm (1 in.)
7.1 Currently there are no industry-accepted standards for
have been required. Other key factors affecting glazing system
the design of sealant joints in protective glazing systems. The
performance include glass selection, bite configuration, frame
considerations discussed below are based on findings from
strength, and other factors. Currently, actual full-scale perfor-
actual tests of protective glazing systems according to Test
mance is used to establish appropriate bite or thickness
Methods E1886, F1642, and GSA Standard Test Method for
dimension necessary to successfully pass a missile impact test.
Glazing and Glazing Systems Subject to Airblast Loadings.
Typical structurally glazed systems designed to pass missile
Unlike structural glazing where joint dimensions can be
impact test requirements are shown in Figs. 1-3. Fig. 1
calculated and precisely determined, this capability does not
illustrates a typical system with monolithic glass lite with a
exist for the design of joints in protective glazing systems.
laminate and polycarbonate coating on the interior facing
Variables such as glass type and dimension, laminate type,
surface of the glazing. Fig. 2 illustrates a conventional lami-
framing system, anchoring, applied loads, and other factors
nated glass. Fig. 3 illustrates a laminated insulating glass unit.
will all have an impact on the performance of the sealant joint
7.3.2 Non-Structural Sealant Glazed Joint—A sealant may
in a protective glazing system.
also be used in a glazing system where it is not intended to
7.2 Applied Loads—Protective glazing that is designed to
support the glass structurally under windload. In protective
resist bomb blast criteria must also be designed to resist other
glazing, the sealant serves the dual purpose as a weatherseal in
lateral loads such as those required by the local building code,
the glazing system and as an anchor for the glazing in missile
which usually include lateral wind loads and seismic events.
impact or blast testing. The sealant performs non-structurally
For example, sometimes the design requiremen
...

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:C1564–03 Designation: C 1564 – 04 (Reapproved 2009)
Standard Guide for
Use of Silicone Sealants for Protective Glazing Systems
This standard is issued under the fixed designation C 1564; 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 guide is for covers the use of silicone sealants in protective glazing systems for building construction. Protective
glazing includes systems designed for use in applications subject to natural disasters such as hurricanes, earthquakes, windstorms
and forms of forced entry such as blasts, burglary, and ballistic attack.
1.2 While other glazing accessories and components are used in protective glazing, this document specifically describes the use
of silicone sealants for protective glazing systems.
1.3 This guide provides information useful to design professionals, architects, manufacturers, installers, and others for the
design and installation of silicone sealants for protective glazing systems.
1.4 Asilicone sealant is only one component of a glazing system.Aglazing system that meets the testing and code requirement
for impact glazing must successfully integrate the frame and its anchorage, glass, or other glazing materials, protective film or
interlayer and silicone sealant into a high performance system. Compliance with code or other requirements can be determined
through physical testing of the glazing system or through computer simulation.
1.5 Glazing systems using silicone sealants that have successfully met the test requirements for missile impact and bomb blast
test requirements incorporate the use of silicone sealants specifically formulated, tested, and marketed for this application. Sealants
that are commonly used today comply with Specifications C 920 and C 1184.
1.6 This guide does not discuss sealants intended to protect against radioactivity or provide biological containment.
1.7 The committee with jurisdiction over this standard is not aware of any comparable standards published by other
organizations.
1.8 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
requirements prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 717 Terminology of Building Seals and Sealants
C 719 Test Method forAdhesion and Cohesion of Elastomeric Joint Sealants underUnder Cyclic Movement (Hockman Cycle)
C 794 Test Method for Adhesion-in-Peel of Elastomeric Joint Sealants
C 920 Specification for Elastomeric Joint Sealants
C 1087 Test Method for Determining Compatibility of Liquid-Applied Sealants with Accessories Used in Structural Glazing
Systems
C 1135 Test Method for Determining Tensile Adhesion Properties of Structural Sealants
C 1184 Specification for Structural Silicone Sealants
C 1193 Guide for Use of Joint Sealants
C 1394 Guide for In-Situ Structural Silicone Glazing Evaluation
C 1401 Guide for Structural Sealant Glazing
C 1472 Guide for Calculating Movement and Other Effects When Establishing Sealant Joint Width
D 624 Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplastic Elastomers
E 631 Terminology of Building Constructions
E 1886 Test Method for Performance of ExteriorWindows, Glazed CurtainWalls, Doors, and Storm Shutters Impact Protective
Systems Impacted by Missile(s) and Exposed to Cyclic Pressure Differentials
This guide is under the jurisdiction ofASTM Committee C24 on Building Seals and Sealants and is the direct responsibility of Subcommittee C24.10 on Specifications,
Guides, and Practices.
Current edition approved July 10, 2003. Published August 2003.on Specifications, Guides and Practices.
Current edition approved June 1, 2009. Published June 2009. Originally approved in 2003. Last previous edition approved in 2004 as C 1564 – 04.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
, Vol 04.07.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 1564 – 04 (2009)
F 1642 Test Method for Glazing and Glazing Systems Subject to Airblast Loadings
2.2 GSA Standard:
US General Services Administration (GSA) Standard Test Method for Glazing and Window Systems Subject to Dynamic
Overpressure Loading
3. Terminology
3.1 Definitions—Refer to Terminologies C 717 and E 631 for definitions of terms used in this guide.
4. Significance and Use
4.1 Guidelines are provided for the use of silicone sealants in protective glazing. Protective glazing incorporates various forms
of glazing that are not covered in Guides C 1401 and C 1193. The requirements for a sealant in protective glazing are similar to
the requirements for structural sealant glazing but for certain applications such as missile impact and bomb blast glazing, sealant
requirements may be greater. Modes of failure for bomb blast glazing can be different than the modes of failure for missile impact
glazing.
4.2 Many types of protective glazing systems are relatively new and the test methods and standards for protective glazing are
continually evolving. Because the demands on a sealant in protective glazing systems are changing, guidelines are necessarily
general in many instances.
4.3 As a component of a glazing system, the sealant can be a factor in whether a glazing system meets the requirements of a
specific test method but other factors such as the frame and glass type may be of greater influence.
4.4 The designer of a protective glazing system should consult with the various manufacturers of the component materials. The
experience and judgment of the glazing system designer working with the sealant manufacturer and other component
manufacturers can ultimately determine whether a specific glazing system will successfully meet a specific test requirement.
5. Introduction
5.1 Protective glazing systems are designed for the protection of the building occupants and general public from various natural
and man-made occurrences that could cause injury or damage. Natural disasters include hurricanes, earthquakes, and windstorms,
which with their high winds and wind-driven rain can cause failure to joint sealants.Additionally, flying debris resulting from high
windscancausedamagetotheglazingsystem.TestmethodssuchasTestMethodE 1886simulatetheeffectofflyingdebrisduring
a windstorm. Man-made occurrences include bomb blast, ballistic attack, burglary, and vandalism. Test methods such as Test
Method E 1886 and GSA Standard Test Method for Glazing and Window Systems Subject to Dynamic Overpressure Loading
provide procedures for the testing of glazing systems subject to bomb blast. Computer software programs such as WINGARD or
WINLAC may be used to evaluate the effects of a bomb blast on a glazing system.
5.2 A sealant can play a crucial role in retaining the glazing material in the opening and thus preserving the integrity of the
building envelope. If the building envelope is lost due to failure of the glazing system, the building can become pressurized
resulting in significant damage to the structure, its contents and its occupants.The type of framing system, glazing material(s), and
sealant are major components of a glazing system that must meet demanding test requirements and that considered separately may
or may not have a significant impact on system performance.
6. Sealant Considerations
6.1 Depending on the specific requirement of the protective glazing system, the properties of the sealant can perform a
significant role in the overall performance of the system. Important properties to consider when selecting a sealant for any glazing
system include the following:
6.1.1 Adhesion—Sealant adhesion should be confirmed as acceptable to the components of the glazing system including glass,
glass coatings, metal, wood, plastic, film laminate, or other material to which adhesion is required. Adhesion can be determined
using Test Methods C 794 or C 1135. The adhesion requirements specified in Specification C 1184 should be considered as the
minimum requirement for most missile impact and bomb blast glazing systems. Guide C 1193 includes a discussion on adhesion
and testing that may be helpful.
6.1.2 Compatibility—Sealant compatibility with each of the glazing components should be verified. Components include PVB,
polycarbonate or a similar interlayer of laminated glass, insulating glass unit edge sealants, glazing and other gasket and spacer
materials, and metal framing materials and factory applied coatings. Compatibility with gasket or other accessory materials is
determined using Test Method C 1087. Guide C 1193 includes a discussion on compatibility and testing that may be helpful.
6.1.3 Strength and Modulus—Sealant strength and modulus are very important factors in determining whether a glazing system
will pass a specific protective glazing requirement. A sealant with an ultimate tensile strength that is too low may not be able to
support the glazing through a specific missile impact or bomb blast test requirement. As a guide, the strength and modulus
requirements identified in Specification C 1184 should be followed. For some applications, such as encountered in certain bomb
Annual Book of ASTM Standards, Vol 09.01.
U.S. General Services Administration (GSA), 1800 F Street, NW Washington, DC 20405
C 1564 – 04 (2009)
blast test requirements, these strength and modulus requirements may not be high enough and a higher strength structural silicone
will be required. Since certain high modulus sealants have lower movement capability, considerations should be made to ensure
that annual movement on the sealant joint does not exceed the movement capability of the sealant.
6.1.4 Tear Characteristics and Fatigue— Along with strength and modulus, the ability of a sealant to withstand the cyclic
loading of certain protective glazing test methods is important. Tear strength as determined by Test Method D 624 can be useful
in determining whether a sealant can withstand the impulse load of a blast test or the cyclic loading of a missile impact test. The
ability of a sealant to withstand the fatigue associated with cyclic loading is an important consideration that may deem a sealant
appropriate for missile impact applications.
6.1.5 Durability—Sealant durability is important in protective glazing.Asealant used in protective glazing is subject to a broad
range of environmental factors including: Temperature cycling, solar radiation exposure, moisture from the environment or
condensation, ozone, and air-borneairborne pollutants. These factors can cause premature failure of certain sealant types. Guide
C 1193 includes a discussion on sealant durability and testing.
6.1.6 Movement Capability—The movement capability of a sealant is important if the sealant also serves as a weatherseal in
a protective glazing system. Consideration of a sealant’s movement capability is important for a glazing system to remain
watertight and function as intended. Environmental thermal cycling and other framing system movements may impact the ability
of a sealant to perform as a weatherseal. Sealant joint design is important in determining if a sealant can perform as for a
weatherseal. Test Method C 719 should be used to determine movement capability of a sealant. Guides C 1193 and C 1472 should
be used to determine proper sealant joint design.
7. Design Considerations
7.1 Currently there are no industry-accepted standards for the design of sealant joints in protective glazing systems. The
considerations discussed below are based on findings from actual tests of protective glazing systems according to Test Methods
E 1886, F 1642, and GSAStandard Test Method for Glazing and Glazing Systems Subject toAirblast Loadings. Unlike structural
glazing where joint dimensions can be calculated and precisely determined, this capability does not exist for the design of joints
inprotectiveglazingsystems.Variablessuchasglasstypeanddimension,laminatetype,framingsystem,anchoring,appliedloads,
and other factors will all have an impact on the performance of the sealant joint in a protective glazing system.
7.2 Applied Loads—Protective glazing that is designed to resist bomb blast criteria must also be designed to resist other lateral
loads such as those required by the local building code, which usually include lateral wind loads and seismic events. For example,
sometimes the design requirements for protective glazing to resist a bomb blast can differ from those for an applied lateral load
from the local wind environment. Glass or a glass composite product with the necessary strength and deflection characteristics for
a protective glazing system, when designed for bomb blast resistance, may not have the necessary strength and deflection
characteristics to resist a building code or laboratory test determined wind load. The designer of a protective glazing system may
havetoconsiderbothbombblastandwindloadrequirements.Doingsomaychangethedesignrequirementsforatleasttheglazing
product, glazing sealant joint, glazed opening metal framing, and framing anchorage requirements from those solely required for
resisting a bomb blast.
7.3 Joint Sizing and Dimensions—As important as the selection of sealant is the geometry of the sealant joint in the glazing
system. In a protective glazing system, the sealant joint may be either structural or non-structural. For a structural joint, the
applicable requirements of Specification C 1184 and Guide C 1401 should be considered. For a non-structural application, the
sealant does not act to structurally support the glazing under the influence of a wind-load but would be expected to retain the
glazing in the framing system during the testing or during an actual event. In this respect, the sealant does act in a manner similar
to a structural sealant and the properties of the sealant and design of the sealant joint are important. Bite and thickness are two
terms used to describ
...