Thermal Analysis of Fire Resistive Joint Design for
Architectural Expansion Joints
by
Jason A. Shaw
An Abstract of a Thesis Submitted to the Graduate
Faculty of Rensselaer Polytechnic Institute
in Partial Fulfillment of the
Requirements for the degree of
MASTER OF ENGINEERING
Major Subject: Heat Transfer
The original of the complete thesis is on file
In the Rensselaer Polytechnic Institute Library
Approved:
____________________________________________________
Professor Ernesto Gutierrez-Miravete, Thesis Adviser
Rensselaer Polytechnic Institute
Troy, New York
Month, Year
(For Graduation August 2013)
© Copyright 2013
by
Jason A. Shaw
All Rights Reserved
i
CONTENTS
LIST OF TABLES ............................................................................................................ iii
LIST OF FIGURES .......................................................................................................... iv
ACKNOWLEDGMENT ................................................................................................... v
ABSTRACT ...................................................................................................................... 1
INTRODUCTION/BACKGROUND ................................................................................ 2
LITERATURE REVIEW .................................................................................................. 5
THEORY/METHODOLOGY ........................................................................................... 6
ii
LIST OF TABLES
iii
LIST OF FIGURES
Figure 1: Example of an Architectural Expansion Joint .................................................... 2
Figure 2: Illustration of Fire Barrier Design ...................................................................... 4
iv
ACKNOWLEDGMENT
Type the text of your acknowledgment here.
v
ABSTRACT
Type the text of your abstract here.
1
INTRODUCTION/BACKGROUND
Architectural expansion joints are openings or gaps that are designed into the
structure of a building to permit movement between the concrete slabs or other structural
members. Building movement can occur for several reasons, including thermal loading
(i.e., change of weather season), wind loading, or seismic activity. These openings can
vary anywhere between 0.5 inches up to and exceeding 32 inches. Typically, a metal
cover plate is installed over the expansion joint to conceal the joint and to permit
pedestrian traffic across the joint. An example of an architectural expansion joint can be
seen in Figure 1.
Figure 1: Example of an Architectural Expansion Joint
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Building codes often require that these expansion joints include a fire resistive
system, or fire barrier, to prevent the spread of smoke, heat, and flames in the event of a
fire.
American Society for Testing and Materials (ASTM) E1966, "Standard Test
Method for Fire-Resistive Joint Systems", Reference (a), is the standard test method
used to evaluate the performance of a fire barrier system. The acceptance criteria for the
standard is that the transmission of heat through the fire barrier must not raise the
average temperature of the unexposed side more than 250⁰F. The barrier is then rated as
having satisfied the acceptance criteria for a stated period of time (0.5 hours, 1 hour, or 2
hours).
Additionally, since these expansion joints are designed to permit building
movement, the fire barriers themselves must be capable of moving with the joint while
maintaining the fire barriers integrity. ASTM E1399, "Standard Test Method for Cyclic
Movement and Measuring the Minimum and Maximum Joint Widths of Architectural
Joint Systems", Reference (b), is the standard test method used to verify the movement
capability of a fire barrier system.
Underwriters Laboratories (UL) 2079, "Standard for Tests for Resistance of
Building Joint Systems", Reference (c), combines the requirements of both ASTM
E1966 and ASTM E1399, as well as other standards, to test a complete architectural
expansion joint system (cover plate and fire barrier). This is the standard test used in
industry today to qualify cover plate and fire barrier designs.
The fire barrier design of interest is illustrated in Figure 2. The fire barrier consists
of the following basic components (working from the unexposed boundary to the
exposed boundary):

Two galvanized steel "L" brackets - Used to attach the fire barrier the
concrete floor slabs and to provide some axial rigidity.

Ceramic fiber blanket - Used as the main insulation material. Number of
layers and the thickness varies based on fire barrier rating.

Stainless steel foil - Used as an insulation material (radatiave shield), to
prevent the transmission of hot gasses, and to provide some rigidity to the
fire barrier assembly.
3

High temperature cloth - Used to provide structural support for the fire
barrier and as an insulation material.
Figure 2: Illustration of Fire Barrier Design
The goal of this project is to validate the fire barrier design based on the
requirements set forth in UL 2079 for a 2 hour rating. If the proposed configuration does
not satisfy the UL 2079 requirement, recommendations will be made.
4
LITERATURE REVIEW
Several investigators have published documents on thermal analysis of fire barriers
used for architectural expansion joints. Of particular interest is the American Society of
Mechanical Engineers (ASME) paper titled "Transient Heat Transfer for Layered
Ceramic Insulation and Stainless Foil Fire Barriers", Reference (d). This paper develops
a course numerical one dimensional model for a fire barrier in a standard test situation
that is tested to ASTM E119, "Standard Methods of Fire Tests of Building Construction
and Materials".
The Reference (d) paper first conducts a test in accordance with ASTM E119, which
has the same acceptance criteria as ASTM E1399 (unexposed side temperature rise less
than 250⁰F). Reference (d) then develops and applies a numerical model, which is a
course finite difference/finite volume formulation of the standard transient conduction
energy equation with radiative heat flux and the radiative heat transfer equation. While
the numerical model was able to predict the thermal performance of the test system, the
test setup and subsequent analysis is for a geometrically different fire barrier design and
application.
In addition to the Reference (d) paper, the ASME paper titled "Simulations of
Thermal Performance for One- and Two- Dimensional Insulation and Aluminum Foil
Fire Barriers", Reference (e), discusses thermal models of fire barriers. This paper
focuses on the thermal interactions of 2-D architectural expansion joint corners (i.e., a
90⁰ directional change), and if "hot spots" form or any degradation in thermal
performance occurs at these corners. In order to quantify this, a numerical simulation of
the fire barrier is accomplished. The analysis suggested that a fire barrier at a 2-D
architectural expansion joint corner is thermally less robust than a standard 1-D straight
architectural expansion joint.
While the numerical simulation was successful in
matching the thermal performance of previously tested system, the analysis is for a fire
barrier design at a corner is
5
THEORY/METHODOLOGY
6
REFERENCES
(a) Standard Test Method for Fire-Resistive Joint Systems, ASTM E1966
(b) Standard Test Method for Cyclic Movement and Measuring the Minimum and
Maximum Joint Widths of Architectural Joint Systems, ASTM E1399
(c) Standard for Tests for Resistance of Building Joint Systems, UL 2079
(d) Transient Heat Transfer for Layered Ceramic Insulation and Stainless Foil Fire
Barriers, ASME Paper
(e) Simulations of Thermal Performance for One- and Two- Dimensional Insulation
and Aluminum Foil Fire Barriers, ASME Paper
7