The two standards are examined to assess how products evaluated to the
UL2079 (North American) standard would be expected to perform when evaluated
using the AS1530.4 (Australian/NZ) standard.
It was discovered that the AS1530.4 standard does not specifically address
building expansion joints, and has no provisions for incorporating expansion
joint movement into the overall fire rating. As such, the AS1530.4 standard
would not be best suited for the evaluation of building joints such as
structural expansion joint openings that are larger than control joints
where little or no movement is expected.
The AS1530.4 standard has a somewhat more severe oven profile than the
UL2079, but allows for a 2.5% deviation which would theoretically allow the
UL2079 oven profile. An FEA model which closely correlates with actual
UL2079 test data, modified to incorporate the AS1530.4 requirements, proves
the materials tested under the UL standard would pass the slightly higher AS
standard oven profile with a broad safety margin.
Systems passing AS1530.4 have not undergone any cycling component, and as
such, it is unknown how cycling will affect the products FR performance.
Systems passing AS1530.4 are not tested at the maximum joint opening
determined by the manufacturers’ published movement capability.
Systems passing AS 1530.4 were not tested at field-executed splices, and as
such, it is unknown how the tested materials would perform where joined in
Systems passing AS1530.4 in walls have not undergone a hose-stream test
following the fire test to demonstrate the products ability to remain in
place and resist impact from falling debris during a fire.
In most other aspects, it is felt that the two standards would provide a
roughly equivalent predictor of protection.
The Australian standard AS4072.1 “Components for the Protection of Openings
in Fire-Resistant Separating Elements” is intended to be used in conjunction
with AS1530.4 “Methods for Fire Tests on Building Materials, Components and
Structures” which contains the procedures for the doing the evaluations.
UL2079 “Tests for Fire Resistance of Building Joint Systems”, is a North
American standard promoted by Underwriters Laboratories which leverages
previously accepted ASTM (American Society of Testing Materials) standards.
In both tests, the goal is to provide a uniform set of conditions to allow
building designers, and manufacturers to determine the fire resistance of
AS1530.4 is a more general standard than UL2079, including such items as
structural elements (columns and trusses), walls, floors, roofs, door sets,
shutters, glazing, air ducts, dampers, service penetrations and control
AS4072.1 refers to a control joint as “A joint, between or within discrete
elements of construction, that allows for relative movement of the
elements”. This is closely analogous to UL2079 definition of a building
joint system, although UL further stipulates that a control joint should not
exceed 5/8” (16mm) in width. UL does not, however, stipulate that control
joints cannot be qualified under UL2079.
In both tests, the main component is a timed exposure of the building
element in question to heat, under controlled conditions created by a
furnace. The furnace is operated in a fashion to achieve, within reasonable
limits, a prescribed time-temperature curve. The elapsed time at which
failure is seen is recorded.
The fire rating for AS1530.4 is called the Fire Resistance Level (FRL). It
is designated in minutes, and is noted discretely for three performance
criteria: structural adequacy, integrity, and insulation. For example a load
bearing wall might have an FRL of 120/120/120 meaning it satisfies the
standard to a minimum of 2 hours for all three criteria. Where a criterion
is not applicable, the value is indicated with a dash. For example, a
control joint, might have an FRL of --/120/120, since it is a non-load
UL2079 provides a similar fire rating, as time to failure, usually provided
in hours. The UL2079 rating includes a structural component, an integrity
component, and an insulation component although it is not possible, usually,
to separate them. A failure of integrity generally means a failure of
insulation. It is not possible to have a 2 hour integrity rating and only a
1 hour insulation rating. The rating would be given as the lower of the two
values: 1 hour. In this discussion, it is assumed that the joints in
question are non-load bearing, so the structural component of both tests is
Both standards list similar methods for determining integrity failure by
testing any crack, fissure, or opening with a cotton pad. If the cotton pad
ignites then the integrity portion of AS1530.4 is failed. In UL2079, if the
cotton pad ignites, the entire test is failed and the time is noted.
Similarly for the insulation portion in AS1530.4, a failure is noted as an
average unexposed temperature, as measured by thermocouples, of more than
140K above initial. Simultaneously, no single location should be more than
180K above the initial. UL2079 sets these limits at 139K and 181K
respectively. When these values are exceeded in the AS1530.4 test, the
insulation portion of the test is finished although the test can be
continued for the other ratings. In UL2079, the test is finished.
AS1530.4 uses an oven profile described by the equation: T =
345log(8t+1)+20. UL uses the oven profile described in ASTM E-119 “Standard
Test Methods for Fire Tests of Building Construction and Materials”. This
profile produces higher temperatures initially, to approximately 30 minutes,
but slightly lower temperatures from 30 minute onwards. At two hours, the
UL2079 oven temperature is expected to be 1010C, while the AS1530.4
temperature is expected to be 1049C.Both standards make allowances for
variation in temperature by stipulating that the area under the
temperature-time curve be within certain allowances. At greater than 60
minutes, AS1530.4 allows the area under the curve to vary by not more than
2.5%. The area under the AS curve at the two hour mark is 108034
(Kelvin*minutes), while the area under the UL curve at the same time is
105420 K*m. This is a variation of 2.48% which is within the allowable
deviations permitted by the AS1530.4 standard. Nevertheless, the higher
temperatures seen in the AS oven profile necessitated further study, and
this is addressed below in the FEA model.
The movement criteria stipulated in UL2079, create several additional
requirements that have no corresponding requirement within AS1530.4. Since
UL2079 is specifically designed to address the requirements of expansion
joints, and AS1530.4 is not, this is to be expected. However, it is
important to note that the cycling regime in UL2079, especially for cast in
place elastomeric/intumescent mineral wools systems can severely degrade the
integrity of specimen.
In UL2079, a building joint must be cycled between its minimum and maximum
published movements prior to the fire test. The only exception to this
occurs when the manufacturer states that the building joint has no movement
There are three cycling levels that can be tested: thermal (Class I), wind
loading (Class II), and seismic (Class III). UL defines these in terms of
the cycling rate and number of cycles that the joint must endure prior to
the fire test. For thermal cycling, the rate is 1 cycle (defined as nominal
to minimum to maximum and back to nominal) per minute for 500 cycles. Wind
loading is defined as 10 cycles per minute for 500 cycles, and the seismic
rate is defined as 30 cycles per minute for 100 complete cycles. A product
with a published movement must, at minimum, be tested to one of these
levels, and if the seismic rate is desired must additionally be tested at
the wind loading level. UL2079 also requires that the cycled product include
at minimum one factory fabricated splice, and one field splice. UL2079 was
specifically designed to address the movement cycle that building joints are
expected to see in the field while remaining practical. In this respect
UL2079 is a far more stringent test than AS1530.4 and more relevant to the
consideration of the use of materials in high-movement structural expansion
Another key difference in UL2079, again regarding movement, is the
requirement that all joints be fire tested at their maximum published
movement after the cycling regime has been completed. In this respect too,
the UL standard is more stringent than the AS standard as it is understood
that the wider the product being tested, the more heat input goes into the
product and less into the surrounding substrates, making the test more
difficult to pass.
In vertical tests under UL2079, one additional criterion not specified in
AS1530.4, is the Hose Stream Test. After the fire test has been successfully
conducted, the assembly is subjected to a continuous stream of 30psi water
directed from a 1.125” diameter orifice from a distance of 20 feet. The
intent of this test is to assess the structural integrity of the assembly,
not to specifically resist water penetration. If the specimen passes water
through a tear, or crack, the entire assembly has failed the entire standard
irrespective of the fact that the specimen may have passed the fire test.
In this respect as well, the UL standard is more stringent that the AS