ISO 22452:2011
(Main)Timber structures — Structural insulated panel walls — Test methods
Timber structures — Structural insulated panel walls — Test methods
ISO 22452:2011 specifies test methods for determining the structural properties of double-sided, wood-based, load-bearing structural insulated panels (SIPs) for use in walls. It is applicable to SIPs having two face layers, at least one of which is a wood-based structural panel, and a core made of a thermally insulating material with sufficient shear strength to cause the face layers to act together structurally.
Structures en bois — Murs en panneaux isolants structurels — Méthodes d'essai
General Information
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 22452
First edition
2011-06-15
Timber structures — Structural insulated
panel walls — Test methods
Structures en bois — Murs en panneaux isolants structurels —
Méthodes d'essai
Reference number
ISO 22452:2011(E)
©
ISO 2011
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ISO 22452:2011(E)
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ISO 22452:2011(E)
Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 3
5 Product evaluation . 4
5.1 Tests applicable to panel construction . 4
5.2 Tests applicable to wall panels . 4
6 Structural testing . 4
6.1 Conditioning . 4
6.2 Tensile test on core material and bonding between faces and core . 4
6.3 Shear test on panel assembly (short-term loading) . 7
6.4 Accelerated ageing tests . 9
6.5 Vertical load capacity (stiffness and strength) . 10
6.6 Bending properties for SIP headers (stiffness and strength) . 14
6.7 Horizontal in-plane monotonic load racking stiffness and strength test . 16
6.8 Out-of-plane bending (stiffness and strength) . 21
Annex A (informative) Testing for creep by means of ASTM C480. 24
Bibliography . 27
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ISO 22452:2011(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 22452 was prepared by Technical Committee ISO/TC 165, Timber structures.
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ISO 22452:2011(E)
Introduction
The objective of this International Standard is to provide the means for the structural testing of structural
insulated panel (SIP) walls.
It includes tests for tensile bonding strength of the panels, ageing, shear, vertical load performance, horizontal
in-plane performance and out-of-plane bending performance. A creep test has been included in the annex for
information (and trial). The tests applicable to panels for particular applications are presented, the test
requirements, including laboratory conditions, are given and the numbers of samples to be tested and the
reporting of results are specified.
This International Standard is not intended for quality control testing or for conformity assessment.
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INTERNATIONAL STANDARD ISO 22452:2011(E)
Timber structures — Structural insulated panel walls —
Test methods
1 Scope
This International Standard specifies test methods for determining the structural properties of double-sided,
wood-based, load-bearing structural insulated panels (SIPs) for use in walls.
It is applicable to SIPs having
two face layers, at least one of which is a wood-based structural panel, and
a core made of a thermally insulating material having sufficient shear strength to cause the face layers to
act together structurally.
NOTE 1 Gypsum-based structural boards are commonly used as a face layer.
NOTE 2 Panels can contain internal framing or bracing.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ASTM C393/C393M-06, Standard Test Method for Core Shear Properties of Sandwich Constructions by
Beam Flexure
ASTM D7446-09, Standard Specification for Structural Insulated Panel (SIP) Adhesives for Laminating
Oriented Strand Board (OSB) to Rigid Cellular Polystyrene Thermal Insulation Core Materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
structural insulated panel
SIP
panel with two load-bearing skins, one bonded to each face of a rigid, lightweight, homogenous core material
with sufficient shear strength to cause the face layers to act together structurally
See Figure 1.
NOTE The homogenous core is made of one material with no internal joints requiring bonding.
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ISO 22452:2011(E)
Key
1 rigid core
Figure 1 — Cross-section of structural insulated panel
3.2
double-skin box with structural core-type structural insulated panel
panel with a rigid core surrounded by a structural frame, with or without internal ribs, and two skins
mechanically fastened and/or bonded to the frame and core, forming a closed box
See Figure 2.
NOTE The skins, core and frame are all load-bearing.
Key
1 core
2 internal structural frame
Figure 2 — Structural insulated panel with internal structural frame
3.3
slabstock
core material which is pre-formed into slabs of thickness equal to the required depth of the core and then
bonded with a suitable adhesive
NOTE The length and width of a slab of core material are less than or equal to the length and width of the SIP.
3.4
bonded
condition of components of a structural insulated panel in which they are bonded to each other by adhesive or
where foams used for cores are foamed in situ and become self-adhesive while expanding and curing so that
they bond automatically to the enveloping components
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ISO 22452:2011(E)
4 Symbols
a, b, c distances, in millimetres (mm)
B width of full panel, in millimetres (mm)
F load, in newtons (N)
F maximum load, in newtons (N)
max
F ultimate load, in newtons (N)
u
F estimated maximum load, in newtons (N)
max,est
F vertical load, in newtons (N)
v
D panel thickness, in millimetres (mm)
F self load of loading element, in newtons (N)
g
F self load of panel, in newtons (N)
g1
F applied permanent load, in newtons (N)
g2
F lever arm load, in newtons (N)
l
F loading plate and rod load, in newtons (N)
p
F variable load, in newtons (N)
Q
H height of full panel, in millimetres (mm)
L span, in millimetres (mm)
l length of panel sample, in millimetres (mm)
R stiffness, in newtons per millimetre (N/mm); strength, in newtons per millimetre (N/mm)
T loading time, in seconds (s)
T recovery time, in seconds (s)
r
b width of panel sample, in millimetres (mm)
d depth (thickness) of core, in millimetres (mm)
c
e depth between the centroids of the faces, in millimetres (mm)
2
f tensile strength of core material, in newtons per square millimetre (N/mm )
ct
2
f shear strength of core material, in newtons per square millimetre (N/mm )
cv
t , t overall thickness of the face in millimetres (mm)
1 2
w deformations, in millimetres (mm)
w total deflection under constant load at time t, in millimetres (mm)
t
w initial static deflection under constant load and temperature, in millimetres (mm)
0
factor of less than unity modifying F
max,est
panel racking deformation, in millimetres (mm)
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ISO 22452:2011(E)
5 Product evaluation
5.1 Tests applicable to panel construction
The following test regimes are applicable to the panel construction:
a) tensile testing on the core and its bonding to faces;
b) ageing test;
c) shear strength of the solid core and its bonding to faces.
5.2 Tests applicable to wall panels
The following test regimes are applicable to the wall panel:
a) vertical load (stiffness and strength);
b) horizontal in-plane load (racking stiffness and strength);
c) out-of-plane bending (stiffness and strength).
6 Structural testing
6.1 Conditioning
6.1.1 Standard conditioning
Where standard conditioning is required for the tests specified in 6.2 to 6.8, the test pieces used shall be
conditioned to constant mass in an atmosphere of relative humidity of (65 5) % and temperature of
(20 2) °C. Constant mass is deemed to be attained when the results of at least three successive weighings
indicate that the moisture content has stabilized to within 0,5 % for at least a 48 h period.
If the conditions of the testing room are not the same as those in the conditioning chamber, the test pieces
shall remain in the conditioning chamber until testing.
6.1.2 Alternative conditionings
Where test pieces are not conditioned or are conditioned differently from the procedure given in 6.1.1, the
alternative shall be described in the test report.
When required or appropriate, results may be corrected to reflect conditioning according to 6.1.1. The
procedure for adjusting structural properties shall be technically sound and shall be recorded in the test report.
6.2 Tensile test on core material and bonding between faces and core
6.2.1 Specimen size and sampling
The depth of the specimen shall be equal to the panel thickness, D. The width, b, shall be 150 mm and the
length, l, shall be 150 mm (see Figure 3).
NOTE The purpose of this test is to determine the critical failure mechanism, in core or glue line of the SIP.
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ISO 22452:2011(E)
The test specimens should be sampled from a range of positions covering the width and length of the panel,
including the centre and edge of the sampling area, shown in Figure 3. The outer 10 % of the panel perimeter
is excluded from testing.
Key
1 sampling area
b panel width
l panel length
Figure 3 — Specimen sampling from panel
6.2.2 Conditioning
Specimens shall be conditioned either in accordance with 6.1 or to a specified elevated temperature.
Specimens shall be tested immediately after removal from the conditioning chamber when performing an
elevated temperature test.
Testing at an elevated temperature may be appropriate for certain applications, and performance of the panel
unit should be verified at these conditions. If uncertain of in-service temperature levels, elevated temperature
test specimens should be conditioned at 80 °C for at least 4 h. No further temperature measurement is
required after conditioning.
6.2.3 Loading method and test procedure
Specimens shall be bonded, using a suitable adhesive, to platens of sufficient stiffness to ensure a uniform
tensile stress over the area of specimen. When conditioned according to 6.1, platens shall be bonded to the
specimen after conditioning. Specimens of square cross-section shall be prepared in accordance with
Figure 4.
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ISO 22452:2011(E)
Key
1 core
2 panel face
3 load-distributing platen
Figure 4 — Test arrangements in core tension test
The load, F, shall be applied in increments or continuously so as to reach maximum load in a period of 1 min
to 5 min.
For SIPs with OSB (oriented strand board) and polystyrene thermal insulation core materials,
ASTM D7446-09, 13.2, should be referred to and considered for use, as appropriate.
NOTE This test is not intended for paper-faced lining materials.
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ISO 22452:2011(E)
6.2.4 Reporting results
The tensile strength, f , of the core material shall be calculated from the maximum load attained in a
ct
specimen failing in tension as follows:
F
u
f
ct
bl
where F is the ultimate load carried by the specimen failing in tension.
u
The test report shall include the following information:
a) sampling procedure;
b) number of specimens tested;
c) specification for the test panels;
d) specification of the materials used in the manufacture of the test panels;
e) detailed description of the test specimens, including any deviations from the specification;
f) type of any failure, stating whether failure was in adhesion, cohesion or another mode; failure of the bond
between board face and loading platen should be recorded separately;
g) any conditioning applied to the specimens, and the test laboratory conditions;
h) the tensile strength, f , of each specimen and the mean of all test results;
ct
i) any other appropriate information.
NOTE If failure occurs at bond, then the f value is quoted as the default.
ct
6.3 Shear test on panel assembly (short-term loading)
6.3.1 General
This test shall be applied to SIPs with no additional internal frames. The behaviour of panels with internal
frames or internal ribs shall be established from the out-of-plane bending test (see 6.8). Specimens shall be
conditioned in accordance with 6.1.
6.3.2 Specimen size and sampling
The specimen (1 000 mm 150mm) shall be cut from full-sized SIPs (single-panel units before
assembly/jointing, often 1,2 m 2,4 m).
The test specimens should be sampled from a range of positions covering the width and length of the panel,
including the centre and edge of the sampling area shown in Figure 3. The outer 10 % of the panel perimeter
is excluded from testing.
If the 1 000 mm span does not result in a shear failure in the first test, the span shall be reduced in increments
of 100 mm in subsequent tests until shear failure is obtained. Subsequent tests shall then be carried out at the
reduced span.
NOTE The intent is to induce a shear failure in the specimen.
6.3.3 Loading method and test procedure
The load, F, shall be applied equally at the 1/3 points of the span between the supports (see Figure 5). Apply the
load until failure occurs. The loading rate shall be such as to result in failure between 1 min and 5 min after the
start of the test. If the SIP has two dissimilar faces, the weaker of the two faces shall be placed in compression.
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ISO 22452:2011(E)
Figure 5 — Test arrangement in shear test on SIP (no internal frame)
The metal strips or similar at the supports and load points shall equal the specimen width plus 50 mm in
length, 50 mm in width and 15 mm in thickness. If local crushing of the core occurs in the first test, increase
the width until crushing is prevented. See Figure 6.
NOTE The radius of the ball bearings are typically in the range of 15 mm.
Key
1 core
t , t panel faces
1 2
Figure 6 — Cross-section of shear test specimen
The loading rate shall be such as to result in failure between 1 min and 5 min after the start of the test and
shall be monitored by specimen deflection.
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ISO 22452:2011(E)
6.3.4 Reporting results
For each test specimen, measure depths D and d , width b and the net face thicknesses, t and t , of both
c 1 2
panel faces of each test specimen.
Calculate the shear strength, f , of the core material from the maximum load attained in a specimen failing in
cv
shear as follows:
F
u
f
cv
2be
where F is the ultimate load carried by the specimen failing in shear.
u
The test report shall include the following information:
a) sampling procedure;
b) number of specimens tested;
c) specification for the test panels;
d) specification of the materials used in the manufacture of the test panels;
e) detailed description of the test specimens and set-up, including any deviations from the specification;
f) direction of greater strength of the facing material, if applicable;
g) type and position of any failure;
h) any conditioning applied to the specimens, and the test laboratory conditions;
i) shear strength, f , of the core material for each specimen, and the mean of all tests;
cv
j) any other appropriate information.
6.4 Accelerated ageing tests
Conduct the dry soak test and modified D1183 C tests in accordance with ASTM D7446-09, Section 14, with a
minimum of five specimens.
Subject each specimen to six complete cycles of laboratory ageing.
After completion of the six cycles of exposure, further condition the specimen at a temperature of (20 2) °C
and relative humidity of (50 2) % back to a constant weight (0,5 %) before testing. Report the time required
to attain constant weight.
The specimen shall be frequently inspected during the ageing cycles for any signs of delamination or other
disintegration. If there is any apparent damage to the material, report the damage and the stage of the regime
in which it appeared.
After completion of the cycles, subject the specimens to the following tests:
tensile test (see 6.2);
shear test (see 6.3).
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ISO 22452:2011(E)
6.5 Vertical load capacity (stiffness and strength)
6.5.1 Specimen size and sampling
Panels shall be tested individually. They shall be of sizes typical in service, and of formats for which structural
design data is required. Specimens shall be conditioned in accordance with 6.1.
6.5.2 Loading method and test procedure
6.5.2.1 General
In-service installation details and top- and bottom-support conditions shall be simulated. The test loading shall
be both applied and resisted in a manner approximating the actual in-service conditions. The specimen shall
be loaded either concentrically (see Figure 7) or eccentrically (see Figure 8). The eccentricity shall be at least
one-sixth the panel thickness to the interior or towards the weaker facing of material of an interior panel.
Eccentricities other than those necessary to simulate in-service conditions shall be avoided at points of
loading and reaction, and care shall be taken to ensure that no inadvertent restraints are present. If
eccentricities in the service conditions are larger, they shall be used in testing.
Key
1 solid base
2 load spreader
NOTE Top and bottom rail configurations to match in-service conditions.
Figure 7 — General test set-up for vertical load capacity
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ISO 22452:2011(E)
Alternative panel sizes may be tested if required.
A minimum of three, ideally five, identical panels or assemblies of the same design should be tested.
It might be appropriate to cover the impact of the inclusion of pre-cut conduits or electrical boxes. These can
control the capacity of the SIP and should be considered when testing.
Figure 7 illustrates a typical test set-up for measuring vertical load capacity for a concentrically applied load.
Deflection shall be measured at mid-point and mid-height to monitor out-of-plane deformations, and at the top
of the panel to monitor in-plane compression.
Key
1 solid base
2 load spreader
NOTE Top and bottom rail configurations to match in-service conditions.
Figure 8 — General test set-up for eccentric vertical loading conditions
The accuracy of loading and of deflection and load measurement shall be within 3 %. Departures from the
required test procedure and values shall be reported.
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ISO 22452:2011(E)
6.5.2.2 Basic loading procedure
The basic loading procedure shall consist of the procedural steps (0–7) given in Table 1. A diagrammatic
representation of the loading procedure is given in Figure 9.
It is strongly recommended that a vertical preload of 5 kN be applied and maintained for 120 s, then released.
Allow the panel to recover for a minimum of 300 s before starting the test.
Table 1 — Basic loading procedure
Time
Procedural step Loading procedure
s
0 Only F acting, and F 0 —
g1
0–1 Apply F F —
g2
1–2 Maintain F F 120
g2
2–3 Apply F F 0,5F 120
g2 Q
3–4 Remove 0,5F 120
Q
4–5 Apply F F F 240
g2 Q
5–6 Maintain F F F 1 200
g2 Q
a
6–7 Increase F until F is reached 600
max,est
a
The maximum loading rate shall not exceed 0,25F per 60 s.
Q
Key
T time
F load
Figure 9 — Schematic of loading procedure
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ISO 22452:2011(E)
6.5.2.3 Maximum load — Procedure 1
Procedure 1 shall consist of the basic loading steps (0–7), concluded by increasing the load up to the
maximum load, F , (step 7–8), as shown in Figure 9.
max
If considerable deformation occurs during the application of the load, the rate of loading should be reduced.
6.5.2.4 Proof loading — Procedure 2
Procedure 2 shall consist of the basic loading steps (0–7). The load shall be removed after a prescribed load,
F ( 1), has been reached and the test ended (steps 7–9), as shown in Figure 9.
max,est
NOTE This procedure is intended for proof loading and where the capacity at more than one load combination is
tested. The value of depends on the confidence required in estimating the maximum load capacity. Typically, ranges
between 60 % and 80 % of F . This can be adjusted in subsequent tests.
max
6.5.2.5 Long-term deformation — Procedure 3
Procedure 3 shall consist of the basic loading steps (0–7). The load, F , shall be kept constant for a
max,est
chosen period of time, T, and then removed and the recovery measured during a chosen period, T ,
r
(steps 7–12), as shown in Figure 9.
6.5.2.6 Capacity after long-term loading — Procedure 4
This is the same as procedure 3 except that the structure shall be reloaded to failure (steps 7–13), as shown
in Figure 9.
NOTE Whereas procedure 3 is intended for the study of deformation under long-term loading, procedure 4 is
intended for the study of maximum load capacity after long-term loading.
6.5.3 Instrumentation and data recording
Deformation (e.g. deflection) shall be measured at the number of locations necessary for estimating the
performance of the structure. At a minimum, the deformation shall be measured at the point of expected
maximum deformation.
At a minimum, the load and deformation shall be recorded at each load application or removal, i.e. at the
points marked by circles in Figure 9, and, additionally, at loading increments of above 0,1F .
max,est
During constant load, time and deformation shall be recorded continuously or, where this is not possible, at
least five times during the period of constant load (three points between the starting and final points).
NOTE In-plane deformation is only critical for compression, crushing-type failure, which is not specifically evaluated
with this test regime.
Measurements of load and deformation should be recorded continuously.
6.5.4 Reporting results
The test report shall include the following information:
a) number of panels tested;
b) specification of the test panels;
c) specification of the materials used in the manufacture of the test panels;
d) specification of any mechanical fasteners (including corrosion protection), and their quantity and
positioning;
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ISO 22452:2011(E)
e) detailed description of the test panels, including any deviations from the specification;
f) any gaps within the test specimen;
g) direction of greater strength of the facing material, if applicable;
h) description of the fixings of the panel to the test rig;
i) description of the method of loading the panel and of measuring the panel deformations;
j) test loads attained during the tests, together with the corresponding deformations at all measurement
positions and the application points, load/deformation curves and deformation/time curves;
k) type and position of any failure;
l) any conditioning applied to the panel, and the test laboratory conditions;
m) any other appropriate information.
6.6 Bending properties for SIP headers (stiffness and strength)
6.6.1 General
Bending tests shall be conducted for structural insulated panels used as window or door headers.
The SIP headers are normally cut out from large panels along the strength axis of the facing materials. SIP
headers are typically fabricated with solid timber splines attached to the top and bottom of the header with
nails. The units are generally loaded edgewise, with the load being transferred parallel to the plane of the
facing materials and perpendicular to the strength axis of the facing materials. Due to the complexity of the
available material and connection combinations, the bending properties of SIP headers should be evaluated
based on the full-scale testing described in the following subclauses using representative specimens and
details recommended by the SIP manufacturer. Other proprietary header systems used for SIP construction
can also be tested using this method.
NOTE Depending on the span-to-depth ratio of the header, the thickness and properties of the facing materials and
the connection details between the facing materials and the spline set-up, the failure mode of SIP headers could range
from flexural failure to shear failure of the facing materials, shear failure along the connection, flexure failure of the timber
tension spline and bearing failure of the facing materials.
6.6.2 Specimen size and sampling
Specimen size shall be determined in accordance with the intended applications. The specimen size shall
include the minimum and maximum thicknesses and depths, and the maximum, minimum and intermediate
lengths intended for the header applications.
The long edges of each specimen shall be assembled from a SIP and fixed as recommended by the SIP
manufacturer to produce the test header unit. If finger-jointed splines are used, at least one finger joint shall
be located near the centre of the test span on the tension side of the specimen.
Specimens shall be conditioned in accordance with 6.1.
6.6.3 Loading method and test procedure
The specimen shall be set up in accordance with Figure 10 and the load, F, shall be applied equally at the
1/3 points of the span between the supports. Apply the load until failure occurs. The loading rate shall be such
as to result in failure between 1 min and 5 min after the start of the test. Deflection shall be m
...
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