U.S. patent application number 11/825870 was filed with the patent office on 2008-01-31 for fiber-cement/gypsum laminate.
Invention is credited to Mark T. Fisher, James A. Gleeson, Donald J. Merkley.
Application Number | 20080022627 11/825870 |
Document ID | / |
Family ID | 22568886 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080022627 |
Kind Code |
A1 |
Gleeson; James A. ; et
al. |
January 31, 2008 |
Fiber-cement/gypsum laminate
Abstract
A building material (40) is provided comprising fiber-cement
(10) laminated to gypsum (20) to form a single piece laminate
composite. This single piece laminate composite exhibits improved
fire resistance and surface abuse and impact resistance, but
achieves these properties without the excessive weight and
thickness of two piece systems. Additionally, because of the
reduced thickness, the preferred laminate building material is
easier to cut and is quicker and easier to install than two piece
systems. Furthermore, forming the fiber-cement and gypsum into a
single piece laminate eliminates the need to install two separate
pieces of building material, thereby simplifying installation. In
one embodiment, a 5/8'' thick laminate composite is provided
comprising a 1/2'' thick gypsum panel laminated to a 1/8'' thick
fiber-cement sheet, the laminate composite having a fire resistance
rating of 1 hour when measured in accordance with ASTM E119.
Inventors: |
Gleeson; James A.; (Upland,
CA) ; Fisher; Mark T.; (Huntington Beach, CA)
; Merkley; Donald J.; (Alta Loma, CA) |
Correspondence
Address: |
GARDERE / JAMES HARDIE;GARDERE WYNNE SEWELL, LLP
1601 ELM STREET
SUITE 3000
DALLAS
TX
75201
US
|
Family ID: |
22568886 |
Appl. No.: |
11/825870 |
Filed: |
July 10, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11125813 |
May 9, 2005 |
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11825870 |
Jul 10, 2007 |
|
|
|
10437344 |
May 13, 2003 |
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11125813 |
May 9, 2005 |
|
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|
09685637 |
Oct 10, 2000 |
6562444 |
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10437344 |
May 13, 2003 |
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60158600 |
Oct 8, 1999 |
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Current U.S.
Class: |
52/745.19 |
Current CPC
Class: |
E04C 2/049 20130101;
B32B 7/02 20130101; Y10T 428/2904 20150115; B32B 27/10 20130101;
Y02W 30/91 20150501; B32B 13/08 20130101; B32B 13/00 20130101; B32B
13/14 20130101; B32B 29/00 20130101; B32B 2329/00 20130101; B32B
7/12 20130101; Y10T 428/26 20150115; B32B 29/02 20130101; C04B
28/02 20130101; B32B 27/06 20130101; B32B 2419/00 20130101; Y10T
428/249932 20150401; B32B 13/02 20130101; Y10T 428/24959 20150115;
E04C 2/043 20130101; Y10T 428/2913 20150115; B32B 2307/3065
20130101; C04B 2111/0062 20130101; B32B 27/02 20130101; Y10T
428/249967 20150401; C04B 28/02 20130101; C04B 18/241 20130101;
C04B 41/5085 20130101 |
Class at
Publication: |
052/745.19 |
International
Class: |
E04F 13/02 20060101
E04F013/02 |
Claims
1-11. (canceled)
12. A method for manufacturing a composite building material
comprising: applying an adhesive to a face of a gypsum layer; and
laminating a fiber cement layer to the adhesive.
13. The method of claim 12, wherein the gypsum layer is about 1/2''
thick.
14. The method of claim 12, wherein the gypsum layer is a type X
fire resistant gypsum board.
15. The method of claim 12, wherein the fiber cement layer is about
1/8'' thick.
16. The method of claim 12, wherein the fiber cement layer is a
pre-fabricated fiber cement sheet.
17. The method of claim 12, wherein the fiber cement layer
comprises cellulose fiber
18. The method of claim 12, further comprising sanding the fiber
cement layer.
19. The method of claim 12, wherein the laminating comprises
pressing the gypsum layer and fiber cement layer together.
20. The method of claim 12, wherein the adhesive is selected from
the group consisting of organic adhesives, inorganic adhesives,
polyvinyl acetate, water-based polymeric adhesives, solvent-based
adhesives, thermoset adhesives, natural polymers, modified
starches, liquid moisture cure adhesives, reactive hot melt
adhesives, polyurethane, heat or fire resistant adhesives, pressure
sensitive adhesives, and combinations thereof.
21. The method of claim 12, wherein the adhesive is applied by a
roll-coater process.
22. The method of claim 12, wherein the adhesive has a wet film
thickness of from about 4.5 mil to about 6 mil.
23. The method of claim 12, further comprising tapering an edge of
the composite building panel.
24. The method of claim 12, further comprising sealing the surface
of the composite building panel.
25. The method of claim 24, wherein at least the fiber cement
surface of the composite building panel is sealed with an acrylic
sealer.
26. The method of claim 12, wherein the composite building material
has a fire resistance rating of at least an hour according to ASTM
E 119-98.
Description
[0001] This application is a continuation of prior U.S. application
Ser. No. 10/437,344, filed May 13, 2003 which is a continuation of
09/685,637, filed Oct. 10, 2000, now U.S. Letters Pat. No.
6,562,444, and also claims the benefit of Provisional Application
Ser. No. 60/158,600, filed Oct. 8, 1999, all of which are hereby
incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to abuse resistant, impact resistant
and fire resistant building materials, and more particularly, to a
single piece laminate composite building material of fiber-cement
and gypsum.
[0004] 2. Description of the Related Art
[0005] The interior wallboard market has been dominated by the use
of gypsum wallboard products for many years. The gypsum wallboard
typically comprises thin paper layers wrapped around a gypsum core.
For example, one paper layer covers the face and long edges of the
board, and the second paper layer usually covers the back surface
of the board. The core is predominantly gypsum, and can be modified
with additives such as glass fiber, vermiculite and mica to improve
fire resistance.
[0006] In addition to fire resistance, abuse resistance is another
desired quality in wallboards. Gypsum has poor abuse resistance
compared to other wallboard materials such as wood or masonry. The
paper surface of gypsum wallboard is easily damaged by impact such
as scuffing, indentation, cracking or penetration with hard or soft
body objects such as furniture, trolleys, toys, sports equipment
and other industrial or residential furnishings. Such wall abuse is
typical in high traffic rooms such as corridors, family living
areas, gymnasiums or change rooms.
[0007] Gypsum wallboard manufacturers have made modifications to
their gypsum wallboards to improve their abuse resistance. One
method was to bond a plastic film to the back of the wall panel to
resist penetration of the impact bodies into the framed wall
cavity. Another method was to make a fiber-gypsum wall panel with
fiber-gypsum outer layers formed onto a gypsum-based core. These
products typically have improved surface abuse resistance to the
paper surface of normal gypsum wallboard. Similar gypsum-based or
cement gypsum-based compositions are typically described in U.S.
Pat. No. 5,817,262 and U.S. Pat. No. 5,718,759.
[0008] One material having significant abuse resistance is
fiber-cement. Fiber cement has an advantage over gypsum panel with
respect to surface abuse resistance such as wear and abrasion. One
disadvantage of fiber cement by itself as a wall panel is that it
does not have a fire resistance rating comparable to gypsum wall
panels of equal thickness. Another disadvantage of fiber cement by
itself is that it is significantly heavier than gypsum wall panels
of equivalent thickness. For example, a 1 hour fire
resistance-rated wall system with fiber cement requires mineral
insulation in the wall cavity or a sub-layer of fire rated gypsum
wall panel to achieve a 1 hour fire resistance rating when tested
in accordance with ASTM E-119.
[0009] A 2-layer system of 1/4'' fiber cement over 5/8'' type X
fire rated gypsum wallboard has been used to achieve both fire
resistance and abuse resistance. Such a system is described in
Gypsum Association--Fire Resistance Design Manual--GA FILE NO. WP
1295--Gypsum wallboard, steel studs, fiber-cement board proprietary
system. This two piece system is disadvantageous because it is
significantly heavier than single-layer gypsum wallboards.
Additionally, the 2-layer wallboards require nearly double the
amount of labor for installation because two separate wall panels
must be installed instead of a single panel. Also, the extra
thickness of the 2-layer systems (5/8''+1/4''=7/8'') is not
compatible with most door jamb widths.
SUMMARY OF THE INVENTION
[0010] Accordingly, what is needed is a single piece building
material that has good abuse resistance, impact resistance and fire
resistance. This building material should also be light, easy to
manufacture and compatible with standard building material sizes.
With respect to fire resistance, it would be especially
advantageous for such a material to have a fire resistance rating
of at least one hour as measured by ASTM E119.
[0011] Briefly stated, the needs addressed above are satisfied in
one embodiment by a building material comprising fiber-cement
laminated to gypsum to form a single piece laminate composite. This
single piece laminate composite exhibits improved fire resistance
and surface abuse resistance, but achieves these properties without
the excessive weight and thickness of two piece systems.
Additionally, because of the reduced thickness, the preferred
laminate building material is easier to cut and is quicker and
easier to install than two piece systems. Furthermore, forming the
fiber-cement and gypsum into a single piece laminate eliminates the
need to install two separate pieces of building material, thereby
simplifying installation.
[0012] One object of the invention is to provide a building board
product suitable for applications requiring surface abuse
resistance, improved impact resistance and a 1-hour fire resistance
rating (as measured, for example, by ASTM E-119) without cavity
insulation at a panel thickness of 5/8'', installed on each side of
a wall frame. The surface abuse resistance is measured by abrasion
tests such as ASTM D4977-98b (Standard Test Method for Granule
Adhesion to Mineral Surfaced Roofing) and also indentation tests
such as ASTM D5420 (Impact Resistance of Flat, Rigid Plastic
Specimen by Means of a Striker by a Falling Weight (Gardner
Impact)). The panel impact resistance is typically measured by, for
example, ASTM E695 (Measuring Relative Resistance of Wall, Floor
and Roof Construction to Impact Loading), and ISO 7892 (Vertical
Building Elements--Impact Resistance Tests--Impact Bodies and
General Test Procedures), or other suitable impact or abrasion
tests.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of a single piece laminate
composite comprising fiber-cement laminated to gypsum.
[0014] FIG. 2 is a cross-sectional view of the single piece
laminate composite of FIG. 1, showing the fiber-cement and gypsum
adhered together using an adhesive.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] The preferred embodiments of the present invention
illustrated below describe a single piece laminate composite
wallboard system. It will be appreciated, however, that the present
invention is not limited to wallboards, but can be utilized for any
application where an abuse resistant, impact resistant and fire
resistant building material is desired.
[0016] As seen in FIG. 1, a preferred building material 40 is
comprised of a fiber-cement layer 10 laminated to gypsum layer 20,
creating a single piece laminate composite. FIG. 2 illustrates that
the fiber cement layer 10 may be laminated to the gypsum layer 20
using an adhesive 30, the thickness of which is exaggerated in FIG.
2 for illustration purposes, as described in further detail below.
It will be appreciated that the fiber-cement and gypsum components
can take any form necessary, including, but not limited to, panels,
sheets, skins, boards, or the like. In one preferred embodiment,
the thickness of a fiber-cement sheet 10 is between about 1/32''
and 1/4''. More preferably, the fiber-cement sheet 10 is about
1/8'' thick, plus or minus about 1/16''. A gypsum panel 20
typically has a thickness between about 1/4'' to 3/4'', more
preferably about 1/2''. It will be appreciated that other
thicknesses for the fiber-cement sheet 10 and the gypsum panel 20
may be used. The preferred weight is about 2.5 to 3 lbs/square
foot, more preferably about 2.77 lbs/square foot for a 5/8'' thick
composite wallboard.
[0017] One preferred embodiment of the invention is a composite
panel that is manufactured by bonding together a paper-faced 1/2''
type X gypsum wallboard to 1/8'' thick fiber cement panel. ASTM C
36 describes a type X gypsum board to have not less than 45 minutes
fire resistance rating for boards 1/2'' thick, applied parallel
with and on each side of load bearing 2''.times.4'' wood studs
spaced 16'' on center with 6D coated nail, 17/8'' long 0.095''
diameter shank, 1/4'' diameter head, spaced 7'' on center with the
gypsum joints staggered 16'' on each side of the partition and
tested in accordance with ASTM E 119. One preferred 1/2'' Type X
gypsum panel is a 1/2'' thick HARDIROCK.RTM. MAX "C".TM., described
in the table below. This gypsum panel has an improved Type X fire
resistance rated core and is manufactured for commercial projects
where building codes require specific levels of fire resistance and
sound reduction. The 5/8'' thick board is designed to provide
greater fire resistance than standard Fire X.TM. board and achieves
fire and sound rating with less weight. Application information is
available in the Gypsum Association Fire Resistance Design Manual
GA-600, Underwriter's Laboratories, Inc. Fire Resistance Directory.
TABLE-US-00001 HARDIROCK .RTM. MAX "C" .TM. THICKNESS 1/2'' (12.7
mm) inches (mm) WIDTH 4' (1219 mm) feet (mm) STANDARD LENGTHS 8',
9', 10' feet STANDARD EDGES Tapered or square APPROX WEIGHT 1.8
lbs/sq ft (8.8 kg/m.sup.2) lbs/sq ft (kg/m.sup.2) ASTM SPECS C
36
[0018] It will be appreciated that the face of the gypsum panel 20
bonded to the fiber-cement 10 does not necessarily require a paper
face, and the gypsum panel 20 may be bonded directly to the
fiber-cement 10. A preferred gypsum panel 20 may also have a glass
or polymeric fiber mat or woven mesh combined into the panel on
either the front or back surface, either on the outside or the
inside of the paper. This can be done for two reasons. First, it
can be used to improve the impact resistance of the gypsum panel 20
by itself. Second, it can be used to improve the impact resistance
of the gypsum panel as part of the composite wallboard 40.
[0019] The preferred composite wallboard 40 can be utilized in most
interior wallboard installations. The preferred composite wallboard
40 is installed such that the fiber-cement side of the wallboard 40
faces outward to provide an abrasion and indentation resistant
surface to traffic, and the gypsum side of the wallboard 40 is
installed against the supporting framing, with the synergistic
combination of the fiber-cement and the gypsum wallboard providing
the fire resistance rating and strength of the panel. Neither the
preferably 1/2'' gypsum panel 20 nor the preferably 1/8''
fiber-cement sheet 10 provides the 1-hour fire resistance rating in
isolation, but rather the combination of the two materials in a
laminated composite 40 has been tested in a symmetrical wall system
and achieved a 1 hour fire resistance rating on a typical steel
framing used in commercial building partitions. Results of a fire
resistance test conducted on this composite panel are provided
below.
[0020] The supporting framing is typically 20 or 25 gauge steel
framing, or wood framing such as 2''.times.4'' Douglas Fir
softwood. The wallboard 40 can be fastened to the steel studs with
suitable screws such as 6 gauge.times.11/8'' Type S Bugle Head
drywall or self-drilling screws. The wallboard 40 can be fastened
to wood studs with suitable nails or screws such as 13/4'' long
cup-head gypsum wallboard nails or 6 gauge.times.11/8'' Type S
Bugle Head drywall screws. The preferred wallboard 40 is designed
for use in wall assemblies that are subject to surface abuse and
penetration. Such wall assemblies are typically found in schools,
public housing, public buildings, interior garage walls, corridors,
gymnasiums, change rooms, and correctional and healthcare
facilities. The material can be cut with a carbide-tipped score and
snap knife, power shears or circular saw optionally with dust
control.
Fiber Cement
[0021] The art of manufacturing cellulose fiber reinforced cement
for use in a fiber-cement sheet or skin 10 is described in the
Australian Patent AU 515151 and U.S. Pat. No. 6,030,447, the
entirety of which is incorporated by reference. Fiber cement has
the attributes of durability, resistance to moisture damage, low
maintenance, resistance to cracking, rotting or delamination,
resistance to termites and non-combustibility. Thus, the fiber
cement layer 10 resists damage from extended exposure to humidity,
rain, snow, salt air and termites. The layer is dimensionally
stable and under normal conditions will not crack, rot or
delaminate.
[0022] The basic composition of a preferred fiber-cement panel 10
is about 20% to 60% Portland cement, about 20% to 70% ground silica
sand, about 5% to 12% cellulose fiber, and about 0% to 6% select
additives such as mineral oxides, mineral hydroxides and water.
Platelet or fibrous additives, such as, for example, wollastonite,
mica, glass fiber or mineral fiber, may be added to improve the
thermal stability of the fiber-cement.
[0023] The dry density of a preferred fiber-cement panel 10 is
typically about 1.3 to 1.4 g/cm.sup.3 but can be modified by
pressing the material to dry densities up to 2.0 g/cm.sup.3 or by
addition of density modifiers such as unexpanded or expanded
vermiculite, perlite, clay, shale or low bulk density (about 0.06
to 0.7 g/cm.sup.3) calcium silicate hydrates.
[0024] The flexural strength of a preferred fiber-cement panel 10,
typically based on Equilibrium Moisture Content in accordance with
ASTM test method C1185, is 1850 psi along the panel, and 2500 psi
across the panel.
[0025] A preferred fiber-cement panel 10 has a non-combustible
surface and shows no flame support or loss of integrity when tested
in accordance with ASTM test method E136. When tested in accordance
with ASTM test method E84, a preferred fiber-cement panel 10
exhibits the following surface burning capabilities:
[0026] Flame spread: 0
[0027] Fuel Contributed: 0
[0028] Smoke Developed: 5.
Lamination Process
[0029] A preferred panel is comprised of a 1/8'' nominal thickness
fiber cement sheet laminated to a 1/2'' thick type X fire resistant
gypsum board. The gypsum panel is preferably manufactured with
square edges. An adhesive 30 as shown in FIGS. 1 and 2 above such
as polyvinyl acetate (PVA) is spread over the surface of the gypsum
panel and 1/8'' thick fiber cement is placed over the surface and
is typically pressed at about 38 psi, in a stacked configuration,
for approximately 30 minutes. One preferred adhesive is Sun
Adhesives polyvinyl acetate (PVA) adhesive #54-3500 supplied by Sun
Adhesives, a division of Patrick Industries. While the adhesive is
most preferably a low cost adhesive such as PVA, other organic or
inorganic adhesives may be used, such as water-based polymeric
adhesives, solvent-based adhesives, thermoset adhesives, natural
polymers such as modified starches, liquid moisture cure or
reactive hot melt adhesives such as polyurethane, and heat or fire
resistant adhesives.
[0030] The adhesive 30 is preferably applied by a roll-coater
process whereby the gypsum panel 20 is preferably cleaned to remove
dust and debris before the adhesive 30 is applied to the smooth
face. The adhesive 30 is preferably spread evenly over the entire
surface of the gypsum panel 20. The wet film thickness of the
adhesive 30, when measured with a standard "wet film thickness
gauge," will preferably not be less than about 4.5 mil and
preferably will not exceed about 6 mil. The fiber-cement panel 10
is placed on top of the gypsum panel 20, which is coated with
adhesive 30, squared to the edges of the gypsum panel 20, and then
stacked. The completed stack is preferably cured in a press under a
load of about 37.5.+-.2.5 psi for preferably no less than about 30
minutes. The panels then preferably have the fiber cement surface
sanded and the long edges machined with an abrasive wheel such as
diamond grit to form a tapered edge. The machine sanding preferably
utilizes three sanding heads. The grades of sanding belts
preferably range from 40 grit to 220 grit. The long edges are
machine tapered to allow for setting compound, joint reinforcing
tape and finishing compounds during flush jointing on installation.
The surface of the product is preferably sealed with an acrylic
emulsion to reduce the surface water absorption to make it easier
to paint and to improve paint adhesion.
[0031] The fiber-cement surface of the composite wallboard 40 may
be optionally sealed with an acrylic sealer such as UCAR 701 to
facilitate on the job finishing. This can be achieved with a
suitable latex paint which may be sprayed, rolled or brush applied
for wallpaper or texture finishes. It will also be appreciated that
sanding the fiber-cement panel 10 is optional in order to improve
the finish of the fiber-cement surface. Furthermore, it will be
appreciated that sanding can be done before or after the
fiber-cement panel 10 is laminated to the gypsum panel 20. It will
be appreciated that a roll press lamination process may also be
used, with a suitable pressure sensitive adhesive.
Testing
[0032] Abuse resistance tests were conducted on one preferred
laminate composite panel. This preferred panel provided superior
impact resistance to the common type X fire resistant gypsum
wallboard. The preferred panel also has superior abrasion
resistance to both the common type X fire resistant gypsum
wallboard and the abuse resistant gypsum based panels.
[0033] A novel feature of the preferred embodiments of the present
invention is that neither the 1/2'' gypsum wallboard or the 1/8''
fiber cement sheet, by themselves, provide altogether, the 1-hour
fire resistance rating, surface abuse and impact resistance.
However, laminating the two materials together provides the l-hour
fire resistance in a symmetrical wall system when tested to ASTM
E119 and an improved level of surface abuse resistance and impact
resistance.
[0034] It is believed that the preferred panel also has the
advantages of improved flexural strength and nail pull through
strength and less humidified deflection compared to the individual
components of the preferred invention or a typical type X gypsum
wallboard of the same thickness (5/8'' thick).
[0035] The preferred composite also has the novel features of fire
and abuse characteristics in a single wallboard or a single piece
system. Prior fire resistance rated and abuse resistant systems
that utilize fiber cement required a two layer system over the
supporting framework. There is considerable advantage with the
preferred composite in reduced material and quicker installation of
a single piece system versus a 2-layer system. The two layer system
required installation of 5/8'' type X gypsum wallboard followed by
the installation of 1/4'' fiber cement over the top. The total
thickness of these 2 layers adds up to 7/8'' of material versus
5/8'' of material with the preferred laminated composite of the
present invention.
[0036] Thus, in one embodiment the present invention provides a
single piece system that is at least about one hour fire
resistance-rated and abuse resistant. This reduces the amount of
time to install compared to the 2 layer system, lowers the mass of
the wall unit per square foot compared to the 2 layer system, and
requires less fixtures per wall for installing panel compared to
the 2 layer system. Moreover, the material is easily cut with power
shears, which is a quick and easy method of cutting.
[0037] The material also is abrasion resistant, indentation
resistant and impact resistant (soft body and hard body), as
illustrated in the tables below.
[0038] Surface-abuse and impact resistance can be determined by
methods used in such tests as ASTM D 4977-98b (Standard Test Method
for Granule Adhesion to Mineral Surfaced Roofing by Abrasion), ASTM
D 5420 (Impact Resistance of Flat, Rigid Plastic Specimen by Means
of a Striker by a Falling Weight (Gardner Impact)), ASTM E 695
(Measuring Relative Resistance of Wall, Floor and Roof Construction
to Impact Loading), ISO 7892 (Vertical Building Elements--Impact
Resistance Tests--Impact Bodies and General Test Procedures), or
other suitable impact or abrasion tests. Fire resistance can be
measured by tests such as ASTM E 119 (Standard Test Methods for
Fire Tests of Building Construction and Materials), UL263, UBC 7-1,
NFPA 251, ANSI A2.1, or other suitable fire resistance tests. One
5/8'' thick laminate composite embodiment, comprising 1/8''
fiber-cement laminated on top of a 1/2 Hardirock Max "C" Gypsum
panel, achieved superior abrasion and impact resistance as
illustrated in the tables below. TABLE-US-00002 TABLE 1 ASTM D4977
- Wire Brush Surface Abrasion Test (Modified to have a total of 25
lbs load on brush) Abraded Depth Abraded Depth Product (mm)
(inches) 5/8'' laminate composite 0.000 0.000 5/8'' Type X Gypsum
Board 0.016 0.001
[0039] TABLE-US-00003 TABLE 2 ISO 7892 Section 4.3 - Hard
Body/Impact Resistance Test (Single Impact @ 10 ft. Height-22
ft.-lb. force) Indentation Indentation Diameter Depth Product
(inches) (inches) 5/8'' laminated composite 1.270 0.275 5/8'' Type
X Gypsum Board 1.788 0.275
[0040] The hard body impact test was conducted with a 1 kg ball
bearing as outlined in Section 4.3.1 through 4.3.5 of ISO 7892.
[0041] The panels tested were fastened to 20 gauge steel framing
with studs at 16'' on center. The 1/4'' fiber cement panel was
fastened with 7 gauge.times.11/4 C-Drill screw spaced at 8''. The
5/8'' Type X gypsum wallboard was fastened with 6
gauge.times.11/8'' Type S Bugle Head screws spaced at 8'' and the
1/8'' fiber cement laminated on top of 1/2'' Hardirock Max "C"
gypsum wallboard was fastened with 6 gauge.times.11/8'' Type S
Bugle Head screws spaced at 12''. TABLE-US-00004 TABLE 3 ASTM D5420
- Indentation Test/Gardner Impact Test Indentation Product Depth
(inches) 5/8'' laminated composite 0.101 5/8'' Type X Gypsum Board
0.149
[0042] For the indentation test, ASTM D5420-96 Method GC was
followed which specifies a 0.625 mm diameter striker orifice with a
support plate hole close to the diameter of the striker, and a 2
lb. weight falling a distance of 36 inches giving a single energy
impact of (72.+-.1.8) ft.-lbs. Ten specimens were tested from each
product and values in the table have been averaged for all 10.
TABLE-US-00005 TABLE 4 ASTM E695-79 - Soft Body Impact Resistance
Test Cumulative Impact Single Impact Force Force Product (ft.-lbs.)
(ft.-lbs.) 5/8'' laminated composite 180 210 5/8'' Type X Gypsum
Board 60 90 1/4'' Fiber-cement Panel 60 90
[0043] The soft body impacter was fabricated according to the
requirements of sections 5.2.1 through 5.2.4 of E695-79, filled to
a gross weight of 60 lbs. The bag is supported as a pendulum,
striking the panel midway between the stud and mid height of the
test wall in 6'' increments.
[0044] The cumulative impact was defined as the energy needed to
reach "failure mode" either by "set deflection", face/back
cracking, and/or stud deformation of >0.25''. Upon reaching any
of the previously defined failure mode(s), the weighted bag was
raised an additional 6 inches in height to reach the "single impact
energy" needed to reach a failure mode.
[0045] The cumulative impact was defined as the energy needed to
reach "failure mode" either by: "set deflection", and face/back
cracking, and/or stud deformation of >0.25''. Upon reaching any
of the previously defined failure mode(s), the weighted bag was
raised an additional 6 inches in height to reach the "single impact
energy" needed to reach a failure mode.
[0046] The size of the panels was 4'.times.8', and were fastened to
20-gauge steel framing at 24'' on center. The 1/4'' fiber cement
panel was fastened with 7 gauge.times.11/4 C-Drill screw spaced at
8''. The 5/8'' Type X gypsum wallboard was fastened with 6
gauge.times.11/8'' Type S Bugle Head screws spaced at 8'' and the
1/8'' fiber cement laminated on top of 1/2'' Hardirock Max "C"
gypsum wallboard was fastened with 6 gauge.times.11/8'' Type S
Bugle Head screws spaced at 12''.
[0047] Results in the table are an average of 3 panels of each
material tested.
Fire Resistance Testing
[0048] One embodiment of the present invention was tested for fire
resistance according to ASTM E 119-98. This embodiment was tested
as a dual wall assembly, comprising a cold side and hot side. Each
test assembly consisted of a 10 ft.times.10 ft non-loadbearing wall
of 20 GA.times.35/8'' steel studs spaced 24'' o.c. On the cold
side, one layer of 1/8'' thick Hardiboard.RTM. fiber-cement face
skin laminated to 1/2 thick Hardirock.RTM. "Max C".TM. gypsum board
was applied perpendicular (horizontally) to 20 GA..times.35/8''
steel studs 24'' o.c. with minimum 1'' long Type S drywall screws
12'' o.c. at floor and ceiling runners and intermediate studs.
Fasteners were placed approximately 3'' in from panel comers and
approximately 3/8'' in from panel edges. On the fire side, one
layer of 1/8'' thick Hardiboard.RTM. fiber-cement face skin
laminated to 1/2'' thick Hardirock.RTM. "Max C".TM. gypsum board
was applied perpendicular (horizontally) to 20 GA..times.35/8''
steel studs 24'' o.c. with minimum 1'' long Type S drywall screws
12'' o.c. at floor and ceiling runners and intermediate studs. Fire
side horizontal panel joints were offset from cold side horizontal
panel joints by 24''. Fasteners were placed approximately 3'' in
from framing corners and approximately 3/8'' in from panel
edges.
[0049] Framing members in fire-rated wall assemblies are cut 3/4''
shorter than full height of wall thereby creating a floating frame
wall. In order to transport these walls from the fire test facility
to the sound test facility, fasteners were placed through the wall
panels into framing members at floor and ceiling runner tracks to
provide racking resistance to facilitate specimens handling. This
modification does not change the sound transmission characteristics
of the wall assembly.
[0050] Joints were treated with chemically-setting powder gypsum
joint compound (USG.RTM. Durabond.RTM. 90), complying with ASTM
Specification C 475, for flush joining the panel edges.
Setting-type compound was mixed in accordance with manufacturer's
written instructions. Compound was applied to fastener heads and
joint recess was formed by adjoining sheets. Perforated paper
reinforcing tape was immediately imbedded centrally into the
joints. Perforated paper reinforcing tape was immediately imbedded
with additional compound and allowed to dry.
[0051] The ambient temperature at the start of the test was
80.degree. F., with a relative humidity of 84%. Throughout the fire
test, the pressure differential between the inside of the furnace
(measured at a point 1/3 of the way down from the top center of the
wall specimen) and the laboratory ambient air was maintained at
-0.03 inches of water column, which resulted in a neutral pressure
at the top of the test article.
[0052] Observations made during the test were as follows:
TABLE-US-00006 Time (min:sec) Observation 0:00 Furnace fired at
8:52 a.m. 1:43 Applicant's laminated composite panel separating
out-of- plane (OOPS) at top horizontal joint on the fire side 2:20
Surface of Applicant's laminated composite panel cracking and
turning black 3:25 Laminate peeling and falling off exposed surface
4:15 Much of the laminate has fallen away; exposed gypsum paper
flaming 7:13 Gypsum paper black/gray and flaking on fire side 10:30
All of the laminate has fallen off exposed surface 32:30
.about.1/8'' gap at the bottom horizontal joint on the exposed side
39:00 .about.1/2'' OOPS at the bottom horizontal joint near center
of wall on the exposed side. 60:00 The furnace was extinguished and
the test article removed and exposed to the standard hose stream
test. Hose The wall was exposed to the standard hose stream test
Stream for at a pressure of 30 psi from 20 feet away from the
exposed surface for a period of 60 seconds. The test article failed
the hose stream test when the hose stream penetrated the wall after
19 seconds.
[0053] During the fire test, the wall was measured for deflection
at three points along its vertical centerline: at 30'' (position
#1), 60'' (position #2) and 90'' (position #3) from the left side
of the wall. Measurements were made from a taut string to the wall
surface at each location. TABLE-US-00007 TIME Position Position
Position (min) #1 (in.) #2 (in.) #3 (in.) 0 5-3/8 5-3/8 5-1/2 10
5-5/8 5-5/8 5-7/8 20 6-1/4 6-1/2 6-1/2 30 6-3/4 6-3/4 6-7/8 40
6-1/2 6-1/4 6-1/2 50 6-1/4 5-7/8 6-1/4 60 6-1/4 6 6-1/2
Hose Stream Retest
[0054] In accordance with the standard, a duplicate specimen was
subjected to a fire exposure test for a period equal to one half of
that indicated as the resistance period in the fire endurance test,
immediately followed by the hose stream test.
[0055] Observations made during the test were as follows:
TABLE-US-00008 Time (min:sec) Observation 0:00 Furnace fired at
1:37 p.m. 0:53 Applicant's laminated composite panel cracking on
the exposed side 1:20 Applicant's laminated composite panel turning
black 2:40 Gypsum paper turning brown where laminate has fallen off
3:00 Exposed gypsum paper ignited 4:25 Exposed gypsum paper stopped
flaming 11:00 Much of the laminate is gone, gypsum paper turning
white 30:00 The furnace was extinguished and the test article
removed and exposed to the standard hose stream test. Hose The wall
was exposed to the standard hose stream test Stream for 60 seconds
at a pressure of 30 psi from 20 feet away from the exposed surface.
The test article withstood the hose stream test without allowing
passage of water through the wall.
Conclusions from Fire Testing
[0056] The 20 GA., 35/8'' galvanized steel stud wall with
Applicant's laminated composite panels (1/8'' thick Hardiboard.RTM.
fiber-cement face skin laminated to 1/2'' thick Hardirock.RTM. "Max
C".TM. gypsum wallboard) on both surfaces, constructed and tested
as described in this report, achieved a non-loadbearing fire
resistance rating of 60 minutes for a symmetrical wall assembly
according to the ASTM E119 standard.
Summary of Advantages
[0057] The preferred embodiments of the present invention combine
fire resistance of at least 1 hour and significant abuse and impact
resistance in a prefabricated single piece laminate composite
comprising fiber-cement laminated to gypsum. These properties are
achieved in a laminate composite which in one embodiment is only
about 5/8'' thick that is not excessively heavy, is easy to cut and
is quick and easy to install.
[0058] One disadvantage of the two layer systems of the prior art
is that the individual pieces of fiber-cement and gypsum must be
self-supporting in order to facilitate their individual
installation. The layers of fiber-cement and gypsum, therefore, are
limited in how thin they can be in order to remain self-supporting.
The preferred embodiments of the present invention, however,
combine the fiber-cement and gypsum layers into a prefabricated
single piece laminate composite for installation. Thus, the
individuals layers of fiber-cement and gypsum need not be
self-supporting, and the thickness of the fiber-cement layer, for
instance, can be significantly reduced. This reduces the overall
thickness of the single piece laminate composite as compared to the
two piece systems. As a result, one embodiment of the present
invention incorporates a 1/8'' fiber-cement layer and a 1/2''
gypsum layer to create a single piece laminate composite about
5/8'' thick, that simultaneously achieves a one hour fire
resistance rating and abuse and impact resistance.
[0059] The embodiments illustrated and described above are provided
merely as examples of certain preferred embodiments of the present
invention. Various changes and modifications can be made from the
embodiments presented herein by those skilled in the art without
departing from the spirit and scope of the invention.
* * * * *