IE42358B1 - Composite building module - Google Patents

Abstract

PURPOSE: To carry out a welding operation even under a hard-to-manage situation by processing images taken through a welding head during a welding scene with a computer-assisted controlling and processing device in real time and by generating correction values adaptable to the system as necessary. CONSTITUTION: The system is constituted of a welding head 32, welding bench 30 for fixing this head, power feeding means 36, 38 for supplying electricity to the head, and a controlling and processing device 28 that is connected to these head and bench. The head picks up the images of a welding scene as well as recording them, wince the bench moves with respect to the welding scene; the controlling and processing device consists of the central unit, image processor, controller for the power feeding means, and a welding servo. Thus, the functions of the overall welding process can be managed in real time, enabling a welding operation to be performed even under an undesirable environment on conditions uncontrollable by an operator [JPS5185227A]

Description

TATENT APPLICATION BY (71) AMETEX LIMITED, A SWISS COMPANY, OF CH’875O GLARUS, SWITZERLAND.

Prtct I2|p 43358 This Invention relates to a composite building module which is similar to monolithic cast concrete modules in outward appearance and use, yet has significant improvements in insulating properties and weight reduction. More particularly, this invention relates to a composite building module having a rigid foam core, such as a rigid urethane, polymer foam, encased or encapsulated in a shell made of a hardened mixture of cement and fibres, such as glass fibres.

Because of increased costs in material and labor, the construction industry has come to use prefabricated building modules, for example wall panels, roof decks and the like. A popular form of construction is known as '‘curtain-wall'' construction and involves the use of a structural steel skeleton which is faced with stacked-up, prefabricated or precast panels. Such curtain-wall panels are commonly cast from reinforced concrete and are provided with a surface finish such as a smooth concrete finish or aggregate imbedded into the face of the panels. These panels are extremely heavy, for example a 4 x 8 curtain-wall panel cast from reinforced concrete weighs from 1400 - 1600 lbs., and require heavy construction equipment to install. In addition, these panels provide very poor insulating properties and by themselves are a poor vapor barrier. This necessitates further construction to insulate and seal the stacked-up curtain-wall of precast concrete modules.

The construction industry has long sought improved building elements that will offer advantages in material and - 3 construction costs. A laminated structural element is described in Muhim patent, U.S. 3,295,278, issued January 3, 1967, as consisting of (i) a preformed plastic foam layer, (ii) one or more covering layers of aqueous binding material hardened to impart the strength required for a structure where the structural element is to be used, and (iii) mechanical means interlocking the foam covering layers into a unitary element. Heat insulation is imparted by the plastic foam layer while the required structural strengths are provided by the covering layer or layers.

In one embodiment a preformed plastic foam layer is sandwiched between two concrete layers which are connected through openings in·the. foam layer by a multiplicity of concrete dowels thereby interlocking the layers mechanically.

In another embodiment, a covering layer of a hardened cement having a reinforcement of wood fibers therein is mechanically interlocked by a multiplicity of micro-dowels formed by the binder in surface crevices of the preformed plastic foam layer. The so-called wood-fibers providing the microdowels have a length of 35-50 cm (approximately 14—20 inches).

Another proposal for a laminated insulating panel is set forth in British Patent Specification No. 1,030,333 and involves a preformed insulating layer which is surfaced on one or both sides with at least two layers of cement between which is embedded a glass fiber fabric web. The insulating or core layer, which can carry a static load, is made from a mixture of Portland Cement, an aqueous plastic dispersion, sand and a lesser amount of waste foam formed when foamed plastic parts are sawed. The covering layers are made of similar mixture without sand using greater amounts of waste foam. - 4 A real problem encountered in making laminated panels using preformed plastic foam cores (e.g. polystyrene foam) is the lack of adhesive bond between the core and the covering layer. Muhim attempts to cope with this by providing a mechanical interlock using dowels or micro-dowels to form a unitary element. He also contemplates an extra bonding film to improve adhesion. In the British patent, the covering layers contain a binder which will provide a bond with the insulating core. The use of like materials in both the core and the covering layers makes this possible.

According to one aspect of the present invention we provide a process for making a monolithic-like, composite building module having a fibre-reinforced,continuous and integral cement shell encasing a rigid foam core which comprises: (a) successively applying fibres and wet cement to the bottom of a mould having a bottom and side walls; (b) vibrating to form a layer of wet cement and fibres in the bottom of the mould; (c) placing a rigid foam core member on said layer of wet cement and fibres,said core member having a peripheral shape smaller than the mould interior leaving a free space between the core member and the mould side walls, said core member having a thickness less than the height of the mould side walls; (d) successively applying fibres and wet cement to the top of the core member and the free space between the member and the mould side walls and vibrating to encase said core with a wet cement shell, which shell is continuous, integral around the core and fibre reinforced; and 43358 - 5 (e) curing the wet cement shell and removing the thus formed module from the mould.

According to another aspect of the invention we provide a composite, monolithic-like, insulated building module having a fibre-reinfored shell encasing a rigid foam core, said shell being formed around the core in situ by successively applying fibres and wet cement to the bottom of a mould while vibrating to form a layer of wet cement and fibres in the bottom of the mould, placing the rigid foam core on said layer of wet cement and fibres, wherein said core member has a peripheral shape smaller than the mould interior leaving a free space between the core member and the mould side walls, said core member having a thickness less than the height of the mould side walls and successively applying fibres and wet cement to the top of the core member and the free space between the member and the mould side walls while vibrating thereby encasing said core with a layer of wet cement and fibres.

The monolithic-like composite building module of the invention comprises a core of rigid foam, preferably a rigid urethane polymer foam core completely encased in an enclosed shell made of a fiber reinforced cement, said shell containing from about 1 to 40% by volume of fibers, preferably 2 to 15% by volume glass fibers, having a length of foam 1/8 to 1 inch, preferably from 3/8 to 1 inch, and being substantially uniformly distributed in a random fashion throughout substantially the entire volume of said shell.

The exterior of the shell can be provided with any desired surface finish including aggregates such as stone or marble chips embedded in one or more surfaces thereof and - 6 the module can be used in the same manner as precast concrete modules, without, however the need for heavy construction equipment and further steps to impart insulating and vapor barrier properties thereto.

The present invention will be more fully understood from the following description taken in conjunction with the accompanying drawing wherein; Figure 1 is a cross-sectional view of a typical composite building module of the present invention; Figure 2 is a croSs-sectional view partly in perspective and partly broken away of a composite building module of the invention shown in the form of a highway barrier with a weighted base; and Figure 3 is a perspective view partly broken away of a partly assembled building illustrating various ways in which the composite module of the invention can be utilized in the construction of a building„ Preferred hardenable mixtures for the invention are mixtures of cement, inert particulate filler and glass fibers containing 5-50% or more by volume glass fibers. Mixtures of cement and fibers with lengths of from 1/8 to inch, or longer, can be used in the invention. Suitable fibers, in addition to glass fibers, include organic and inorganic synthetic fibers such as Dacron, Nylon, graphite and the like. Suitable inert particulate fillers include sand, pumice, stone dust, and the like. They can be used in amounts of from 10 to 30% by volume.

The cement/fiber mixtures can contain conventional additives such as lime and sterates. for water resistance and latex for added strength. 43358 Suitable rigid foams include inorganic and organic foams. Preferred foams are polyurethane foams. The desired density of rigid urethane foams to some extent depends on the nature of the urethane composition employed but generally ranges between 1.5 lbs. per cu. ft. to 10 lbs. per cu. ft., more commonly from 2 to 5 lbs per cu. ft. Because of the lightweight closed cell structure of rigid urethane foams, they also have good structural strength. Other suitable rigid foams include polyester foams, phenolic resin foams, isocyanurate foams and the like.

The present invention combines a hardenable mixture of cement and fibres with rigid foams and provides a surprisingly strong and self-supporting building module which is light in weight and has outstanding insulating and vapour barrier properties.

The invention will now be described with reference to the drawing and the preferred embodiment of a rigid urethane foam polymer core and a cement/glass fibre shell.

Figure 1 of the drawing shows a typical building module in cross-section and the component parts are shown in exaggerated proportions for ease in understanding. Thus, the building module of the invention has a rigid urethane polymer foam core 14 encased or encapsulated in a shell 12 made cf a hardened mixture of cement and glass fibers. The finished, monolithic-like module is indicated generally by the reference numeral 10. Figure 2 shows a particular application wherein the building module is in the form of a highway barrier in which base 16 includes a concrete forming aggregate.

An important feature of the present invention is the encapsulation of the rigid foam core 14 by the outer shell 12 and the formation of an intimate adhesive bond 11 between - 8 the core 14 and the shell 12 preferably over the entire surface area of the core 14.

Depending on the intended use for the building module of the invention, the shell 12 can having a thickness ranging from l/8th in. to 1 in. or more. The thickness can be greater or less than this range again, depending upon the ultimate use intended for the building module. For curtainwall panels, the shell 12 preferably has a thickness of from 1/4 in. to 3/8 in.

Likewise, the rigid foam core 14 can range in thickness from 1 in. to 10 in. or more and this can be greater or less depending on the structure involved and the intended use. The building modules themselves can be made in almost any size ranging from small modular units up to relatively large curtain IS wall units or roof deck members.

Figure 3 shows just a few of the many ways in which the building module of the invention can be employed. Because building modules of the invention are like monolithic modules in outward appearance and use, yet self-insulating, the modules of the invention can be used in the same fashion using the same construction and installation techniques as monolithic concrete modules. Thus, the composite module of the invention 10 can be used as a wall panel or roof deck member as shown in Figure 3. The wall panels can be provided with window openings as in panels 18 and 22 or door openings as per panel 20. The modules of the invention can also be used as interior partition wall panels 24 as well as other numerous uses. Because of the light weight of the module of the invention, great savings can be realized in the load bearing structure of buildings. Thus, for example, in a multi-storey, curtain-wall building, considerably less structural steel will be needed 43358 - 9 to support the exterior panels as compared to the structural steel required to support precast concrete panels.

The facing surfaces of the composite panel 10 can be provided with any finish, texture or design which can be imparted via the finish or design of the mould surfaces or by imbedding or adhering aggregate such as gravel, broken stone, marble chips and the like to one or more surfaces Of the shell 12. It is also possible to incorporate aggregate such as sand, gravel, broken stone and marble chips into the mixture of cement and glass fibers before forming the shell 12 for increased strength and also to attain desired surface textures or finishes.

It is preferred to apply a layer of a wet mixture of cement and 1 to 40% by volume glass fibers to the bottom of the mold, laying in a foam core which is smaller than the mold interior, applying the same wet mixture down into the side spaces and the top and then vibrating the entire assembly. Glass fibers can be put into the mold first (using only wet cement) before applying the bottom layer, then down the sides and onto the top of the core before applying the remaining cement. Vibration causes the lighter fibers to rise in the wet cement and thereby become evenly distributed throughout the shell.

In the embodiment of Figure 1, the juncture between the open shell 12 and the cover or top 12' can be formed at roughly 45° angles as shown, or any combination of right-angles can be employed, including a set-in or overlapping configuration. Where the two members 12 and 12' come together as shown in Figure 1, the mating edges can be formed to leave a slight gap so that foaming polymer can enter therein during the foaming operation. - 10 Many modifications can be made in the composite building modules of the invention without departing from the spirit and scope hereof. For example, the rigid foam core 14 can be reinforced utilizing woven or non-woven screen and mesh layers made of synthetic fibers or metals and prestressing techniques can be employed if desired. As mentioned previously, one or more exterior surfaces of the shell 12 can be provided with any desired finish, texture or design or can be embedded with inorganic aggregates such as gravel, broken stone, marble chips and the like. As for surface design and texture, the exterior of the shell 12 will conform to the finish of the mold surface to achieve desired effects, for example, a wood grain appearance and the like. The shell 12 can also be formed with molded-in mounting or building clips and/or grooves.

As mentioned previously, the composite building module of the invention can be used and installed in the same manner as conventional building modules such as curtain-wall panels but with a great reduction in weight (and simplified installation procedures). Because of the greatly improved insulating and water vapor barrier properties of the modules of the invention, no further steps have to be taken to ensure these properties as is the case with conventional building modules. in roof deck installations or curtain-wall installations, a room temperature curing elastomer such as a silicone elastomer can be used for edge to edge bonding between adjacent modules and the entire installation can be provided with an overcoating of a suitable elastomer. This provides for a shock resistant installation which can also compensate for later movement of a structure, for example, as a building settles after construction.

Because the composite building modules of the invention - 11 are extremely light as compared to conventional monolithic cast concrete modules, fewer structural members are necessary for supporting, for example, a curtain-wall made of panels of the present invention and a roof deck made of panels of the present invention. For example, a 4' x 8' precast concrete module weighs from about 1400-1600 lbs., whereas a comparable composite module made according to the invention weighs only about 100 - 150 lbs. depending on the thickness of the shell 12. Thus, great savings can be realized in not only installation procedures but also in the strength requirements for the supporting superstructure.

In addition to the uses illustrated in Figures 2 and 3 of the drawing, the composite module in the invention can be formed into insulated pipes and conduits, railroad ties, modular walls and even load bearing modular panels whioh can incorporate conduits for utilities, window frames, door frames and the like. It should also be noted that the composite building panel of the .invention is buoyant because of the rigid foam core 14 which property can be utilized to advantage in the construction of floating docks and wharfs as well as offshore drilling platforms.

It is known that a l/8th in. or 1/4 in. coating of a hardened mixture of cement and glass fibers gives acceptable fire ratings to the underlying coated base. Thus, in a preferred embodiment of the invention, rigid urethane polymer foams are provided with acceptable fire ratings by forming a laminate of a layer of rigid urethane polymer foam with an outer covering layer made of a hardened mixture of cement and glass fibers.

Foamable urethane compositions forming rigid urethane polymer foams are commercially available in a wide range of chemical and physical properties. Such compositions generally 43358 - 12 contain an isocyanate component containing reactive isocyanate groups, a polyol component containing one or more polyols, catalytic agents and preferably a flame or fire resistant agent such as trichloromonofluoro methane. Typical properties of rigid urethane polymer foams available commercially are set forth in the table below.

TYPICAL RIGID URETHANE FOAM PROPERTIES Density Ib./cu.ft. Astm D 1622 Compressive Strength psi Astm D 1621 Compressive Modulus psi Astm D 1621 Shear Strength psi Shear Modulus psi 1.5—2.0 20—60 400—2000 20—50 250—550 2.1—30 35—95 800—3500 30—70 350—800 3.1—45 50—185 1500—6000 45—125 500—1300 4.6—70 100—350 3B00—12,000 75—180 850—2000 7.1—10.0 200—600 5000—20,000 125—275 1300—3000 Suitable formable urethane compositions are : sold by Witco Chemical Corporation, New Castle, Delaware, and by Owens-Corning Fiberglass Corp., Toledo, Ohio.

Composite building modules and processes for making them are described and claimed in Patent Specification Wo. b'l-QSq which was divided from the present application.

Claims (23)

1. C1A1MS:1. A process for making a monolithic-like, composite building module having a fibre-reinforced, continuous and integral cement shell encasing a rigid foam core which comprises; (a) successively applying fibres and wet cement to the bottom of a mould having a bottom and side walls? (b) vibrating to form a layer of wet cement and fibres in the bottom of the mould; (c) placing a rigid foam core member on said layer of wet cement and fibres, said core member having a peripheral shape smaller than the mould interior leaving a free space between the core member and the mould side walls, said core member having a thickness less than the height of the mould side walls; (d) successively applying fibres and wet cement to the top of the core member and the free space between the member and the mould side walls and vibrating to encase said core with a wet cement shell, which shell is continuous, integral around the core and fibre reinforced; and (e) curing the wet cement shell and removing the thus formed module from the mould.

2. A process according to Claim 1 in which the fibres and wet cement are applied successively to the bottom of the mould whilst vibrating to form said layer in the bottom of the mould.

3. A process according to Claim 1 or 2 in which the fibres and wet cement are applied successively to the top of the core member whilst vibrating. - 14

4. A process according to any of Claims 1 to 3 wherein the cement used in steps (a) and (d) contains an inert, particulate filler such as sand.

5. A process according to any of Claims 1 to 4 wherein the reinforced cement shell encasing said rigid foam core has a thickness of from-one-eighth to one inch.

5. A process according to any of Claims 1 to 4 wherein said rigid foam core member has a thickness of from one to ten or more inches.

7. A process according to any of Claims 1 to 6 wherein said rigid foam core member is made of rigid urethane polymer foam.

8. A process according to any of Claims 1 to 7 wherein said fibres used in steps (a) and (d) are glass fibres.

9. A process for making a composite building module substantially as herein described with reference to the accompanying drawings.

10. A composite, monolithic-like, insulated building module having a fibre-reinforced cement shell encasing a rigid foam core, said shell being formed around the core in situ by successively applying fibres and wet cement to the bottom of a mould while vibrating to form a layer of wet cement and fibres in the bottom of the mould, placing the rigid foam core on said layer of wet cement and fibres, wherein said core member has a peripheral shape smaller than the mould interior leaving a free space between the core member and the mould side walls, said core member having a thickness less than the height of the mould side walls and successively applying fibres and wet cement to the top of the core member and the free space between the member and the mould side walls while 43358 - 15 vibrating thereby encasing said core with a layer of wet cement and fibres.

11. A composite module according to Claim 10 wherein the shell contains from about 5 to 50% by volume of glass 5 fibres substantially uniformly distributed in a random fashion throughout substantially the entire volume of the shell.

12. A composite building module according to Claim 10 or 11 wherein the shell is made from cement containing inert, 10 particulate filler.

13. A composite module according to any of Claims 10 to 12 wherein said shell is from 1/8 to 1 inch thick.

14. A composite module according to any of Claims 10 to 12 wherein said core is from one inch to at least ten inches IS thick.

15. A composite module according to any of claims 10 to 14 wherein the core is an in situ formed, rigid urethane polymer foam.

16. A composite module according to any of Claims 10 20 to 15 wherein said fibres are glass fibres having a length of from 3/8 to 1 inch.

17. A composite module according to any of Claims 10 to 16 in the form of a wall panel.

18. A composite module according to Claim 17 wherein 25 said wall panel is provided with a door or a window opening.

19. A composite module according to any of Claims 10 to 16 in the form of a roof deck.

20. A composite module according to any of Claims 10 to 16 in the form of a highway barrier.

4. 2358 - 16 21. A composite module according to Claim 20 wherein said barrier has a weighted base.

22. A composite module according to any of Claims 10 to 21 wherein aggregate is embedded in one or more outer

5. Surfaces of said shell.

23. A composite building module substantially as herein described with reference to, and as shown in, the accompanying drawings.