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Publication numberUS3292326 A
Publication typeGrant
Publication dateDec 20, 1966
Filing dateMay 28, 1963
Priority dateMay 29, 1962
Also published asDE1409969A1
Publication numberUS 3292326 A, US 3292326A, US-A-3292326, US3292326 A, US3292326A
InventorsWilhelm Holzwarth
Original AssigneeOlaculith Patentverwertungs A
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Heat-resistant structural element and the like
US 3292326 A
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Description  (OCR text may contain errors)

QLHH-bi'i m; m lziaall UM Dec. 20, 1966 w, o zw 3,292,326

T HEAT-RESISTANT STRUCTURAL ELEMENT AND THE LIKE CROSS REERENCE Filed May 28, 1963 United States Patent HEAT-RESISTANT STRUCTURAL ELEMENT AND THE LIKE Wilhelm Holzwarth, Frankfurt am Main, Germany, assignor to Olaculith Patentverwertungs A.G. Filed May 28, 1963, Ser. No. 284,780

Claims priority, application Germany, May 29, 1962,

Claims. (Cl. 52-232) The present invention relates to a heat-resistant structural element or the like and, more particularly, the present invention is concerned with a structural or building element having fire-resistant and heat-insulating properties and, according to a preferred embodiment of the present invention, also having radiation-blocking propertim, which element may be in the shape of a plate, a box, a shell for covering another body or building element and the like. It is frequently desirable and sometimes required by building ordinances and the like to protect building elements against fire and heat. For instance, the steel skeleton of buildings usually must be covered with fire-resistant material. More recently it has also been required in many cases that structures of reinforced concrete, particularly with prestressed reinforcements, as well as other temperature sensitive structures are shielded or covered with fire-resistant material.

conventionally, protection against fire was accomplished by applying to an intermediate wall or, for instance, to a false ceiling of wire mesh a mortar or plaster layer which layer was required to have a thickness of at least 3 cm. and had to be formed of highly insulating fireresistant mortar or plaster. Considerable labor is involved in applying such plaster layer of the required thickness and, furthermore, since the plaster layer has to be applied in wet condition, temporarily the supporting structure has to carry a weight which is considerably greater than that of the dried plaster layer. In order to be able to carry the wet weight of the plaster layer, the dimensions of the supporting structure frequently have to be increased considerably beyond the dimensions which would be required for carrying only the dry plaster layer. Furthermore, considerable quantities of moisture are introduced in the form of wet plaster or mortar and the drying of the protective layer requires time and possibly heating or ventilating arrangements, all of which increases the costs of providing the fire and heat protection.

It has been tried to overcome the above discussed difi'iculties and disadvantages by forming a protective structure of prefabricated plates. However, the plates suggested for this purpose up to now do not seem to -fulfill all requirements with respect to fire resistance and heat insulation. Upon prolonged testing, most of these prefabricated plates could not withstand the required high temperatures, or, in fire tests, the plates were damaged by the 'water used for extinguishing the fire. It was also not possible in these cases to sufficiently prevent or reduce the passage of heat through the joints between adjacent plates. Thus, there are, for instance, no prefabricated plates available which, with respect to fire resistance will comply with the German standards DIN 4102 and which, in accordance therewith, could be labeled as fire-resistant structural or building elements.

It is therefore an object of the present invention to overcome the above-discussed difficulties and disadvantages in the protection of building elements and the like against fire and heat.

It is a further object of the present invention to provide a shaped, prefabricated building element and a structure consisting of a plurality of such building elements joined to each other, which structure, for instance, may be in the shape of plates, boxes, or shells of any configuration 3,292,326 Patented Dec. 20, 1966 suitable for protecting the structure covered thereby, which protective building element or structure will possess high fire-resistant and heat-insulating properties and can be produced and assembled in a simple and mechanical manner.

It is yet another object of the present invention to provide such protective fire and heat-resistant element and structure which, in addition thereto, will also be capable of absorbing and thereby blocking the passage of radiation.

Other objects and advantages of the present invention will become apparent from a further reading-of the description and of the appended claims.

With the above and other objects in view, the present invention includes a composite structure element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of shaped solid bodies consisting of a mixture of (1) a substance selected from the group consisting of expanded perlite and vermiculite, (2') clay and (3) a substance selected from the group consisting of cement and gypsum, the shaped solid bodies being arranged adjacent to each other with adjacent edge faces of adjacent bodies spaced from each other but a short distance defining a narrow open space therebetween, and a solid binder consisting essentially of an intimate mixture of perlite, glass powder, water glass and clay substantially filing the narrow open space thereby firmly adhering the shaped solid bodies to each other.

The term cement as used in the following specification and claims is intended to include also gypsum.

According to a preferred embodiment of the present invention, the same comprises in a composite structural element having fire-resistant and heat-insulating properties, a plurality of plates consisting of about six parts by volume of perlite, about two parts by volume of plaster of Paris and about one part by volume of bentonite, the plates having reinforcing members of expanded metal incorporated therein and the plates being arranged adjacent to each other in edge-to-ed-ge relationship, adjacent edges of adjacent plates having along the length thereof spaced projections and recesses, the projections of one of the adjacent edges registering with the recesses of the other of the adjacent edges and being located within and spaced from the .same so as to define a narrow open space between the adjacent edges; a solid binder consisting essentially of about two parts by volume of water glass, about two and one half parts by volume of glass powder, about two and one half parts by volume of perlite, and about one half part by volume of benton-ite filling the narrow open space thereby forming a composite plate having opposite faces, and a layer consisting of about fifty parts by volume of lead powder, about thirty parts by volume of quartz sand, about ten parts by volume of cement and about ten parts by volume of bentonite, the layer having radiation-blocking properties, substantially coverin g one of the opposite faces.

Thus, according to the present invention, it is possible by assembling prefabricated bodies of the desired shape to provide fire resistant and heat insulating coverings or casings which will have the desired fire resistance and heat insulating properties throughout, including the joints between the individual plates or the like and also including the portions thereof at which the protective structure is supported or suspended.

According to the present invention an insulating material of the above described composition is combined with certain structural features of the edges of the insulating bodies, plates or the like, which are located adjacent to and facing each other; and the joints between adjacent insulating bodies are filled with a binder material of the above described composition.

Preferably, the insulating plates or the like are formed of an intimate mixture of about six parts by volume of perlite, about one part by volume cement and one part by volume clay. Throughout the present specification and claims wherever proportions are given in parts by volume, it is to be understood that such proportions may deviate upwardly and downwardly by up to about Thus, for instance, six parts by volume of perlite are meant to denote between 5.4 and 6.6 parts by volume thereof.

Perlite is a well known inorganic incombustible material containing closed micropores and is produced of volcanic mineral in an expansion process requiring heating of the mineral to more than 1000 C. By this expansion process, the volume of the mineral material is increased to between about and times its orginal volume. Perlite is resistant to moisture, non-hygroscopic and possesses a relatively high pressure resistance. The heat conductivity of perlite (lamba) equals between 0.034 and 0.040 kcaL/mh. C. Preferably, a commercially available perlite having particle sizes of up to 4 mm. and a specific gravity of between 50 and 70 kg./m. is used. The cement preferably will be of a quickly binding type and the preferred clay is natural bentonite corresponding substantially to the formula:

It is also possible to replace the cement of the plate forming mixture with gypsum or preferably with plaster of Paris. In this case, the preferred composition of the mixture will be six parts by volume of perlite, two parts by volume of gypsum and one part by volume of clay.

Insulating bodies according to the present invention which will be exposed to atmospheric conditions or placed in moist locations are preferably made of a cement-containing mixture.

In all of the above described mixtures, perlite may be replaced with an equal proportion of vermiculite.

Preferably, the adjacent edges of adjacent insulating plates or the like according to the present invention will dove-tail or will be formed with registering projections and recesses whereby a depth of the recess of between about 2 and 2.5 cm. will suffice. However, the adjacent edges may also be formed with other types of overlapping or intermeshing faces.

The joints formed between adjacent edges are then filled with a binder material which originally contains an organic binder, perlite, glass powder and clay, the latter preferably in the form of bentonite.

Preferably, the binder material will be of the following composition: two parts by volume of a 50% nonre-emulsifiable dispersion of polyvinylpropionate, for instance of the type known as Propiofan 5D, 6D made by BASF, 2 parts by volume of water glass, 2.5 parts by volume of perlite, 2.5 parts glass powder and 0.5 part bentonite.

The 50% polyvinylpropionate dispersion commercially available from the Badische Anilin- & Soda-Fabrik AG under the trade name Propiofan can be diluted with water to any desired degree but will give upon drying a water insoluble film which cannot be re-emulsified. The size of the suspended particles is between 0.3 and 2 microns.

The organic binder material of the above mixture which initially provides the adhesive power will be destroyed upon exposure to sufiiciently high temperatures and the remaining inorganic constituents of the mixtures will then form a firm fire resistant and heat insulating bonding material which may safely be exposed to temperatures of up to and even in excess of 1000 C.

To increase the mechanical strength of the prefabricated insulating plates or bodies, particularly when the same are of relatively large dimensions, it is preferred to reinforce the same by embedding in the plate forming material or the like, during molding of the same, a reinforcing structure consisting, for instance, of a mesh of structural steel. Preferably expanded metal formed with flat ribs is used for this purpose and it has been found that expanded metal which has a maximum cross sectional dimension of about 5 mm. is particularly suitable.

For most purposes a plate thickness of between about 30 and 38 mm. will sufiice, however, it is of course within the scope of the present invention to provide plates or other shaped fire resistant and heat insulating bodies of greater or also of smaller cross sectional dimensions.

According to a preferred embodiment of the resent invention, the heat insulating and fire resistant structure will also absorb and thus block radiation such as radioactive rays. This is achieved by applying to one face of the insulating body a lead-containing layer, having a thickness of for instance 20 mm. Such radiation blocking layer may be formed of a mixture of 50 parts by volume lead powder having a particle size of up to 1 mm., 30 parts by volume quartz sand, 10 parts by volume cement and 10 parts by volume clay, preferably bentonite. Here again it should be understood that the indications of volumetric proportions are meant to include a tolerance of 10% in either direction.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention, itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which the figure is a fragmentary elevational view, partially in cross section of a ceiling structure protected against heat, fire and radiation in accordance with the present invention.

As shown in the drawing, the ceiling structure comprises I-bearns 1 supporting a steel reinforced concrete plate 2. The protective structure according to the present invention consists of a false ceiling which is suspended from I-beams 1. Elongated bars 4 of T-shaped cross section are suspended by suitable hook-shaped elements and wires from elongated bars 3 of suitable cross section which rest on the lower flanges of the beams 1, portions of the bars 4 also being connected to the lower flanges of the beams 1. The lower portions of the bars 4 are perforated and have fastened thereto, by means of countersunk screws, the insulating plates which have a thickness of approximately 30 mm. and which are reinforced with expanded, ribbed steel 9. The insulating plates 5 are provided with mating projections 6 which complement and overlap each other at the side edges of the plates 5. The gaps between the overlapping portions 6 are filled and sealed with the binder material 7 described further above. The space between the lower side of the beams 1 and the upper side of the insulating plates 5 may be approximately 65 mm.

If protection against radiation is desired, a layer of radiation blocking material 8 may be applied to the lower face of the false ceiling formed by plates 5.

The above described ceiling structure was installed in a test building, the false ceiling extending horizontally and so that the distance between parallel I-beams 1 amounted to 4 meters. A fire test was then carried out in accordance with German standards DIN 4102. Within 10 minutes, the temperature within the test building reached 650 C., after 30 minutes 880 C., after 60 minutes 1000 C. and after minutes about 1025 C. Thereafter, the fire was extinguished within three minutes by applying a stream of water at a gauge pressure of two atmospheres from a distance of 3 meters.

It was found that 90 minutes after start of the test, at which time the temperature within the test building had reached 1012 C., the average temperature at the reinforced concrete plates 2 amounted to only 38 C. The temperature at the lower flange of I-beams 1 did not rise above 88 C. Surprisingly, it was also found that the portion of the upper face of the false ceiling formed of plates 5 did not exceed 57 C. even at the binderfilled joints thereof. During the subsequent extinguishing of the fire by applying water under pressure as described above, the false ceiling resisted the stream of water without breaking.

It was thus found that the protective ceiling structure according to the present invention could resist for one and one-half hours exposure to fire and subsequent contact with water under pressure used for extinguishing the fire and that during the entire test the structure of the false ceiling remained essentially unaffected.

The mechanical strength of the entire ceiling structure including its load carrying capacity was not diminished and the fire could not penetrate through the false ceiling. Thus, the structure according to the present invention and as illustrated herein complied with the requirements of the German standards applicable for fire resistant structural elements.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of protective structural elements differing from the types described above.

While the invention has been illustrated and described as embodied in a fire and heat resistant false ceiling, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in anyway from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A composite structural element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of shaped solid bodies consisting of a mixture of (1) a substance selected from the group consisting of expanded perlite and vermiculite, (2) clay and (3) cement, said shaped solid bodies being arranged adjacent to each other with adjacent edge faces of adjacent bodies spaced from each other but a short distance defining a narrow open space therebetween; and a solid binder consisting essentially of an intimate mixture of perlite, glass powder, water glass and clay substantially filling said narrow open space thereby firmly adhering said shaped solid bodies to each other.

2. In a building structure, a first Wall; a second wall adjacent said first wall, said second wall comprising a plurality of plates consisting of a mixture of (1) a substance selected from the group consisting of expanded perlite and vermiculite, (2) bentonite and (3) cement, said plates being arranged adjacent to each other with adjacent edge faces of adjacent plates spaced from each other but a short distance defining a narrow open space therebetween, and a solid binder consisting of an intimate mixture of an organic binder material, perlite, glass pow der, water glass and clay substantially filling said narrow open spaces thereby firmly adhering said plates to each other; and attaching means for attaching said second wall to said first wall, whereby said first Wall will be protected against fire and heat by the interposition of said second wall between said first Wall and a source of fire and heat.

3. A composite structural element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of plates consisting of a mixture of (1) a substance selected from the group consisting of expanded perlite and vermiculite, (2) bentonite and (3) cement, said plates being arranged adjacent to each other in edge-to-edge relationship, adjacent edges of adjacent plates having along the length thereof spaced projections and recesses, the projections of one of said adjacent edges registering with the recesses of the other of said adjacent edges and being located within and spaced from the same so as to define a narrow open space between said adjacent edges; and a solid binder consisting essentially of an intimate mixture of an organic binder material, perlite, glass powder, water glass and clay substantially filling said narrow open space thereby firmly adhering said plates to each other.

4. A composite structural element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of shaped solid bodies consisting of a mixture of (1) about six parts by volume of a substance selected from the group consisting of expanded perlite and vermiculite, (2) about one part by volume of clay and 3) about one part by volume of cement, said shaped solid bodies being arranged adjacent to each other with adjacent edge faces of adjacent bodies spaced from each other but a short distance defining a narrow open space therebetween; and a solid binder consisting essentially of an intimate mixture of perlite, glass powder, water glass and clay substantially filling said narrow open space thereby firmly adhering said shaped solid bodies to each other. 1

5. A composite structural element having fire-resistan and heat-insulating properties, comprosing, in combination, a plurality of shaped solid bodies consisting of a mixture of about six parts by volume of perlite about two parts by volume of plaster of Paris and about one part by volume of bentonite, said shaped solid bodies being arranged adjacent to each other with adjacent edge faces of adjacent bodies spaced from each other but a short distance defining a narrow open space therebetween; and a solid binder consisting essentially of an intimate mixture of perlite, glass powder, water glass and clay substantially filling said narrow open space thereby firmly adhering said shaped solid bodies to each other.

6. A composite structural element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of plates consisting of a mixture of (l) a substance selected from the group consisting of expanded perlite and vermiculite, (2) clay and (3) cement, said plates having reinforcing members of expanded metal incorporated therein and said plates being arranged adjacent to each other with adjacent edge faces of adjacent bodies spaced from each other but a short distance defining a narrow open space therebetween; and a solid binder consisting essentially of an intimate mixture of perlite, glass powder, water glass and clay substantially filling said narrow open space thereby firmly adhering said plates to each other.

7. A composite structural element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of shaped solid bodies consisting of a mixture of (1) a substance selected from the group consisting of expanded perlite and vermiculite, (2) clay and (3) cement, said shaped solid bodies being arranged adjacent to each other with adjacent edge faces of adjacent 'bodies spaced from each other but a short distance defining a narrow open space therebetween; and a solid binder consisting of about two parts by volume of a 50% dispersion of polyvinyl propionate, about two parts by volume of water glass, about two and one half parts by volume of glass powder, about two and one half parts by volume of perlite and about one half part by volume of bentonite filling said narrow open space thereby firmly adhering said shaped solid bodies to each other.

8. A composite structural element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of plates consisting of a mixture of 1) a substance selected from the group consisting of expanded perlite and vermiculite, (2) clay and (3) cement, said plates being arranged adjacent to each other with adjacent edge faces of adjacent plates spaced from each other but a short distance defining a narrow open space therebetween; a solid binder consisting essentially of an intimate mixture of perlite, glass powder, water glass and clay substantially filling said narrow open space thereby and heat-insulating properties, comprising, in combination, a plurality of plates consisting of a mixture of (1) a substance selected from the group consisting of expanded perlite and vermiculite, (2) clay and (3) cement, said plates being arranged adjacent to each other with adjacent edge faces of adjacent plates spaced from each other but a short distance defining a narrow open space therebetween; a solid binder consisting essentially of an intimate mixture of perlite, glass powder, water glass and clay substantially filling said narrow open space thereby forming a composite plate having opposite faces; and a layer consisting of about fifty parts by volume of lead powder, about thirty parts by volume of qpgrtz 82nd,.

about ten parts by volume of cement and about ten parts by volume of bentonite, said layer having radiation-blocking properties, substantially covering one of said opposite faces.

10. A composite structural element having fire-resistant and heat-insulating properties, comprising, in combination, a plurality of plates consisting of about six parts by volume of perlite, about two parts by volume of plaster 39 of Paris and about one part by volume of bentonite, said plates having reinforcing members of expanded metal incorporated therein and said plates being arranged adjacent to each other in edge-to-edge relationship, adjacent edges of adjacent plates having along the length thereof spaced projections and recesses, the projections of one of said adjacent edges registering with the recesses of the other of said adjacent edges and being located within and spaced from the same so as to define a narrow open space between said adjacent edges; a solid binder consisting essentially of about two parts by volume of water glass, about two and one half parts by volume of glass powder, about two and one half parts by volume of perlite, and about one half part by volume of bentonite filling said narrow open space thereby forming a composite plate having opposite faces; and a layer consisting of about fifty parts by volume of lead powder, about thirty parts by volume of quartz sand, about ten parts by volume of cement and about ten parts by volume of bentonite, said layer having radiation-blocking properties, substantially covering one of said opposite faces.

References Cited by the Examiner UNITED STATES PATENTS 2,037,294 4/1936 Williamson 52-612 2,213,603 9/1940 Young 52-612 2,466,106 4/1949 Hoge 52483 2,703,289 3/1955 Wilson 52-612 3,015,626 1/1962 Kingsbury 252- 62 3,095,347 6/1963 Becker 106122 X FRANK L. ABBOTT, Primary Examiner.

I. E. MURTAGH, Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2037294 *Jan 11, 1933Apr 14, 1936Roger W WilliamsonLaminated material
US2213603 *Oct 14, 1938Sep 3, 1940Robertson Co H HFireproof building structure
US2466106 *Mar 2, 1944Apr 5, 1949Clyde Hoge EdwardPreformed slab structures
US2703289 *Oct 23, 1950Mar 1, 1955Willson Corwin DCement bound lightweight aggregate masses
US3015626 *Sep 29, 1959Jan 2, 1962Kingsbury John CInsulating composition
US3095347 *Sep 11, 1958Jun 25, 1963Johns Manville Perlite CorpInsulating material and the like
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3422587 *Jan 5, 1968Jan 21, 1969Murray Malcolm GPlasterboard with a remoistenable plaster facing
US4829734 *Oct 31, 1986May 16, 1989Eltech Systems CorporationCeramic fiber insulation module and method of assembly
US5176876 *Oct 10, 1990Jan 5, 1993Simko & Sons Industrial Refractories Inc.Insulating ceramic fiber batting module, anchoring system, ladle cover assembly and method of assembly
US5234660 *Jun 25, 1992Aug 10, 1993Simko & Sons Industrial Refractories, Inc.Insulating ceramic fiber batting module, anchoring system, ladle cover assembly and method of assembly
WO2008091369A2 *Jul 11, 2007Jul 31, 2008Battelle Energy Alliance LlcArmor structures
Classifications
U.S. Classification52/232, 106/18.11, 106/602, 52/515, 52/436, 52/415, 106/611, 106/632, 52/506.3, 52/612
International ClassificationC04B28/02, E04B9/04, E04B9/22, C04B28/26, E04B1/94, E04C2/04
Cooperative ClassificationE04B9/04, E04B1/94, C04B2103/0091, C04B28/26, C04B2111/00612, E04B9/22, C04B2111/00862, C04B28/02, E04C2/049
European ClassificationE04B1/94, E04B9/04, E04B9/22, C04B28/26, E04C2/04F, C04B28/02