BACKGROUND
The present invention relates generally to the construction of building frames for residential and commercial structures, and more specifically to such frames employing steel beams (horizontal) and columns (axial) that by building code are required to be encased with fire-resistant material.
According to the International Building Code (IBC) Section 704.2, relating to “Column Protection,” in applicable situations where columns are required to have protection to achieve a designated fire-resistance rating, the entire column, typically made of steel, is typically encased on all sides and for the full column height with fire-resistant material. The encasement needs to include connections to other structural members.
In practice, the encasement procedure is time consuming, costly and in many situations is difficult to fabricate, particularly relating to the connection points between structural members. The difficulties are particularly applicable in modular construction, of the type disclosed in commonly-assigned U.S. Pat. No. 10,066,390 which is incorporated by reference.
Thus, there is a need for a cost-effective alternative to the prescribed encasement procedure that is comparable in strength to the conventional building frame structure.
SUMMARY
The above-listed need is met or exceeded by the present prefabricated load-bearing structural members usable both as axial columns and horizontal beams in creating building frames. Use of the present members achieves the goals of providing structurally strong building support, but avoids the requirement of conventional building codes for encasing traditional structural steel members with fire-resistant cladding in the form of panels with gypsum wallboard or cement based panels.
The inventors have capitalized on the considerable strength of conventional fiber-reinforced cementitious structural panels of the type disclosed in commonly-assigned U.S. Pat. Nos. 6,986,812; 7,445,738; 7,670,520; 7,789,645; and 8,030,377, all of which are incorporated herein by reference, and sold by United States Gypsum Company under the mark STRUCTO-CRETE® panels. Such panels are known to have both compressive strength and axial strength that approaches or exceeds that of structural grade steel, especially when multiple layers are laminated together. In the present load-bearing structural members, multiple layers of structural cement panels (and optionally interspersed wallboard panels in certain applications) are secured together using chemical adhesives and/or fasteners to create laminated structural members usable as columns or beams in the fabrication of building frames. Individual layers of the members are contemplated as being the standard 0.5 inch or 0.75 inch thickness of known structural cement panels. The number of thicknesses of such standard panels may vary from at least two to six, eight or more, depending on the application.
When used as a horizontal beam, it is envisioned that each member of the laminate is positioned so that a width of the laminate is facing vertically. Thus, from a top, bottom or end view, one can easily see the thickness of each laminate layer, but from a side view, one sees only the top or bottom width surface of a single member of the laminate. Depending upon the number of layers, members of the laminate may be rotated, the width increased or decreased, and both the thickness and width of the laminate layers may be visible. When used as a vertical column, the orientation of the laminate is contemplated as varying with the application.
A standard length of such panels is 8 feet, which is also envisioned as one available length of the members. However, the present member includes an embodiment where multiple layers are assembled in varying lengths, in a staggered “bricklayer” pattern when viewed from above or below on a beam, to create a structural member of lengths greater than 8 feet. Given that the length of the laminate layers may vary, a void or gap in the beam or column may be visible.
More specifically, a structural member for building fabrication is provided, including, at least two layers of structural cement panels fastened together. In an embodiment, the attached layers have a common, aligned length and a common, aligned width.
In one embodiment, at least four layers of structural cement panels are fastened together to form the structural member. In an embodiment, the layers are fastened together using chemical adhesive. In an embodiment, the layers are fastened together with threaded fasteners. In one embodiment, a layer or panel of steel is located between adjacent layers of the at least two layers of structural cement panel and fastened to the adjacent layers.
In an embodiment, members of the at least two layers are provided in varying lengths secured together in lengthwise staggered fashion to provide a member with a length greater than eight feet long. In an embodiment members of the at least two layers have extensions for securing to adjacent members in a tongue and groove arrangement. In an embodiment, the member is provided with gaps created by using panels of varying lengths.
In another embodiment, a building frame is provided, including: a plurality of columns each having a lower end and an upper end, a plurality of beams each secured to at least one of the columns. Each of the columns and beams made of a plurality of layers of structural cement panels fastened together.
In an embodiment of the building frame, the beams are configured so that each said panel is oriented so that a width of the panel projects vertically. In an embodiment of the building frame, at least one of the columns, and at least one of the beams are configured by at least four layers of structural cement panels fastened together.
In a further embodiment of the building frame, layers of the columns and beams are fastened together using chemical adhesive, and/or threaded fasteners.
In another embodiment of the building frame, in at least one of the columns and at least one of the beams, a layer or panel of steel is located between adjacent layers of at least two layers of structural cement panel and fastened to the adjacent layers.
In an embodiment of the building frame, members of the at least two layers are provided in varying lengths secured together in lengthwise staggered fashion to provide a member with a length greater than eight feet long.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary front elevation of a building frame constructed using the present laminated structural members;
FIG. 2 is an enlarged, fragmentary view of the building frame of FIG. 1;
FIG. 3 is a top exploded view of the present laminated structural member;
FIG. 4 is a top view of an alternate embodiment of the present laminated structural member;
FIG. 5 is a top view of still another alternate embodiment of the present laminated structural member;
FIG. 6 is a fragmentary side perspective view of a building frame intersection of the present structural members used as a vertical column and as a horizontal beam;
FIG. 7 is a fragmentary top view of another embodiment of the present laminated structural member; and
FIG. 8 is a fragmentary top view of still another embodiment of the present laminated structural member.
DETAILED DESCRIPTION
Referring now to FIGS. 1 and 2, a building frame is generally designated 10, and is contemplated as being used to construct or renovate new and existing buildings and structures. A foundation 12, typically made of poured concrete as is known in the field, secures the building frame 10 to the ground or substrate 14. If desired, the foundation 12 includes a cellar or basement (not shown). A lowest horizontal beam 16 also referred to as a floor beam, rim joist or ledger, is secured, as by fasteners, hangers, straps, clips and/or chemical adhesives or the like to an upper surface 18 of the foundation 12. Preferably, the floor beams 16 define a periphery of the building frame 10, here shown as a square, but other shapes are contemplated, depending on the desired profile of the building or structure. If necessary, to fully cover the upper surface 18, the floor beams 16 are placed end-to-end and secured in place, as is common with conventional wooden or steel building frame members.
Secured to the floor beams 16 are several vertical columns 20 spaced apart as specified by structural design and model building codes, such as 16-inch on center spacing.
Also, between the floor beams 16 are a plurality of spaced floor joists 22 (FIG. 2) mounted in spaced parallel orientation to a pair of opposed floor beams. The floor joists 22 are contemplated as preferably having the same construction as the beams 16 and columns 20 discussed below. Subflooring panels 24, made of heavy-duty plywood, structural cement panels or the like, are secured to the floor joists 22 to form a floor.
As seen in FIG. 1, the building frame 10 forms a first floor 26 secured to the foundation 12, a vertically displaced second floor 28 above the first floor, and a further vertically displaced third floor 30 above the second floor. It will be noted that the third floor 30 includes a window 32 formed by short beams referred to as lintels 34. In the present application, lintels 34 are formed similarly to the beams 16. Also, between the vertical columns 20, it is contemplated that the building frame 10 include traditional studs 36 made of steel “C”-channel or wooden dimensional lumber configuration. Also, conventional RC channel 38 is optionally secured to an underside of the second floor 28 for accepting wallboard panels or ceiling tile to form a ceiling (not shown).
Referring now to FIGS. 1-6, an important feature of the present building frame 10 is that at least one and preferably each of the beams 16, and at least one and preferably each of the columns 20 is made of a structural member 40 made up of at least two layers of preferably fiber-reinforced structural cement panels 42 fastened together. In one embodiment, the attached layers are configured to have a common, aligned length and a common, aligned width. While other types of structural cement panels 42 are contemplated, in the preferred embodiment, the panels 42 are fiber-reinforced cementitious structural panels of the type disclosed in commonly-assigned U.S. Pat. Nos. 6,986,812; 7,445,738; 7,670,520; 7,789,645; and 8,030,377, all of which are incorporated herein by reference, and sold by United States Gypsum Company under the mark STRUCTO-CRETE® panels.
As seen in FIG. 3, the member 40 is made up of at least two and preferably four layers 42 of structural cement panel 42, each adjacent layer of panels being secured together by at least one of a layer of chemical adhesive 44 and at least one fastener 46. In some applications, it is contemplated that the members 40 are optionally fabricated using conventional wallboard panels 42′ intermixed with the structural cement panels 42.
The fasteners 46 are preferably threaded fasteners, such as bolts 46a and specialized screws 46b. In the case of the bolts 46a, which pass through throughbores in the member 40, washers 48 and nuts 50 are provided to secure the layers of panels 42 together. Screws 46b are employed in applications where an outside face 52 of the member is needed to be flush for the mounting of other building components. While only samples of the fasteners 46a, 46b are depicted, it will be understood that each member 40 has a plurality of such fasteners in suitably spaced orientation for forming a rigid structure.
Referring now to FIGS. 3 and 6, it should be noted that in the case of the members 40 being used as horizontal beams 16, the member is oriented in the building frame 10 so that a width 54 of the panel projects vertically. In other words, as seen in FIGS. 3 and 4, the panels 42 have side edges 56 that are oriented so that they are visible from top and bottom views of the member 40. In cases where the members 40 are used as columns 20, the specific orientation of the panels 42 is not as critical. It is contemplated that the columns 20 have the panels 42 oriented both parallel to, and transverse to the orientation of the panels of the beams 16.
Referring now to FIG. 4, another embodiment of the present member 40 is designated 60. Elements of the member 60 shared with the member 40 are designated with the identical reference numbers. A main distinctive feature of the member 60 is a layer or panel of steel 62 located between adjacent structural cement panels 42. In the member 60 depicted in FIG. 4, the steel panel 62 is positioned in the middle of the member, however other locations are contemplated depending on the application. Also, it is preferred that the steel panel 62 is fastened to the adjacent panels 42 using the chemical adhesive 44 and/or the fasteners 46. In cases where the members 60 are secured together in part by fasteners 46, the steel panel 62 is optionally equipped with suitable throughbores (not shown) for accommodating the passage of the fasteners. The steel panels 62 are preferably fabricated using hot rolled or cold-formed steel of varying thicknesses.
Referring now to FIGS. 4 and 5, since the panels 42 are fabricated from conventional structural cement panels or wallboard panels 42′ used in construction, such panels are manufactured in facilities designed to produce conventional 4 foot×8 foot dimensioned panels. Accordingly, the members 40 have a standard 8 foot length 64. In many building frames 10, it is contemplated that there is a need for members 40, 60 having lengths 64 greater than 8 feet long.
In FIG. 5, an alternate embodiment of the members 40, 60 is generally designated 70. Elements of the member 70 shared with the members 40, 60 are designated with identical reference numbers. A main distinctive feature of the member 70 is that it is configured to have a length 64 greater than 8 feet. This extended length 64 is achieved by providing panels 42 of the at least two layers in varying lengths secured together in lengthwise staggered fashion to provide a member with a length greater than 8 feet long. In other words, the member 70 is created by panels 42 of varying lengths fastened together with sufficient overlap to create a composite with an extended length. More specifically the arrangement forms a “bricklayer” appearance when seen from above, as seen in FIG. 5. It is preferred that an overlap 72 of the top two shown adjacent panels 42 be at least 2 feet to provide a member 70 with sufficient structural strength for use in the building frame 10.
Referring now to FIG. 6, a beam 16 is shown secured to a column 20 made of the members 40, 60, 70. It will be seen that the side edges 56 of the beam 16 are visible from top and bottom views. The structural panels 42 have a considerable compressive and axial strength and upon assembly into the members 40, 60 and 70. Depending on the orientation of the beam 16 to the column 20, suitable straps or brackets 74 are contemplated for securing the connections of the members 40, 60 and 70. Such brackets 74 are secured to the members 40, 60, 70 by suitable fasteners 76.
Referring now to FIG. 7, another embodiment of the present structural member is generally designated 80. Components shared with the members 40, 60, 70 are designated with identical reference numbers. A main distinctive feature of the member 80 is that some of the panels 42 have lengths that extend past an end 82 of the member, forming extensions 84. These extensions 84 are constructed and arranged to engage similar extensions 84 of adjacent members 80 in a tongue and groove relationship. An overlap of the extensions 84 is similar to that described above in FIG. 5 relating to the member 70, and adhesive 44 and/or fasteners 46 are contemplated for securing the overlapping extensions 84. It is understood that the embodiment of member 80 is compatible with the members 40, 60 and 70.
Referring now to FIG. 8, another embodiment of the present structural member is generally designated 90. Components shared with the members 40, 60, 70, 80 are designated with identical reference numbers. A main distinctive feature of the structural member 90 is that gaps or spaces 92 are contemplated within the member that are created by using panels 42 of varying lengths. Such gaps or spaces 92 are intended to save cost and/or weight and do not impair the strength of the member. It is understood that the embodiment of member 90 is compatible with the members 40, 60, 70 and 80.
While a particular embodiment of the present structural laminated fiber-reinforced cement beams and columns have been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
Patent Application
20240209617
