US2685194A - Precast concrete framing construction - Google Patents

Description

Aug. 3, 1954 AJAMIRIKIAN PRECAST CONCRETE FRAMING CONSTRUCTION Filed March 10, 1947 4 Sheets-Sheet 1 ian iri

flrsham Am A. AMIRIKIAN PRECAST CONCRETE FRAMING CONSTRUCTION Filed MarcHlO, 1947 Aug. 3, 1954 4 Sheets-Sheet 2 flrrsham I .Hmz'rik ian A. AMIRIKIAN PRECAST CONCRETE FRAMING CONSTRUCTION 4 Sheets-Sheet 3 we way Aug. 3, 1954 Filed March 10,1947

Aug. 3, 1954 A. AMlRlKlAN v PRECAST CONCRETE FRAMING CONSTRUCTION 4 Sheets-Sheet 4 Filed March 10, 1947 flr'sh am Hmiriliian Patented Aug. 3, 1954 UNITED STATES TENT OFFICE PRECAST CONCRETE FRAMING (Granted under Title 35, U. S. Code (1952),

see. 266) 4 Claims.

This invention relates to pre-cast concrete or other molded plastic material construction and more especially to the construction of supporting structures of pre-cast concrete or other plastic molded material, comprising beams, girders, columns, frames, ribs or the like supporting structures.

In the past the supporting structures for floors, roofs, walls and like parts of a building or structure have been built either of poured-in-place concrete or of other materials such as steel, timber, or masonry. It is the main object of this invention to provide a load sustaining space framing construction which embodies all of the advantages of reinforced concrete construction regarding permanency, fireproofing and lower maintenance costs, as Well as all of the benefits of prefabrication regarding savings in material, lower costs of production and speedier erection. According to the invention, I provide a plurality of pre-cast preferably reinforced concrete or other molded plastic channel-shaped or troughshaped elements which are adaptable for easy casting with the depth or transverse extent of the webs thereof made in conformity with any desired elevational outline of the element.

A further object of the invention is to provide a framing construction in which the channelshaped elements are directly coupled together to form box-like hollow segments or members which are of lighter weight as compared with solid sections of comparable strength.

Another object of the invention is to provide novel types of end joint splice whereby a plurality of hollow segments are assembled to form a beam or girder, bent or frame, or an arch rib, or the like supporting structural assembly possessing full continuity for the imposed load stress path or transfer.

Other objects of the invention are the provision of hollow vertical web rib or frame members, including a vertical web frame member having an axis disposed at an angle to an axis of another of said vertical web frame members, and the provision of a vertical web frame member having portions of its axis at an angle to each other, and the provision of a rigid frame of said vertical web frame members including a vertical web frame member having an axis disposed substantially horizontally and a vertical web frame member having an axis disposed substantially vertically, the rigid frame vertical web structure being constructed to resist forces acting along axes substantially normal to each other.

A further object of the invention is to provide the vertical web rib or frame members and the rigid frame structure including said vertical web frame members in which the mean plane of the joint between the channel sections comprising said hollow vertical web rib or frame members is disposed substantially vertically.

With these and other objects in view which will hereinafter appear, I have invented the construction and framing assembly described in the specification and illustrated in the accompanying drawings which are exemplary of the invention.

Referring to the drawings:

Fig. 1 shows an elevational view of the left half of a two-legged rigid bent comprising a girder and two leg or column segments and two connecting or corner knee segments in erected condition prior to final grouting.

Fig. 1a is a vertical sectional view of the right half of the same assembly after grouting, taken substantially on the lines |ala of Fig. 2 and laela of Fig. 5.

Fig. 2 is a cross-section substantially on line 2-2 of Fig. 1 showing the two channel-shaped elements and one method of fastening.

Fig. 3 shows the details of the connector assembly.

Fig. 4 shows an alternative assembly construction, especially applicable to beams and struts of small depth.

Fig. 5 shows a partial cross-section of the joint between the leg or column and knee segments, substantially on the line 5-5 of Fig. 1, and line 5-5 of Fig. 6.

Fig. 6 shows the detail of the erection hinge assembly at the same joint.

Fig. '7 is a longitudinal section of a beam or girder, continuous over a plurality of supports, constructed in accordance with this invention, and including girder segments or portions and header or T-cap segments or portions.

Fig. 8 is an elevational view of the splice be- Fig. 13 is a longitudinal vertical section at one of the joints of the arch ribbing, substantially on line l3-l3 of Fig. 14.

Fig. 14 is a vertical cross-section adjacent one of the joints, substantially on line i li4 of Fig. 13.

Fig. 15 is a horizontal cross-section at one of the joints, substantially on line ll5 of Fig 13.

Fig. 16 shows the connecting details at the abutments of the arch rib.

Fig. 17 is a perspective view of a framing assembly consisting of a column, a header or T- cap segment and two struts constructed according to the invention.

Fig. 18 is an enlarged perspective view of the same assembly with component members separated to show the manner of the jointing.

An essential feature embodied in this invention consists of the provision of reinforced channelshaped elements I, which are pre-fabricated or pre-cast, desirably in a horizontal position of the web, at a suitable plant, or at the site of the construction, and which, according to the invention, are assembled in pairs by bolts 2 to form substantially hollow segments or members, as shown in Figs. 1 and 2. The hollow segments thus formed are particularly adapted to sustain load applied against (substantially normal to) the wall formed by the channel flanges or against the ends of the hollow segments or members, and which are thus particularly adapted to be disposed in a rigid frame or rib structure or assembly with the channel webs of the hollow segments or members in substantially vertical planes and with the mean plane of the joint between the channel elements disposed substantially vertically. The channel webs of the segments or members are desirably always disposed in a plane in which the maximum bending stress is applied.

The channel-shaped element I of the present invention has several characteristic features. One of these concerns its depth or transverse Web extent or distance between the flanges. Although in many of the hollow segments or members of the present invention the dimension in depth or transverse web distance may be constant, such as in the mid-girder and leg or column segments of the bent shown in Fig. l, in others it is varied, according to the invention, as in a straight or curved or tapered section, such as in the straight tapered haunched segments over the interior supports of the girder shown in Fig. '1'. Another feature concerns the outline of the channel web in the longitudinal direction, following a straight, curved, tapered, or angular course, as illustrated respectively by the straight segments of the bent in Fig. 1 and the girder in Fig. 7, the curved segments of the arch rib in Fig. 11, and the tapered, divergent and axially angular segments of the bent or knee in Fig. 1, and of the haunch in Figs. 7 and 18. These variations in depth and direction, according to the invention, preferably conform to the stress pattern of the members of the assembly and thus assure a most economical design.

While in general the walls of the elements are continuous and solid, in some cases they may also have suitable openings 29 and 2! in the web or flanges, as in Figs. 1 and 18, for connection with another framing member, such as a strut or column, or openings 26 and 22, as in Figs. 1 and 17, for placing the joint grout or other desirably semi-liquid moldable bonding material.

Another characteristic or feature of the present invention concerns the bolting arrangement of the structure. In order to provide a ready means of matching a pair of channel elements, a pipe sleeve 3 is cast integrally with the element at or near each flange, and through which sleeve the coupling bolts 2 penetrate as indicated in Figs. 2 and 3 preferably with suitable end washers 2a. The pipe sleeves 3 each desirably having a bearing plate 4 at the inner or abutting ends, preferably welded to the sleeves 3 and which is preferably inclined, as shown. When the depth of the channel Web is too small to require two lines of bolting, a single line of bolts, placed preferably at mid-height, may be used, in which case pipe sleeves may preferably be omitted from the webs and a wood block separator 5 may be used in coupling the two channels I, as indicated in Fig. 4.

The matching edges 6 of the channel flanges are preferably chamfered to provide a partial transfer of loading from one channel element or unit of the hollow segment onto the other by direct bearing, and also for providing a more pleasing appearance of the rib or member in exposed positions. The bearing plates l of the bolt receiving sleeves 3 are disposed to conform to and seat upon the matching edges 6 of the channel flanges. However, the invention is not limited to the matching channel edges being chamfered and to the bearing plates being inclined, as it is readily apparent that the matching edges and bearing plates may be straight and free from any inclination, within the scope of the invention.

The reinforcing of the channel-shaped ele ments preferably consists of wire fabric 7, desirably in channel or trough shape, located in the web and the flanges, and longitudinal reinforcing bars 8 located in the top and bottom flanges. In addition, the webs are preferably reinforced with web diaphragms 8 of reinforced concrete or other molded plastic material disposed near the ends of the channel elements or at other locations thereon as needed by design requirements for stiffening the web of the element during handling or under load, and also to limit and define the splice pocket which is filled with grout or the like moldable bonding material in forming the end joints between the members as hereinafter more fully described. Reinforcing members are preferably provided in the diaphragms as indicated at 9a.

The channel elements 1 are cast or molded to desired lengths and paired to form the hollow segments which are assembled together at their ends by means of special splicing means illustrated by Figs. 8, 10, 15 and 13. In general, the splices are located at points of inflection, that is, at zones of minimum flexural stress. With the arrangement according to the invention, a structure such as a frame or rib is comprised of or subdivided into a series of component segments or members, as described, shaped in elevational View as a rectangle, a trapezoid, a circular or arcuate segment, an L or a T. The forms of splicing means indicated in Figs. 8 and 10 are applicable for end splices between two segments positioned substantially horizontally as indicated in Figs. 1, '7, l7 and 18. For this purpose the ends of the webs of each of the abutting hollow segments are preferably so formed as to provide a longitudinal seat or step I! desirably with an adjoining inclined surface it], thus providing a temporary seat at the steps H for the comple mentary adjacent segments during assembly and erection, and also providing accessibility at the wedge-shaped spaces formed between the in ned su face '0 a d. h nds of th m mentary segments, for splicing the reinforcing bars 8 which project from the ends of the segments and for completing the joint. The bars 8 may desirably be welded together directly by either lapped .or butt welding 12, or indirectly by means of a splice plate or bar 25, or by means of a rod such as is shown in Fig. 15, after which the wedge-shaped gap is closed by cement mortar or the like applied within the splice pocket. As an alternative to the welded arrangement, the projecting rodsB may be anchored by looping into the splice pocket between the ends of the hollow segments, and then filling the splice pocket by cement mortar, as indicated in Fig. 10. The webs adjacent the step joint H are preferably provided with hook bar reinforcements l3, as indicated in Figs. 3 and 9.

When using th welded arrangement, in order to reduce the dead weight of the splice fill, in some Qases it may be desirable to confine the grout fill only to webs and flanges of the spliced channels. This can be accomplished by placing a suitable form assembly within the pocket and in contact with the inside faces of the respective webs and flanges and by applying pressure grout or the like to form the desired closure on all four faces of the joint.

In the case of splices between segments positioned vertically or on a slope, such as the joints in the legs of the bent shown in Fig. 1 and the joints of the arch rib shown in Fig. 11, the detail of Figs. 5, 13, 14 and 15 may desirably be used. This consists of erection hinges cast in the webs of abutting hollow segments and composed of semi-cylindrical members [4 and [5, one cast in each of the abutting segment webs, a base plate 16 and anchorage bars I! as shown in Fig. 6. The ends of the webs of the segments having the erection hinge mem, bers cast therein, are preferably extended beyond the flanges, as indicated in Figs. 1, 13 and 16. The reinforcing bars 8 project from the flanges and anchor into the joint PQQliet I9 desirably by lapping as in Figs. 1 and 5 or by additional splice bar as in Figs. 13 to 15, the said pocket then being filled with cement grout or the like bonding material, as indicated in Figs. 1, 5, 13, 14, 15 and 16, suitable exterior forms being employed as needed.

A similar joint is also utilized at the abutments of the arch rib as shown in Fig. 16.

The assembly of a pro-cast concrete supporting structure according to the invention, such as a hollow ribbing or framing structure, is accomplished by assembling together the two channel elements of each segment or member of the structure, erecting the segments or members, with the webs substantially vertical, into position to form the structure, such as a rigid frame or rib support, and joining the members or segments together by the splicing means to complete the assembly of the framing structure. It is apparent that the structure according to the invention involves the hollow vertical web rib or frame members, including a vertical web frame. member having an axis disposed at an angle to an axis of another of said vertical web frame members, and involves a said vertical web frame member having portions of its axis at an angle to each other. The structure according to the invention also involves a rigid frame of said vertical web frame members including a member having an axis disposed substantially horizontally and a vertical web frame member having an axis disposed substantially vertically, said rig-id frame vertical web struc: ture being constructed to resist forces afiting along axes substantially normal to each other. Suitable means such as hoists, and erection braces and props, as required, are employed in erection of the segments, it being apparent that a desirable, erection procedure comprises erection of the column segments, the header Ts or Ls, the struts, and the girders, and thereafter making the splices between them as described, in the case of a structure such as illustrated in Figs. 1 and 7, or the like. A similar procedure is followed in the caseof an arch r-ib as illustrated in connection with Fig. 11. some joints may be omitted by making segments on e The column segments are suitably secured to the floor by means of floor stubs or pedestals or column recesses, as indicated, desirably provided with upwardly projecting reinforcing received within the hollow column member and secured by concrete or the like filling and bonding material introduced through a suitable opening 26 in a side wall of the column member or segment, as indicated in Fig. 1a.

The connections of the columns and/or struts to a header or T-cap or knee segment are con-. veniently made by anchorage of the projecting reinforcing of the connected elements into the joint pockets, as indicated in Figs. 17 and 18. For this purpose suitable epenings 20 and Z! are provided, respectively, in the web and in the wall formed by the flanges of the header and knee segments for the passage of the projecting reinforcing 23 of the struts and columns, after which the joint pocket I9 is filled with grout or the like through a hole 22 in the top flange, as shown in Fig. 17. The bottom ledge 24 of the opening 29 in the web serves as a temporary erection seat for the bottom flange of the strut, which strut preferably will extend to the inner face of the web, while the rein-. forcing 23 will project into the pocket H) to furnish the desired anchorage. In the case of the column connection, the opening 2| in the wall formed by the flanges is so proportioned that while it allows passage for the reinforcing 23 of the column, it is preferably made smaller than the column section in order that the lower wall formed by the flanges of the header or T-.- cap may seat on the upper edges of the column and thus facilitate theassembly and erection.

It will be apparent that various changes and modifications may be made in the structural embodiments of the invention, without departing from the spirit and scope of the invention, as to which reference is made to the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. A substantially hollow structural framing support member comprising a pair of complementary pro-cast framing support channel elements each including a web and flanges adjoining the edges of the web, said pre-cast framing support channel elements of said hollow framing support member being secured together with edge faces of their flanges facing each other, the said webs of said pre-cast framing support channel elements constituting opposite web side walls of said hollow structural framing support member, an end of said substantially hollow structural framing support member being provided with a structure for splicing comprising corresponding end seat portions formed in the ends of said opposite web side walls of said hollow member, said corresponding end seat portions extending longitudinally inwardly of the ends of said opposite web side walls, and corresponding inclined end portions of said opposite web side walls adjoining and inclining away from the inner extremities of said longitudinal end seat portions and joining an end face of the adjacent flange which is correspondingly shortened, said pre-cast framing support channel elements each having a diaphragm extending transversely thereof near to but inwardly of the said end splicing structure of said substantially hollow member and having an edge facing outwardly of the channel, corresponding transvers diaphragms of said pre-cast framing support channel elements being in alignment with their outwardly facing edges facing each other and constituting a diaphragm wall of said hollow structural framing support member near to but inwardly of the said end splicing structure of said substantially hollow member to limit and define a splice pocket in said end of said member.

2. In a structural framing assembly comprising a plurality of structural framing support members, with adjoining ends of said members secured together, each of said plurality of structural framing support members being of substantially hollow form and each comprising a pair of complementary pre-cast structural framing support channel elements secured together with the edge faces of their flanges facing each other, the webs of said pre-oast structural framing support channel elements constituting opposite web side walls of said hollow framing support members, said opposite web side walls being disposed vertically throughout the structural framing assembly, corresponding end seat portions formed in the ends of the said opposite vertical web side walls of each of a pair of endwise adjoining hollow framing support members, said end seat portions extending substantially longitudinally inwardly of the ends of the vertical web side walls, the longitudinal end seat portions of each of said pair of hollow members being disposed in seating engagement with those of the other, each of said pair of hollow members having corresponding inclined end portions of the vertical web side walls thereof adjoining and inclining away from the inner eX tremities of the said longitudinal end seat portions thereof and joining the end faces of the adjacent flanges thereof which are correspondingly shortened, thereby providing a wedge shaped space between the said inclined end portions of the vertical web side walls and the ends of the vertical web side walls of the complementary hollow member of said pair, said wedge shaped spaces being disposed one at either side of the said longitudinal seat of said pair of hollow members, and bonding material filling said spaces and extending within the ends of said pair of endwise adjoining hollow members.

3. In a structural framing assembly according to claim 2, said pair of endwise adjoining hollow framing support members each having a diaphragm wall extending transversely thereof near to but inwardly of the end of the member and defining a splice pocket and providing an abutting diaphragm wall for said bonding material.

4. In a structural framing assembly according to claim 2, reinforcing means extending from the ends of said pair of endwise adjoining hollow framing support members and extending into the bonding material in said spaces.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 798,486 Aylett Aug. 29, 1905 1,083,876 Craig Jan, 6, 1914 1,182,872 Darrow May 9, 1916 1,734,392 Moore Nov. 5, 1929 1,757,077 Eiserloh May 6, 1930 2,413,562 Henderson Dec. 31, 1946 FOREIGN PATENTS Number Country Date 325,505 France 1902 71,429 Switzerland 1916 159,066 Great Britain Feb. 24, 1921 640,518 France 1928 277,038 Italy 1930 299,903 Italy 1932 556,103 Great Britain 1944 562,698 Great Britain 1944 566,510 Great Britain Jan, 2, 1945

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