US939642A - Method of constructing and erecting reinforced-concrete beams, girders, and arch-ribs. - Google Patents

Description

' P. W: SKINNBR. STRUGTING AND EREGTING REINFOR METHOD OB CON GED CONCRETE BEAMS, GIRDERS,

' AND ARCH RIBS.

APPLICATION FILED 113.20, 1908,

Patented Nov. 9, 19o9.

2 SHEETS-SHEET 1.

INVENTOR WITNESSES F. W. SKINNER. METHOD OF'CONSTRUCTING AND BREOTING RBINFOR CED CONCRETE BEAMS, GIRDERS,

AND ARCH RIBS. APPLICATION FILED rEB.2o,19os.

Patented Nov. 9, 1909.

2 SHEETS-SHEET 2 WITN ESSES FRANK W. SKINNER, 0F TOMPKINSVILLE, NEW YORK.

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METI-ron oEcoNsTnUcTINe AND ERECTING REINFoRCEncoNoRETE BEAMS, eIRDERs,

To all whomt-maycomern: lSe-it knownthat L'FnaNn M. SKINNER, a citizenof the .United States, residing at No.

5d yShermanavenue, v'lon'iplrinsyille, in the countyHof-- yRiclui-iond fandl State of New York, .havejg inventerba .fn en1 and useful Met-hodyof ,Constructing and Erecting Rieinforced Concrete Arch-Ribs, fication.

Heretofore the beams, girders, and platformuslabspf concrete floors, roofs, and similar structures, h avebeen reinforced with bars of stee l usually designed only to resist the tensile fand` shearing stresses in the finished member, and no t" adapted lfor auxiliary :service in the preliminary 'operations of construct-iemand e1rection, for'which additional,temporary provision iii-ust be made at a fonsiderable expense, i

ln straight beams and girderslhe reint'orcement-generally consists of a plurlity ofwsmalllbars, `more or less liexible, which havelittle resistance to bending and must be supported` during theconstruction of the member, and aret difiicult,f t`o' adjust and maintain in `the required yposition The connection.; betiyeen tension and shearing mem- .Beanis, Grirders,V and bers i's u su ally poor and difficult to make or maintain., l

Nearly or quite all the reinforced concrete beams :and girders heretofore in use requirelthe construction, of falseworkor other support-ing devices to carry the Weight of the reinforcementsteel, the Wet. concrete and the forms,' until the steel and concrete become united by the setting of the latter and the members developlselfsupportingstrength. i

` Y In some instances reinforced concrete beams andggirders have been east in forms on the surface ofthel ground, thus obviating the necessity offalseworlnand afterward assembled together as separate, units of the structure. Oiraccount of the great Weight this 2method is liable to roduce dangerous and injurious stresses an requires a powery ful plant to handle and erect ythe beams and "during constructionv and erectiolnbefore the concrete becomes ser-v iceable, thereby effectf Specicationof Letters Patent.

of which the following is a speci- -.f. .if E 4AND.Anali-nnss.

Patented Nov. 9, 1909.

Applice'tionleid February 20, 1908. Serial No. 416,871.

ing great veconomy and promoting the rapidity and convenience of the work.

Thev diferent portions of the reinforcement intended to resist the tensile and shearing stresses are joined together much more rigidly. positively, accurately, and efficiently than by other methods, and all the' reinforcing steel is in a compact and rigid form which is easily and accurately adjusted, and maintained Without difiiculty, in the required position in the form.

In the construction of beams and girders the `permanent reinforcement steel is combined with temporary. compression pieces which enable it to develop its full tensile and shearing strength to resist erection stresses and eliminate falsework. and the forms for the concrete are attached directly to the self supporting steelwork, thus providing very simple construction, and sometimes the steelwork is utilized to constitute a part or all ot' the form.

The principal lelements of my invention include special forms of reinforcement steel, in frirders, beams, and arch ribs; and the combination of permanent steel tension members with temporary compression members.

Figure l is a cross section at S S, F ig. 2 and Fig. 2 is a side elevation of the reinforcement steel for a reinforced concrete girder. Fig. 3 is a cross section at T T, Fig. 4 and Fig. 4 is a side elevation of the finished girder. Fig. 5 is a cross section at R R, Fig. (S and Fig. 6 is a part side elevation of the steel portion of the girder, as shown in Figs. l and 2. temporarily reinforced with compression 'pieces to resist erection stresses.

Fig. 7 is a transverse Vertical section 'at or archY rib, showing the combination of the concrete, the metal reinforcement; and the separated top flange pieces.

In'all'cases, the same reference numbers are used toi designa-te the same or correspondingparts of different gures.

Iii-Figs. l and 2 the reinforcement correspondsftoan ordinary plate garder Without the top yliange, and with veryhght web stlff steel and concrete.

ener angles, andy is calculated to resist all the tensile orlower ilange stresses, and part of the shear' developed in the completed girder in service, and to insure the exact arrangement and location of the tension metal, its proper connection to the compression member, and the distribution of stresses throughout the finished girder. The ila nge angles 2, 2, are designed to take all the tension due to the moment of ieXure. '.lhc web plate 1, is designed to resist shear, to connect the tension pieces por-ary compression member not here shown, and to engage the concrete with a strong bond by means of the smallvertical angles It isl provided with open holes 4t, 4,

and (l, 6,' and with transverse rods o, 5, the latter designed to give additional bond between the steel. web plate and the` concrete,

that tlie'holes (i, 6, rods 5, 5,

but it is obvious be omitted it suil'icient.

and angles 3, 3, may

adhesion is otherwise secured ln Figs. 3 and Zl, the reinforcement Ishown permanently inclosed in a mass of concrete T, adapted to resist the compressive stresses in the linished girder andv to furnish complete insulation and protection for all the reinforcement steel.` This obviates all necessity for paintingthe steel and nearly or quite eliminates any labor or expense for the maintenance oi the girder a't'ter construction. The concrete belowtlie llaiige angles 2', 2,.nia,y require anchorage it may be wholly omitted, leaving only the lower horizontal surfaces ot the angles exposed. .li anchors are used, they may be similar to bars 5-5, Fig. 1.

In Figs. 5 and 6 the upper part' of the per manent steel web, l, of Figs. 1 and 2, is shown temporarily reinforced by compression pieces 8, 8, secured to it by bolts 9, 9, through the 4holes 4, e. The pieces 8, 8, act asy compression flanges and complete 'the girder with sufficient strength to support its own vdead load and thatdue to the floor system, until the structure is nearly completed, and derives permanent compressive strength from the addition of nearly all oi' ,the co1i crete 7, Fig. 3, which makes it self sustaining and allows the pieces 8 8, to be removed and saved for use in the erection of other gird- 7 by filler pieces ers, thus effecting a great convenience and: economy.-

In Figs-,7 and 8, -the temporary compression pieces corresponding to 8 8, and 6, are spaced out-from the web plate 1` 11 11, which are arranged with spaces 1212, .between them at short intervals providing for the filling in of concrete in the form of which the side pieces 123 13, are secured to the compression pieces 8 8 and the bottom pieces lal are attached to, 13 13, below the iange angles 2 2, thus all'ow ingspace for concrete to inclose the lower 2, 2, with the temi between the to them, or-

iii Figs. 5'

sides of the flange angles. lt is obvious that, it' it is not deemed essential to inclose the' lower surfaces of the flange angles 2 2, with concrete the side pieces 1? 12?), can be moved closer together so as to be in Contact with the edges of 2 2, and can be secured together by or by other means, and the bottom pieces 14 may then be dispensed with. Vln Fig. 9, the detachable top chord pieces 8-S,-are shown embedded in the concrete 7, and the filler pieces 12-12, which separate the top chord pieces 'from each other a'iid from the web 1, are indicated by dotted lines, being hidden behind the concrete.

I claim, y l

, 1. The process of construction of a reinforced concrete beam, girder, or arch rib, by thefollowingsteps; the assembling ot the reinforcement metal -with temporary*85 torni or mold, the filling of the forni or mold with a plastic materia-l, the removal of the temporary compression member after the concrete has developed a set and strength to resist the compression stress in the gire er.

2. The process of construction of a reinforced concrete girdei, arch rib, or beam by a con'ibination ol thit'ollowing steps, as- .sembling a temporary top flange member to the web. so as lo torni a complete girder efficient to support its own weight and add-itional erection loads during construction, supporting the ends of the girder in position required ior the finished structure, inclosing the bottom liange and web members by a form or mold, illin' the form or mol with a' plastic materifl, removing the top llange member, and any temporary portions olt the forni or mold after the developed a set and strength to resist the compression stress in the girder.

3. The process of construction of a reinforced concrete girder, beam, or arch rib, by a combination of the following steps, riveting together a web plate, bottom flange an gies and shearingand bonding angles transverse to the liange angles, assembling top `flange pieces and separators to the web late, attaching a. form or mold. to the top ange pieces, connecting the web plate to supports` at the end adapted to carry the weight of the girder and its load. lilling the :torni or mold with concrete, removing the top flange pieces and any temporary portions oi the fillers and form after the concrete has developed a set and strength to resist the compres on stress in the girder. and filling with concrete any cavities lett by the removal of temporary pieces.

il. The process of f :onstruction of a reinforced concrete beam, girder, or arch rib,

concrete has inclosiire ot' the metal reinforcement with aY llt) by a Combination of tbe f'ooWing steps, as-

sembling together the permanent metal re- :presson member adapted to combine with the permanent metal and form a complete girder eioient to resist construction stresses by` the development of the strength of the permanent steel and the temporary compression member, acting together before Jc he development of compressive strength 1n the concrete; inclosing the permanent relnforcement metal by a form supported by the girder; supporting the girder at the ends only, Without intermediate supports or falsework; filling the form with concrete; and removing the temporary compression mem ber after the concrete has developed strength to resist the compression stresses in the girder. A

Signed at New York city, this 19th day of February 1907.

v FRANK V. SKINNER Witnesses t CI-IAS. V. BUCKNALL, ANDREW BEKEY.

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