US1799400A - Building construction - Google Patents

Description

A ril 7, 1931. E.- A. TUKER BUILDING CONSTRUCTION Filed March .19, 1928 2 Sheets-Sheet m//lllllllll/l/lllll/l/fll//llll//llllllllllll/ll/lllll/l April 7, 1931. E. `A. TUCKER BUILDING CONSTRUCTON 2 Shets-Sheet 2 Filed March l 1928 Eduard c/l Tac'er Patented Apr. 7, 1931 UNITED sTATEs VPATENT'; 'o ca EDWARD At TUCKER, or wINoHnsrEa MASSAHUSETTS B'UILIDING CONSTRUCTION r Application filed March 19, 1928'. Serial Nol 262324.

This invention'relates. to building construction and morep'articularly to concrete floor or roof constructionfor buildings where moderateloads prevail, and'where 'a fireproof or fire resisting structure is de'sired, involving the necessary 'use of steel floor members, and is designed to provide a Construction ineX- pensive to install, economical in .the amount of steel and concrete required', and characv w terized by a marked reduction for any given tween the main supporting members, the

latter consisting of steel beams, fabricated sections, or trusses supported upon columns, girders or masonry walls. This type of floor Construction is costly, in'that'it requires the employment 'of a` large plant, skilled and expensive labor, and costly forms which are no part of the permanent structure and are waste material When lumberis employed.`

To provide a system where temporary :forms and the eXpense incidental theretomay leads, a second type of floorconstructon has been utilized employing relatively light steel floor members, usualyilight-rolled steel sections or sections made of pressed steel, or light steel trusses spaced closely together to approximate the spacing of wood joists. Stifiened metal lath material is then laid over the tops of the steel floor members spanning 'the intervening bays, the concrete forming the floor being poured in place over the lath r material and the latter serving both as a form' and a partially reinforcing element in the completed slab. The operation of installing a floor by this system is economical to the r be dispensed with, and having particular.

applcaton to structures carrying moderate extent that the eXpense of form work avoided, a lesser amount of skilledlabor is 'required and a certain amount of'concrete p is saved. To provide proper bridging support, however, for the metal lath. and the con-; crete poured thereon the spacng of the steel beams is limited to relatively narrow spans, and, because of these limitations in the spacing of the steel beams, the total amount of steel required is so great as to 'become in many instances a serious economical drawback i v In the type of Construction he-rein described, the floor or that part of'it which is ,relied upon to carry the load is formed by a large number of pre-cast reinforced concrete members each relatively long as' compared with its width and thickness, these being brought to the job from their place of manufacture andlaid upon the tops of the light steel beams and secured each individually thereto; This Construction provides an economical 'method of installation not only by avoiding the use of forms but alsothe expense incidental to pouring into place the concrete forming the load su ortin or-` tion of the floor slab. PP p The pre-cast `members furthermore'are so T constructed, and in their assemblage so relatedto each other and to the steel floor beams, that the 'spacing of the latter may be greatly increased, resultingas compared withthe sec-` ond method above'described in a substantial i saving per unit offloor area both of steel and of concrete in the' floor slab, a morerigidly braced floor support, and a composite'floor of greater resilience than 'is possible with a 7 poured-in-place slab.

The invention will be best understood by reference to the 'following descriptionwhen u taken in connection with the accompanying illustraton of one specific embodment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawingszv y Figure 1 is a plan View showing a flooring area constru'cted according to my invention with the pre-cast members laid upon and fastened to the floor supporting beams, the'fin- 10 ished floor and cement base therefor not beingrshown;

ig. 2 is a section in elevation on an enlarged scale taken on the line 2-2 in Fig. 1 transverse to the floor beams and showing both the finished flooring and ceiling;

Fig. 3 is an end elevation in partial section showing one form of a reinforced, planit-like, pre-cast, concrete member which may be employed in connection with the described floor Construction Fig. 4: is an end elevation in partial section of the member shown in Fig. 3;

v Fig. 5 is a sectional detal on an enlarged scale taken on the line 5-5 in Fig. lshowing the method of securing the ends of each precast member to the underlying beam ;e i F Fig. 6 is a plan View of theparts shown in ig. 7 is a section on an enlarged scale taken on the line 7-7 in F ig. 1 showing the side clips or anchors for fastening the sides of the pre-cast floor members to the floor beams;

Fig. 8 is a similar vsectional detail 'taken on the line 8--8 in Fig. 1; and

Fig.9 is a perspective view of the side clip illustrated in F igs. 7 and 8.

Referring to the drawings and to the illustrative embodment of the invention therein disclosed there are shown in Figs. 1 and 2 a portion of a floor Construction in which there are employed the spaced floor supporting beams 11 in arallel arrangement similar to that of wooden; joists but spacedapart by a substantal distance. Herein these beams are each in the form of a solid web, rolled I-beam of very light weight section, but, in

place thereof, floor supporting beams in the storm of fabricated sections or trusses of suitable weight .andvsimilarly spaced might be employed and such members I have termed generically floor beams. These floor beams may bej supported by columns, girders or masonry walls as desired.

The load supporting portionof the floor is composed of a plurality of relatively long thin .and narrow, reinforced, pre-cast members 13 laid across the top flangesof the floor beams, having hearing thereon and Secured thereto in accordance with the system hereinafter referred to.

The pre-cast floor members are preferably constructed in proportions resembling those of wooden p1anks,-lon`g enough to span two or more (herein three) of the bays between the floor beams, thin and' narrow enough to be readly handled, and so reinforced longitudinally as to enable them to withstand not only the deflectionincdental to the sustentation of the intended floor load but also such as 'may arise from their dead weight in transportation or handling.

is distributed throughout substantially the entire cross-section of these concrete planks so as to provide a member capable of taking elongation in each Component layer or plane thereof in amanner resemblingthatofa homogeneous beam and capable 01: eXperiencing an extreme or abnormal deflection without detriment.

i In the illustrated embodiment of the inven- ,tion the concrete planks are constructed and reinforced as described in my prior Patent No. 1,530,630 dated March 24, 1925, the longitudinal reinforcing wires 15 (Figs. 3 and 4) being arranged ina plurality of layers (herein six) symmetrically with relation to the neutral axis of the plank and with intermediate transverse separating wires 17 all proportioned and related' according to the principles disclosed in the said patent. This provides a pre-east concrete plank, thin, compact and light, but capable of carrying deflection without detriment and of standing up under all normal floor leads required in structures of the class indicated.

To serve as a specific example the pre-cast concrete plank shown in the drawings may be twelve feet long, ten inches wide and one and three-eighths inches thick presenting a ratio of length to thickness of approximately one hundred and five to one, and capable of spanning three of the bays between the floor beams 11, which latter may be spaced four feet apart on Centers. It will be understood that these dimensional e-Xamples are illustrative only.

' In constructing the described form of floor the pre-cast concrete planks having been previously formed and transported to the job, are laid side by side' across the top flanges of the floor beams, being preferably spaced apart at their sides and ends by a small gap which, for example, may be one-quarter of an inch but is susceptible of wide variatien. These gaps or joints are subsequently sealed by filling with cement, grout or mortar bonding the units together and making a tight continuous floor slab. The separation of the planks by the width of the joint permits se curing a true alignment of the planks and .tends to tie the planks together by an interfloor beams (Fig. 1) so that each beam is overlapped by one or more (herein two) of adjacent planks.

If desired, the sides of each plank may be beveled inwardly and upwardly, instead of being straight as shown in Fig. 8, so that the sides of adjacent planls diverge upwardly at a slight angle serving to make the mat which forms the finished floor as subsequenty described, more effective in distributing any concentrated loads over adjacent planks because o' the weclge-shaped oint.

Each plank is anchorcd or Secured to each underlying floor beam on which it has bearing by suitable fastening means which herein comprise side clips 19, for fastening together the plank and each floor beam overlapped thereby, and end clips 21 for fastening together the end of the plank and the beam on which it rests.

Each'side clip (Figs. 7 8 and 9) consists of a flanged plate 19 adapted to overlie the upper edge of the plank and extending at right angles from the upright portion 25 which passes down at the side of the plank through the gap or joint between'the 'same and the next adjacent plank and carries at its lower end the extension* plate 27 which is *forced into' gripping engagem'cnt with the under side of the flange 29 of the floor bean 11. v The ends of the planks are anchored to 'the floor beam on which they rest by means of the' end clips shown in Figs. 5 and& Each clip comprises a U-shaped member 21 fitting over the end of the plank, the latter being re'- cessed at 31 on its under side to receive the lower leg of the U, so that a full direct bearing of the plank on the floor beam may be assured; Abutting or opposing edges of the two aligned planks are anchorecl by adj acent clips arranged at opposite sides of the medial line of the planks. The lower leg of each clip has a reverse bend 33 which is forced into gripping engagement with the under face of the flange of the floor beam so that the end of the plank is rgidly held with relation v to the beam.

i The holding clips are preferably arranged according tosome system such as that illustrated in Fig. 1, so that while each plank is" anchored* to each floor beam, the end and the' side anchors for any one floor beam are distrbuted along the same at spaced ntervals.

'The descrbed Construction of fasteni'ng devices and the arrangement thereofnot only holds theconcreteplanks down to a bear-ing on the floor beams so that a full hearing is, preserved at all times by the planks on the floor beams irrespective of the application of a concentrated load at any single bay, but it also enables the planks themselves to serve as a multiplicity of lateral braces forthe floor beams preventing any buckling of' the top flange of the steel floor beams thereby adding materially to the rigidity and strength of the composite floor.

This rigid bracing is materially increased :by arranging the planks so that each cne spans at least two o'fthe bays intermediate the floor beams. i I

To complete the finished floor, the end and side joints between the planks are filled. with cement or the likeand a top' floor finish is added preferablyby'applying a shallow cement finish 35 (Fig of suflicient depth to cover the upper eXposed portions of the end clips 21 and side clipsl9 and of such additional depth only as may be required for the character of surface finish to be applied. This not only serves to bond together the pre cast units but to bond to the resulting continuous slab the fastenings between the indi vidual units' and the beams. In Fig. 2 there is shown a 'surface finish 37which may be of i linoleumor other composition laid directly .on the cement finish, but, if desired, wooden screeds may be embedded in the surfacecement35 to receve a wooden floorng'or a nailing concrete may be used for the finish 35to floor and the particular Construction of floor finish applied to the top thereof is immaterial. V a

Tie wires 39 (Fig. 2) to serve as bridgin y for erection use may be employed'if desirec between the floor beams,-such bridging wires being located so that they are located within" the joints between the concrete planks. i

full fireproot, may be employed in 'connection with the described floor Construction. I have herein shown a ceiling Construction comprising pre-cast gypsum or reinforced concrete slabs 4-1 applied to the under side of the floor beams and reinforced, held in place by the fastening wires4c3` secured to thelower web of the floor beams holding the supporty v ing rods 45 which underlie thelslabs 41. 'The underside of the ceiling slab-l has applied thereto the finishing plaster cover-ing &7;

The use of the pre-cast members' in lengths suflicient to carry over two or more bays, and arranged so as to break the ]o1nts on staggered Any desired 'type of ceiling, either part or lines, combined with the clips or anchors to i the steel floor-beams, causesth'e floorto act as a unit and, whileprovidng a floor-havinga greater resilience than is possible with a poured-in-place slab, aflords a 'continuity p similar to'that secured by a monolithic slab,

This feature not only causes the'floor to act as a unit, but provides a continuous tie between' the walls of the structure and the continuously-tied floor itself This system of Construction, especially for cases involving moderate loads, provides an nexpensve floor Construction of lght weight,

low deadload, with themost economical dis-'I' tribution otsteel between the floor beams and i the reinforced 'floor membersand aminimum a amount of concrete or the load to be carred,

:and with the floor beams laterally braced to a degree not obtainable by any other type of 'about one twenty-fifth of the width of the span, and in any event cannot be reduced to anything comparable with the permissble thickness of the described form of concrete plank, becomes so great as to provide a dead load far in excess ot' anything required in the Construction herein described. Furthermore, t-he standard sections of steel beams are so designed that their `full strength cannot be developed under general conditions ercept by a spacing requirng a slabof at least four inches in thickness and oftener a wider spacing and greater thckness These Constructions, therefore, lead to an increase in dead Weight and a design which is a compromise between loss of economy in the steel design and loss of economy in the dead weight.

In the floor Construction previously described, where the slab is poured 'in place on metal lathing or the like, the metal beams must be spaced closely together, resulting in an uneconomical use of the steel, especially where I-beams are employed, and resulting also in a slab which must have a minimum e depth yielding a ratio of slab thickness to the span seldom more than one to ten or one to fifteen, thereby producing a large dead load as well as a structurally poor floor ineffecti'vely reinforced. r

In the herein described Construction, the low weight and thickness of the well-reinforced, pre-cast unit permits the use of steel floor beams of light weight but with `their fullstrength developed, which beams could not be used with the excessive dead weight of a poured-in-slab, such light .weight beams being spaced at distances impossibleto provide forms, no plant to install and no especially skilled labor. By suitably disposing the reinforcement in' the pre-cast member, concrete planks m y be constructed capable of carrying a load which, in a poured-in-place concrete slab, would require a depth of concrete, and consequently yield a dead weight, several times greater.` It there'ore becomes possible to space the light weight steel beams fai-ther apart than has been previously possible in the 'metal lath Construction rcducing the aggregate amount oi' steel comprised in the floor beams and the floor slab in some instances by or more, and the total weight of concrete in some instances by thereby reducing the eXpense, the dead weight carried and providing a more rigid, less expensive and more easily 'constructed floor.

Each pre-cast floor plank is preferably 'fully cured or set before being laid and, be-

cause the load supporting portion of the floor consists of a multiplcity of such planks, there are eliminated any internal stresses in the floor which frequently develop in 'the case of a continuous poured-in-place slab, in which such internal stresses, set up through shrinkage, expansion and contraction arisingin the process of curing or setting, may be a source of weakness in the slab and the supporting steel iframe.

While for purposes of illustration I have herein described one specific .type of floor Construction with specific dimensional relations, it is to be understood that these details are illustrative only and that the principles underlying my invention may be applied in widely differing form and to purposes other than that herein illustrated in detail.

Claims- 1. A building Construction comprising a plurality of spaced steel beams and a loadsupporting slab carried thereby the same "comprising a plurality of separate pre-cast remforced concrete plank-like members of relatively great length as Compared with the thickness, said members being laid transversely across said beams, each plank spanning a plurality of the intermediate bays and having its. ends and one or more intermediate portions hearing on said beams, means for fastening each plank to each beam on which it has hearing means for bonding together said members to form a continuous composite slab. 4 v

2. A building Construction comprising a pluralty of spaced steel beamsand a loadsupporting slab carried thereby, the same comprising a plurality of separate pre-cast reinforced concrete plank-like members laid transversely across and 'hearing' on said beams, each member spanning a plurality of the intermediate bays and having a ratio of length to thickness not less than fifty to one, means for fasteningeach individual member to eachbeam on which it has hearing and means for bonding together the said members to form a continuous composite slab, said slab andbeams serving mutually to renforce each other,

3. A building Construction comprising a plurality ofspaced steel beams, and a continuous composite slab supported by said beams comprising a pluralty of pre-cast reinforced concrete members of relatively great length as Compared with thickness each member spanning a plurality of bays intermediate said beams, means for' fastening eachof said members to underlying beams to cause the slab and beams mutually'to reinforce each other.

4. A building Construction comprising 'a plurality of spaced steel beams a load-supporting slab' carried thereby comprising a plurality of pre-cast heavily reinfcrced concrete plank-lke members capable of elongation in each Component layer in a manner resembling that characteristic of a homogeneous beam said members being arranged transversely said beams and spanning a plurality of bays intermediate the beams and having bearing thereon and means for securing each of said members to each beamon which it has hearing; I

5. A building construction comprising a plurality of spaced steel beams and a slab supported thereby comprising a plurality of separate pre-cast concrete members of relatvely great length as Compared With thickness laid transversely on the steel beams and fastened each thereto, each member spanning a plurality of bays intermediatethe beams and each member being reinforced by` a plue rality of layers of longitudinal reinforcement distributed through-out its cross-section on opposite sdes of itsneutral aXis.

6. A building Construction comprisinga plurality of spaced steel beams and a slab supported thereby comprising a plurality of separate pre-cast concrete membershaving a ratio of length to thickness of not less than fifty to one laid transversely on the steel beams and fastened each thereto, each member spanning a plurality of bays intermediate the beams and each member being reinforced by a plurality of 'layers of longitudinal reinforcement distributed through,- out its cross-section neutral aXis,

7. A building Construction comprising a plurality of spaced steel beams and a continuous composite load-supporting slab carried thereby, thesame comprsng a plurality of separate, pre-cast, reinforced c'oncrete members of relatively great length as compared with thickness, said members each spanning in staggered relation a plurality of bays intermediate the beams and means :for securing each member to underlying beams to cause said beams and members mutually' uous composite floor slab structurallyunited to said beams, said slab and beamsserving on opposite sides of its' tively great length as Compared with its i thickness, said members being supported side by side by said beams but separated from each other by a relatively small gap, each member being anchorecl to the underlying beams by fastenings exposed to said gaps and said members spanning each a plurality of bays intermediate said beams, said members having their end joints in staggered relation Whereby each beam is overlapped by one or more adj acent members, and a surface covering of cement filling said gaps and bon-ding together into a contnuous, homogeneous slab. said units and the said astenings.

9. A building Construction comprising a plurality of spaced steel beams and a con-. tinuous composite load-supporting slab carried thereby comprising a plurality of separate pre-cast concrete plank-like members of great length as compared with thickness, said members spanning each a plurality of bays intermediate said beams, the width of the spanned space between'the beams having a rato to the thickness of said members of not less than thirty to one, means for fastening said members to said beams, and means for bonding said members together to form a continuous composite slab.

10. A floor Construction comprising a plurality of spaced steel beams and a continuous composite floor slab structurally united to' said beams, said slab and beams serving muprising a plurality of pre-cast, reinforced, concrete, plank-like members each of relatively great length as compared with its thickness, said members being supported side by side on said beams and spanning each relation a plurality of bays intermediate said beams, said members having their end joints in staggered relation whereby each beam is overlapped by one or more adjacent members, fastenings for anchoring each member to the underlyng beam on which it has bearing, and means for 'bonding together said members into a c-ontinuous homogeneous slab.

In testimony whereof, I have signed my name to this sp'ecification. e EDl/VARD A. TUCKER.

j CERTIFICATE OF GORRECTION.

Patent No. 1,799,40o. Granted April 7, 1931, to

EDWARD A. TUCKER.

certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, lines 106 and 107, claim 10, strike out the word "relation"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signedand sealed this Sth day of May, A. D. 1931.

It is hereby M. J. Moore,

(Seal) Acting Commissioner of Patents.

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