US1688128A - moccetti - Google Patents

Description

2 Sheets-Sheet l )MW 7 x, 5 i :.1

By Aiomeys,

WWW-

E MOCCETTI COMPOUND STRUCTURE Filed May 5, 1927 .u no ll Oct. 16, 1928.

Oct. 16, 1928.

E. MOCCETTI COMPOUND STRUCTURE Filed May 5. 1927 2 Sheets-Sheet 2 HUHKIJHHU NN @E By l llorncys,

Patented @et l, i928.

FTFS

nennen Mesones-1r, nacnasnn, LATE or new Yoeri, n. Y., BY LOUISE Moconrrr, anrrrnisraarnrx, or Yoan, n. Y.

COMPOUND STRUCTURE.

Application tiled May 5, 1927. Serial No. 189,052.

The invention relates to improvements in structures made of plastic or any suitable coherent mass in which are embedded or placed metallic reinforcen'ients for tension. The constructions herein disclosed as embodiments of the invention are webbed structures provided with r tensile reinforcements in the zones of greatest tension and special tension reinforcements in the webs. The coherent mass is generally either plain concrete or a combination of concret-e and particular metallic members or reinforcements.

rlhe purpose of the new arrangements and features is to obtain structures of small bulk, light weight and great inter ral strength better suited and more economical in cases of long spans than ordinary reinforced concrete Constr .ctions Various arrangements, de-A scribed herein, contribute independently to this result; however, the present specification emohasizes especiall7 the use of wide and correctly spaced flatwe'b bars in connection with suitable main tensile reinforcement as means of decreasing the bullr and dead weight of compound structures through reduction of the web thickness.

rEhe accompanying figures show only a few examples of the new structures comprising simple girders, a cantilever system and an arch rib, but these structures maybe used in all cases where moments and shears have to he resisted or where axial forces (in tension pression llious structures embodying the inl is a view in side elevation of a der supported at its ends, and Figs. .re cross-sectional views thereof on tom reinrorcement on line lof Fig. l, drawn to larger scale than that of Fi Fig. 5 represents a portion of the lower part of a gil-der provided with two sets of web bars and a main tensileV reinforcement made of riveted shapes, and Figs. 6 and 7 are sectional views thereof taken on the lines 6 6 and T T of Fig. 5.

Fig. 8 is a view in sido elevation of the end part of a girder in which the main tensile reinforcement consists of riveted flat bars, and Fig. 9 is a view in cross-section thereof on the line 9 9 of Fig. 8. i

Fig. l is a view in side elevation of half of a cantilever system, and Figs. ll, 12,13 and ll are enlarged views in cross-section taken on the lines ll-ll, l2`l2, :t3-13, and lll-*14, respectively.

Fig. l is a view in side elevation of one half of an arch rib, Fig. 1G being an enlarged sectional view thereof near the crown, on the line 16-16 of Fig. l5, and Fig. 17 being an enlarged horizontal sectional view of its abutment on the line 17-17 of Fig. 15.

ln order to clearly show the various reinforcements of the structures represent-ed, all metallic parts, although entirely embedded in the coherent mass, have been shown in full lines in Figs. l, 5, 8, l0 and l5, the enveloping part of the structure being represented in broken lines.

An idea of the special features of the present constructions ma be had bv referring .f C

y for instance to the simple girder shown in Figs. l, 2 and 3. The tension reinforcement for this girder may consist of a continuous main tensile reinforcement running along the bottom edge of the gir-der and web bars connected to the main tensile reinforcement. The coherent mass may be concrete in which may be embedded two main steel members for compression running along the upper edge of the `girder and one steel web post above each of the supports and Bj The main tensile reinforcement may be composed of four spaced steel plates j? placed vertically, that is to say, parallel to the plane of the weband separated by concrete (Fig. 2). Transverse bolts shown in their true form in Figs. 2 and l, and represented symbolically by small black circles in Fig. 1,-conneot plates p, said bolts passing through the intervening concrete.

Figs. 5 and 6 show an alternative type of main tensile reinforcement more compact than the preceding one. lt is made of two spaced built-up members separated. by con- .lll

Y ce

crete and connected by transverse bolts b. Each member is composed of two plates p and three angles a riveted together.

The web members F and f (Fig. l) consist of fflat bars whose connections to the main tensile reinforcement have been obtained kby using' for two consecutive web members .one single bar bent so as to form two parallel branches and an intermediate loop and placingthe loop in the central interval between .plates p. vPart of the bolts may conveniently be placed inside the .loops of the web members. The web bars located near the center of Ithe girder maybe vertical. Each of the others may have parts so .inclined as to meet the bottom re forcement at. a angle a of 450 (Fig. l). llhe vertical web members near the center .an d the i-nclined members near the supports may be straight from end to end, while the remaining' ones may be bent at some intermediate point so as to rive their upper ends vertical. directions. The web bars F cover ,the whole vdepth of the girder, `but the bars f are shorter so as to save web metal.

Each of the two continuous liiuil-t-up steel members used in the Zone of greatest compression of the girder may comprise (Fig. 2) a vertical web plate p and four angles c riveted together. The. e members .are embedded in the `concrete at a snilicient distance from each other to permit the upper ends of the web bars F to extendbetween them and are connected by transverse bolts Z) (Figs. l and 2) which pass through the intervening' concrete.

Each of the web posts on the supports A and B (Figs. l and may consist of two channels c connected by transverse bolts Z and embedded in the concrete at a sullicient dis- 4 tance from each other to permit the ends of the web bars nearest to the supports to extend into the intervening concrete filled space. The ends of the web posts may be connected to the top and bottom flange members by rivets or bolts.

,lnfreference to the flange members, the web posts and the connection of the web bars to the tension Vflange members, just described, it must be stated that they represent particular arrangements designed for use in long span bridges; but thin web structures based on the use of flat hars coilnected or -held to a continuous main tensile reinforcement may be obtained with such reinforcen'ients of any suitable type and any suitable coherent mass` As a main tensile reinforcement, rods or bars of any appropriate section steel shapes like angles, plates, channels, I-beams, etc.-laid, arranged, combined or connected in ahy suitable manner,`wi ll answer' the purpose. To improve the bon d or friction between v the main tensile reinforcement and the surrounding' mass, bars or shapes provid-ed with embossed surfaces vin the manner of deforn'ied bars or checkered platesare of assistance. Angles s (Figs, 5 and 6) or other suitable shapes conorally adequate even for thin webs, but when high compression stresses or other causes require a special strengthening' of 'the concrete in the web, steel rods, shapes or members may be used for this purpose.y For the regions of `:greatest compression the reinforcement, when necessary, may be obtained for instance by means of longitudinal bars or steel shapes, transverse ties, hoops, spirals, transverse plates as described i i latent No. QlOlT, or any appropriate combination of these tijf'pesof reinforcement. Blocks of ha rd precast materials may also be ei iployed in the manner shown in the above-mentioned patent.

Continuous structural steel shapes or built up members of comparatively large section and having' a suilicient stillness of their own, independent of the presence .of `the concrete, permit of a considerable augmentation of the resistance of compression flanges and in their mode of action are analogous to 'the steel cores in composite columns. Each of the two builtup members shown in Figs. l and 2 is a member of this latter kind. Greater stillness, if necessary, could be obtained by interconnectingl the members by means of horizontal'lattice bars or short plates; it must be noted here, however, that for correct spacing of the compression flange bolts (Fig. l) these bolts 'in connection with the intervening concrete filling between the builtaip members act in the same manner asa lateral steel bracing'.

Flat bars used as web reinforcements in the manner shown have valuable properties which may be briefly set forth as follows: In a compound structure reinforced inl tension by a main tensile reinforcement having' web bars connected thereto, a favorable and comparativelyv simple distribution of the internal compression stresses in the coherent mass is obtained by usine' closely spaced web bars of aV width equal to the thickness of the web. In this ideal case, the stress distribution in all interior planes parallel to the faces of the web is the same; on the other hand, the tension str' s at any point may be considered as taken by the reinforcement and acting, therefore, in a known direction. Owing to these simplifications it possible, through the study of the mutual deformations of the steel and the coherent mass to deterinine the curves of maximum compression stresses in the coherent mass ,which given clear picture ofV the internal stress distribution and enable the computation of the stress at any point, of the coherent mass or tie reinforcement. Some of the compression curves for the grirder shown in F 1 have been indicated by dotted lines such 3S 72,71 0 7L iin-der Leashes the assumption of a uniform loading over the entire span. The stress along each compression curve varies, but, for a given loading, the curves stand in a fixed relation to the inclinations or curvatures ofthe web bars. lllhen the web members are vertical, the compression curves, as a rule, are comparatively fla ter and make with the main tensile reinforcement a smaller angle ,f3 than when the web members are inclined. ln the cases of vertical bars, the average stresses alongthe compression curves are comparatively high, while for inclined bars the average stresses are comparatively low. vWhen the web members are incurved so as to intersect the compression curves approximately at right angle, both the compression stresses and the elastic eiongations of the web are reduced to minimum values. By proper inclinations or curvatures of the web members it is thus possible to control within certain limits the values of the compression stresses in a web of predetermined thickness. rEhe stress along each web bar is alsovariable and near the mainv tensile reinforcement greater than in the vicinity of the compression edge of the girder. his explains why, as shownA in Fig. l, web metal may be 'saved by using a number of comparative y short bars f.

The web thickness may be determined from L the actual webcompression stresses taking into account, if necessary, the influence of the elastic elongations of the web upon the compressive resistance of the coherent mass. The specific web elongations are maximum in the directions perpendicular to the compression Y curves; they may be lessened by increasing the amount of web metal so as to obtain low steel stresses or by giving the web members directions more nearly perpendicular tothe compression curves or both. Additional web members of suitable length, connected to the main tensile reinforcement may conveniently be used for this purpose.

rlhe metallic web posts in the present structi s are members wnose function is to distribute into the web certain external or internai forces, thereby modifying themode of action of these forces in more favorable or suitable manner. The web posts on supports A and l5 (Figs, l and 3) transmit the support -reretiens partly to the web members connected to them and partly to the coherent mass. The web posts thus prevent the concentration of compression stresses which would otherwise occur in the lower part of the web at the supports if these posts were'omitted without providingl for adequate masses of concrete or coherent mass. An even distribution of the support reactions on the whole depth of the girder is thus obtained *ith consequent reduction of the compression stresses in the coherent mass and increase of the ultimate shear resistance of the girder at the supports.

in connect-ion with plain concrete as cohen ent mass the. present structures have over ordinary concrete constructions reinforced with square or round bars and stirrups two main advantages z First: lllhercas the distribution of the internal stresses in ordinary reinforced concrete girder structures is so complex that the lat-ter can be proportioned only by approximate rules based largely on testsof actual girders, the present constructions canbc proportioned accurately and vvril out such tests from the actual nern al stresses so that, besides obtaining, in all cases, structures of perfectly known resistance, it is possible to utilize the various materials to the extreme safe limit. y

Second: For determined amounts of reinforcement in the tension flange and in the web, the present stress distribution given the least web compression stresses obtainable for a fixed web thickness and given inclinations or curvaturcs of the web members. rJ'Che proselitconstructions permit, therefore, a reduction ot' the web thickness, which is very important in the of great spans.

ln the practical arrangement of the web members careful consideration must be given to the. spacing,tl1e width and the end connections of these members in order to make them fully effective.

As the above simple and favorable web stress dist ibution is based upon the theoretical assumption that every point of the web is endowed with a certain resistance in tenq sion furnished by the web reinforcement, this assumption should be warranted by adequately close spacing of Jcheweb members, bearing in minclthat too widely spaced members will give rise to a different and less favorablestress distribution. As a rough and approximate indication, an average spacing of one-fifth to one-sixth of the depth of the girder between the points where the web bars meet the main tensile reinforcement is close enough to develop the fulll effectiveness of these bars. Such close spacing may of course, if desired, be restricted to certain parts of agirder or structure, thus confining the favorable stress distribution imparted by the flat bars to the regions of the structure where it appears of advantage. In regions of low shear the web reinforcement becomes comparatively unimportant and the spacing of the bars may, of couri e, be considerably greater' than indicated above.

rllhe described web stress distribution rests further on the assumption that the web bars are secured to the main tensile reinforcement. rhis condition may be fulfilled by any arrangement, device or contrivance capable of holding directly or indirectly the web bars firmly to the main tensile reinforcement. Direct connections by means of rivets, bolts, iooks or any suitable ties, may be used. llelding also is adequate. For indirect connections, plates, angles or other suitable los titi

pieces lmay be interposed -between the web bars and the main tensile reinforcement. In the case of main tensile reinforcements made partly or entirely of flat bars, the ends of these bars vmay be bent up into the web to form some off the web members.

Figs. 8 and 9 show ana-rrangement of this latter kind, Sonie of the heavy flat bars p composing the bottoni reinforcement being bent up into the web and the remainder of the web bars riveted to the bottoni reinforcement. It is also possible to build all web bars in one piece with the l ars of the main tensile reinforcement; however, it is not intended to cover herein the ar `angenient in which all web bars are formed by simply bending and extending into the web the flat bars of the main tensile reinforccmentas shown in Patent No. 893,640

(Fig. 2).

In the -girder disclosed in Fig. l the web members are connected to the main tensile reinforcement indirectly by the coherent mass filling the central space between plates p (Fig. at) and by the transverse bolts placed inside the loops of the web bars. The web bars have a firm grip on the mass filling said space through the loops of the bars and the web stresses enter the main tensile reinforce.-

ment partly through the adherence or friction of the coherent mass on faces s of plates 79 (Fig. 4) and partly through the bolts. When the loops extend suiiiciently far into the main tensile reinforcement the web stresses may be transmitted to plates p without the help of the bolt rIhe connections ofthe web bars to the web posts or to the compression flange members must be governed by the stresses to be transmitted. In Fig. l the web bars F are simply7 extended between the webs of the upper built-up members and end post channels and terminate near the upper and end faces of the girdcr. In structures having no compression steel in the compression flange it is desirable to eX- tend at least a suflicient number ot web bars to points close to the compression face.

The internal distribution of the web stresses as set forth previously is, strictly speaking, only true for web bars covering' the whole thickness of the web, that is to say, intercepting all web compression stresses. In practice, however, 'it is generally necessary to give the web a thickness somewhat in excess of the total width of the bars in order to protect the metal against corrosion. It is obvious that in order to obtain the greatest benefit -trom the flat web bars the latter should cover as much as possible of the thickness of the web. If the width of the web bars is gradually decreased in a web of lined thickness, the uncovered part of the web thickness tends more and more to modify the web stress distribution; on the other hand, the bearing surfaces offered to the web compression stresses against the web bars decrease and these stresses therefore increase. It `is estimated, however, that structures ink which the web bars cover not less than five-tenths of the web thickness may with sufficient accuracy be figured for the distribution corresponding to wide bars if proper allowance is made for the actual width of the bars. Such structures possess over ordinary reinforced concrete structures the advantages imparted by a more correct analysis of the internal stresses. The girdershown in Figs. l, 2, 3 and et is provided with wide web bars each cov ring nearly the wholevthicli'ness of the web. This girder may be regarded as reinforced by a single set of web bars. Instead ci one single set of wide bars it may be of ad# vant-age to use two or several bars, the combined width of the bars of the narrow sets being equal to the width of the bars which should be used in a single wide set.

The girder shown in cross-section in Fig 11 of narrow bars have been used in suoli a man-v ner as to give a staggered arrangement of t-he bars. W hen two or several sets of narrow sets of narrowv web bars are used, the spacing of the bars for each set should be as close as if one single set of wide bars were used.

On Figs. 10 to 17, inclusive, the various construction features described previously have been embodied in structures other than lim simple girders on two supports. Fig. 10 is a view in side elevation of one half of a .ca-ntilever system extending over tive openings and resting on four pier supports. rIhe structure is symmetrical about the vertical center line m fit. Girder AI),l rests on two supports B and E, and is provided with two cantilever arn'is AB and ED, the first-named arm covering the entire end opening and the other arm a part of the center opening. Girder AD is made oftwo webbed parts Agli and MD and three struts 9E, ILE and E meeting on support E. The webbed parts have main reinforcements both in the tension flan ges and in the compression flanges with the exception of cantilever arm AB in which the compression flange reinforcement has been omitted. Both tension flange and compression flange reinforcements are composed of two channels c and a central plate p (Fig. 11) arranged so as to provide two spaces for the acconnnodation of the web members F which consist here, as already mentioned, of two setsof narrow flat web bars placed opposite each other. The shortindependent girder in the central opening, of which only one half DM is shown, has a main tensile reinforcement consisting of two flat bars p anda compression flange reinforcement made of two channels c (Fig. 14).

Flat bars p and channels c are separated suliiciently to receive the web members F which comprise a single set of wide bars. In order to provide, for this independent girder, a hinged support at D (Fig. 10), two web posts may be utilized at this point, one of the posts forming the end of the girder and the other the end of the cantilever arm ED. Tothese posts may be secured steel brackets 7c, s, separated by an expansion roller 0, through the intermediary of which the girderend may be supported by the cantilever end.

Each of the web posts at B', g, e' and D may consist of two channels and each of the struts gld and E may comprise two channels c and a central plate p 12). In strut tl the central plate is indicated as having been omitted (Fig. 13). Flange members, web posts and struts for this cantilever system, instead of being composed of comparatively light sections, as' shown, may be made of heavy built-up members if necessary.

rlhe web post-s at B, g and i (Fig. 10) serve the same purpose as the end posts of the girder of Fig. 1 in preventing the concentration of compression stresses in thel lower part of the web at these points, and the web posts at D distribute the steel bracket reactions uniformly into the web of the cantilever arm and the web of the short center girder.

The connections of the struts and web posts to the flange members may be effected by means of rivets or other appropriate fastening elements. ,r

rlfhe struts (Figs. 12 and 13) may be encased in concrete, which material may also be used in the webs and flanges of the entire cantilever system.

Jall flange members, web posts and struts may be connected transversely by bolts, and the web-reinforcing members may have looped connections with the reinforcing members of the tension flanges.

ln order not to complicate the drawing, the transverse bolts, loops ofthe web members and rivet connections at the ends of the '.ange members, web posts and struts'hare not been indicated in Fig. 10.

Fig. 15 is a view in side elevation of one half of an arch ribV with the ends fixed in abutment walls. rlhe structure is entirely symmetrical about the vertical axis m2, m2. The arch rib has a main reinforcement in both the intrados flange HG and in the extrados flange AC; the abutment wall has a main reinforcement near each end face GF and CE. Members E2G and GD are web posts whose purpose is to distribute gradually into the web the local compression stresses created at point G by the. elbows in the flange members; their functions are, therefore, similar to those of the web posts previously described, and, like the latter, are

most effective when they are connected to the web members. All flange members for the rib and abutments as well as the web posts consist each of two channels c connected by transverse bolts Z) and separated sufficiently to accommodate the web members F (Figs. 16 and 17). As in the case of the previous cantilever system,'heavy built-up members could be used instead of channels for the flange members and webl posts of this arch struct-ure if necessary. The web-reinforcing` members may consist of one single set of bars F (Figs. 15, 16 and 17) having looped connections with the reinforcing members of the tension flanges. The material used in the webs and flanges may be concrete. rIwo channels arranged in the same manner as for the flange members have been provided at the bottom F E of the abutment wall (Fig. 15). rlhe transverse bolts, the loops of the webreinforcing members and riveted connections at the points B2, G, F, E, D and C have not been shown on Fig. 15.

*What is claimed is 1. A reinforced concrete girder comprising a web portion extending throughout substantially its entire length and a flanged portion extending along` its zone of greatest tensile stress, a tensile reinforcing member of greater width than the thickness of said web portion embedded in and extending along said flanged portion, and web reinforcing meinbers spaced along saidgirder, from end to end each having a part anchored in said flanged portion and a part embedded in and extending across said web portion, said web reinforcing members comprising relatively thin bars of a width of not less than onehalf the thickness of the web portion of the .girder the greatest cross-sectional dimension of each bar being disposed in the direction of the width or thickness of the girder and, the distances between successive bars being not more than half'thedepth of the girder.

fr reinforced concrete girder comprising a web portion extending throughourl substantially its entire length and a vflanged portion extending `along its Zone of greatest tensile stress, a tensile reinforcing member of greater width than the thickness of said web portion embedded in and extending along said flanged portion and sets of spaced web reinforcing members in side-by-side arrangement, each ,having a part anchored in said flanged portion and a part embedded in and `ei-:tending across said web portion, said web reinforcing members comprising relatively thin bars, each having its greatest cross-sectional dimension disposed in the direction of the width or thickness of the girder, the combined width of the bars of the various sets being not less than one-half the width of the web portion of the girder and the distances between the successive bars of any set being not more than half the depth of the girder. y

3. A reinforced concrete girder having spaced main tensile reinforcing members embedded` therein and: extending in side-by-side relationalongits zone of greatest tensile stress, and additional reinforcing members embedded in and spaced along said girder,

sion4 of each bar being disposed iu the direction of the width or thickness of the girder.

t.- 'A reinforced concrete girder comprising a web portion extending substantially throughout its entire length, a flanged portiony along its Zone of greatest tensile stress, a flanged portion along its zone of greatest compressive stress, a tensile reinforcing member of greater width than the thickness of. said webl portion embedded in and extending along t-he flanged portion in the zone of greatest tensile stress, a compression reinforcingmember embedded in and extending along the flanged portion in the zone of greatest compressive stress, and web reinforcing members spaced along said girder, eachA having apart anchored to said tensile reinforcement and a part embedded in and extending across said webportionV towards said compression reinforcement, said web reinforcing members comprising relatively7 thin bars of a width ofnot less than one-half the thickness of the web portion of said girder, the greatest cross-sectional dimension of each bar being disposed inthe direction of the width or thickness of the girder.

5'. A reinforced concrete girder having spaced main tensile reinforcing members embedded therein and extending in side-by-side relation along its zone of greatest tensile stress, coupling elements spaced along said reinforcing members and connecting them ,through the intervening concrete, and addition al reinforcing members embeddedA in and spacedl along saidV girder, saidl additional reinforcing members having parts extending into the space between said: main reinforcing members and looped about. said coupling elements and parts extending crosswise of said girder from its zone of greatest tensile stress towards its zone of greatest compressive stress,

6. A reinforced concrete girder having spacedy main tensile reinforcing members embedded therein and extendingl in side-by-side relation along its zone of greatesttensile st-ress, coupling elements spaced' along said reinforcing members and connecting them through they intervening concrete, and additional reinforcing members embedded iny and spaced along said girder, each of said additional reinforcingmembers having an intermediate portion extending into the space between said main reinforcing members and looped' about a plurality of said coupling elements, and end portions extending crosswise of said girder fromits zoneof greatestI tensile stress towards its zonel of greatest compressive stress.

7. A reinforced concrete girder comprising a web portion and a flanged portion extending along its Zone of Ygreatest tensile stress, spaced main tensile reinforcing members embedded in and extending along said flanged portion., coupling elements spaced along said marin tensile reinforcing members and connecting them through the intervening' concrete, and web reinforcing members embedded in and spaced along said girder, said vweb reinforcing members having portions looped about said coupling element-s and parts extending acrosssaid web portion.

S. A reinforced concrete girder comprising a web portion and' a flanged portion extending along its zone of greatest tensileV stress, spaced main tensile reinforcing members embedded in and extending alongl said flanged portion, coupling elements spaced along said main tensile reinforcing members and connecting them through the intervening concrete, and web reinforcing members embedded in and spaced along said girder, each of said web reinforcing members comprising a thin flat bar having its intermediate portion looped about a plurality of said coupling elements and its end portions extended across said web portion, the width of said bar being not less than one-half the thickness of said web portion and disposed crosswise thereof and the distances between the various bar end portions extending across said web portion being not greater than one-half the depth of the girder. l

9. A reinforced concrete girder comprising a web portion and a flanged portion extending along its zone of great-est tensile stress, spaced main tensile reinforcing'members embeddedv in and extending along said hanged portion, coupling elements spaced along said main tensile reinforcing members and connecting them through the intervening concrete, and sets of web reinforcing members embedded in and spaced along said gird'er in. side-by-side arrangement, each of said webreinforcing members comprising a thin flat bar having its intermediate portion looped about a plurality of said coupling elements and its end' portions extended across said web portion, the combined' width of the bars of the various sets being. not less than one-half the width of said web portion and disposed crosswise thereof and the distances between the various end portions of the barsV of any set being not greater than one-half. the depth ofthe girder.

lil-3 llc 10. A reinforced concrete girder comprising a web portion extending substantially throughout its entire length, a flanged portion along its Zone of greatest tensile stress, a flanged portion along its zone of greatest compressive stress, a tensile reinforcing incmber of gres ltl than the thickness of said web portion embedded in and extending along the flanged portion in the zone of greatest tensile stress, a compression reinforcing' member embedded in and extending along the flanged portion in the zone of greatest compressive stress, and web reinforcing members spaced along said girder, each having a part anchored to said tensile reinforcement and a aart embedded in and extending across said web portion towards said compression reinforcement, some of the parts of said web reinforcing members being extended continuously from said tensile reinforcement to said compression reinforcement and some being extended only part way across said web portion.

11. A concrete girner having spaced main tensile reinforcing` members en'ibedded therein and extending in side-by-sine relation along its Zone of greatest tensile stress, coupling elements spaced along said reinforcing members and connecting them through the intervening concrete, reinforcing members embedded in said girder and extending upwardly therethrough from its points of support, and reinforcing members, embeddec. in said girder, having intermediate portionslooped about said coupling elements at points separated from said points of support and end portions extending obliquely across the adjacent parts of said girder and terminat-` ing adjacent said upwardly-extending reinforcing members at points separated from said points of support.

12. A girder, as dened by claim 11, of which each of the obliquely-disposed reinforcing members comprises a thin flat bar of a width not less than one-half the thickness of the enveloping part of the girder, said bar having greatest cross-sectional dimension disposed in the direction of the fidth or thickness of the girder.

13. A concrete girder having spaced main tensile reinforcing members embedded therein and extending in side-tj-side relation along its sone of greatest tensile stress, coupling' elements spaced along said reinforcing members and connecting them through the intervening concrete, reinforcing 'members embedded in said girder and extending upwardly therethrough from its points of support, and a plurality of spaced reinforcing members embedded in said girder yat varying distances from each of said points of support, each comprising a portion looped about one of said coupling elements anda portion extending obliquely across the adjacentpart of said girder and terminating adjacent one of said upWardly-extending reinforcing members.

1li. A girder, as delined by claim 13, of

which the obliquely-disposed reinforcing.

men bers comprise thin fiat bars, each of a width not less than one-half the thickness of the enveloping part of the girder, the distances between said bars being not greater than one-half the depth of the girder, and the greatest cross-sectional dimension of each being disposed in the direction of the width or thickness of the girder. i

15. A reinforced concrete girder having spaced main tensile reinforcing members en bedded therein and extending in side-by-side relation along' its zone of greatest tensile "ess, spaced main compression reinforcing members en'ibedded in and extending in sideby-side relation along its Zone of greatest compression stress, and additional reinforcing members embedded in and spaced along said girder, each having a. part extending cross said girder and anchored at its respective ends between said main tensile reinforcing members and said main compression reinforcing members, said additional reinforcing members comprising thin bars of a width not less than one-half the thickness of the enveloping portion ofthe girder, the greatest cross-sectional dimension of each bar being disposed in the direction of the width or thickness of the girder and the distances between successive bars being not greater than one-half the depth of the girder.

1G. A reinforced concrete girder having spaced main tensile reinforcing members embedded therein and extending in side-byside relation along its Zone of greatest tensile stress, spaced reinforcing members embedded therein and extending upwardly therethrough in side-by-side relation from its points of support, and additional reinforcing members embedded in said girder, each having a part extending obliquely across the part of said girder adjacent one of its points of support and anchored at its respective ends between said main tensile reinforcing members and said upwardly extending reinforcing members at points separated from said points of support.

17. A girder, as dei'ined by claim 16, of which the obliquely-disposed reinforcing members comprise thin flat bars of a width not less than one-half the thickness of the enveloping part of the girder, the distances between successive bars being not greater than one-half the depth of the girder, and the greatest cross-sectional dimension of each bar being disposed in the nirection of the width or thickness of the girder.

LOUISE MOCCETTI, Ado/rmzbtmtrd of the Estate of Ernest Lr'occetz', Deceased.

Images