US1581505A - Reenforcing fabric for cementitious slabs - Google Patents

Description

April 20 1926. 1,581,505

, E. L. BENEDICT ET AL REENFORCING FABRIC FOR CEMENTITIOUS SLABS Filed May 29, 1924 4 Sheets-Sheet 1 FIG. 3.

' INVENTDRS E chm-rd L'Bemwtict a Robert L. Glose L. BENEDICT ET AL REENFORQINGFABRIC FOR CEMENTITIOUS' SLABS A ril 20 1926. I 1,581,505

Filed May 1924 I 4 Sheets-Sheet 2 X/KL April 20, 1926. 1,581,505

- E. L. BENEDICT ET AL REENFORCING FABRI C FOR CEMENTITIOUS SLABS Filed May 29, 1.924 4 sheets- B FIG J5 /c 4 ad x W J 4C Flt-7.9. FIG.ID.

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Patented 29, 1926..

UNITED STATES PATENT EDWARD L. BENEDICT AND ROBERT GLOSE, OF IIT'ISBURGH, PENNSYLVANIA, v

BEENFOROING' FABRIC FOR CEMEN'IITIOUS SLABS.

Application fi ed May 29, 1924. Seria1-No.,716,693.

other generally. similar structures. I

.One object of the invention is to-provide a fabric for reeforcing a cementitious monolith against variously directed stresses, which requires little or no assembling of the elements thereof in laying the fabric.

Another object of the invention is to provide reenforcing fabric in which the various elements of the fabric fully per'forma thefunctions of supporting and mutually spacing: the other elements thereof, so that the fabric may be laid entire without depend ing uponthe material in which it is to be embedded for support or spacing oftheiele- A further object of the invention is to provide such rigidity in the support of the main reenforcing elements of the fabric,

that such elements are held rigidly against any movement during pouring of the embedding mater al which m ght-create a space ad acent such reenforcmg elements; and'to so anchor the' main reenforcing elements that vibration of the same in a slab of cementitious material is entirely prevented.

A still further object of the inventionis to provide a reenforcing fabric of the nature indicated, which is susceptible of ready adaptation to various uses, and conditions of use, without radical change in its general structure or sacrifice of'the advantages noted above. s

In the accompanying drawingsFigure 1 is'a. plan view of one fornrof reent'orcing fabric embodying the principles of the present invention; Figure 2 is a' side elevation of the same; Figure 3 is a front elevation of the same; Figure 4. is an isometric view of the same; Figure 5 is a -plan view of a' special modified form of the fabric, showing such fabriowith the omission of one reenforcing element thereof; Figure 6is aside elevation this mod fied form of the fabrie;"Figiire 'l' is a plan view te'saine modified fabric, showing the same 'as laid prior to the addition of the cementitious material 111 whlch'lt is to be embedded, and

showing the reenforcing element whichis omitted from Figures 5 and 6; Figure Sis a side elevation of the structure illustrated in Figure 7; Figure 9 is an. end elevation of another modified form of the reenforcing fabric; Figure 10 is aside elevation of, the same; Figure 11 is a cross sectional view through a roadway, showingthe-reenforc ing fabric-of Figures 1; to Ainelusive embedded in the cementitious material of the roadway; Figure 12 is a cross sectional view through a roadway, illustrating one manner of adapting the form of fabric shown inFigures'l to 4: inclusive to a roadway having a subgrade inclined. toward the sides thereof;Figure 13, isa cross sectional view of a roadway illustrating another manner ofadapting this form. oftherfabric to an inclined suhgra-de; Figure 14 is a-fragmentary cross sectional view through a roadway, illustrating the adaptation of the structure shown in Figure 9 to an. inclined subgrade; Figure 15 is an end. elevation. of a modified form of fabric, which corresponds generally to the form shown in Figures 1 to 4: of the drawings, but showing a modified positioning ofasingle mainreenforcing element; and Figure lti shows a further modification in the structure of Figures 1 to 4, which embodies an additional main reenforcing element. I f

In the simplest formof the device, as show in Figures 1 to at inclusive-of the drawings, the fabric comprises strand members or elements 1, which may be rods-"bars or heavy wires; and stay members or elements 2, which extend transversely of the strand elements, and which are preferably wires, but maybe bars or rods if so desired. The. stay elements Qare welded or tied to the strand elements 1 in any suitable manner. As shown, the stay elements 2 are off-set from the horizontal plane of the strand elements 1 to: form .loops 3, havingextremities 4 lying ina common plane parallel to the horizontal plane of the strand elements, or upper horizontal plane of the fabric.

;-According to one method ofmanufacturing the fabric, the-stay elements-2 are originally disposed-in substantially-the same horizontal plane as, and at right" angles to, the strand elements 1,- and areivelded or otherwise suitably secured thei.eto;}T-hese stay elements are then offset a uniform vertical distance from their original horizontal plane, which is the upper horizontal plane of the fabric. As the offsetting of these loops is uniform throughout the fabric, the, uni form spacing of the strand, or main reenforcing, elements is not affected by the formation of the loops in the stay elements.

In order to secure increased rigidity of the fabric, the loops 3 are offset at an angle to the vertical plane of each of the strand elements. As shown, adjacent loops of the same stay members or elements are offset at opposite angles to such plane to provide equally but oppositely inclined loops with their extremities 4 lying in a common plane parallel to the horizontal plane of the strand elements. The angular disposition of the loops 3 may be effected simultaneously with the offsetting of the stay wires to form the loops; and is effected y exertingforces to distort the stay wires both longitudinally of and at right angles to the horizontal plane of the strand elements, thus producing the inclined loops 8 as the resultant such forces. It will be noted that all the extremities 4 of each row 5, that is all the loops lying between the same two strand elements, are inclined in the same direction and that the bends of any row or rows adjacentto a designated row extend at an opposite angle to those of the designated row. This effect of this staggered arrangement of the loops is to secure the maximum support an forded by a triangular base.

The modified form of fabric shown in Figures 7 and 8 inclusive of the drawings, combines the principles and advantages of the form described above with those of a transversely extending and relatively heavy reinforcing element, which is supported between the horizontal plane of the strand elements 1 and the horizontal plane of the extremities 4 of the loops 3.

The preliminary steps in the manufacture of this modified form of fabric are identical with those employed in manufacturing the form of fabric previously described. After such steps have been performed, however, alternate strand elements are pulled longitudinally in opposite directions to distort the loops 3 This distortion of the loops causes each loop to comprise a leg 6, and a leg 7 inclined at a lesser angle to the vertical plane of its strand element than the leg 6.

It will be observed that the crossing of the legs 6 throughout the same stay element provides a seat for an additional horizontal reenforcing element 8, which may be a rod, bar, or heavy wire; and that this transversely extending reenforcing' element is supported between the horizontal plane of the strand elements and the horizontal plane of the extremities P of the loops of the stay elements.

With the arrangement of this modification, substantially the same effect is obtained whether the strand elements of the fabric be laid longitudinally or transversely of the *oadway. ditional reenforcing elements give a reenforcement extending at right angles to that of the strand elements.

The modification illustrated in Figures 9 and 10 of the drawings comprises the combination of two complete fabric members A and B. Of these the member A is identical with the form of fabric shown in Figures 1 to 4 inclusive; and comprises the stay members 2 with loops 3 and extremities r the stay members being secured to strand, or main reenforcing, elements 1. The member B is also similar, but is made with the loops 3 of the stay elements offset a lesser distance from the horizontal plane 4 of the strand elements 1 of the fabric member.

In assembling the members for laying of the fabric in constructing a roadway, the fabric member B is inverted and placed over the fabric member A in such manner that the inner side of the extremities a of fabric member B rest on the strand elements 1 of the fabric member A. The loops 3 thus extend downwardly for a portion of the depth of the bends 3, and support the strand elements 1 at points above the extremities 4 of the bends 3.

This modification provides additional reenforcing elements, which extend parallel to the strand elements of the main fabric member, but which are spaced vertically from the horizontal plane of the extremities of the loops formed in the stay elements of the main fabric member, that is, they are spaced vertically from both the upper and lower horizontal planes of the completed fabric.

Figure 11 of the drawings shows the simplest form of the reenforcing fabric, that illustrated in Figures 1 to a inclusive, embedded in a concrete roadway, and'extending completely across the same. This figure may also be taken as generally illustrative of one disposition of any of the modified forms of the fabric in a roadway.

In present day concrete road building it is considered good practice to have the road slab thicker along the sides of the read than at its center. As the road surface is generally crowned, or higher along the center of the road, this effect is secured by inclining the subgrade of the road downwardly toward both'sides of the road.

Figure 12 of the drawings illustrates one manner of adopting the form of the device shown in Figures 1 to inclusive to accommodate for this inclination, while maintaining the strand, or main reenforcing, elements substantially parallel to the surface of the This is the case because the adroadway; In this arrangement the fabric is laid with the strand elementsl disposed transversely of the roadway. The inclination of the suhgrade is here accommodated for by varying the angular dispositionof the loops 3. As shown, the loops adjacentthe sides of the road arespread to the least extent. Successive loops inwardly from both sides of the'ro'ad are spreadtoa successively greater ex ent, sothat the lower planeof the fabric, formed by "the extremities 4 of the loops, is inclined to the perpendicular adegree substantially equal to the inclination of the sul'igradeof" the roadway:

Figure 13 illustratesanother manner 'of adapting the same-initial form of fabricdo the same condition'of use. In such arrangement the strand,'or main reenforcing, ele-.

to the inclination of the subgrade of the roadway.

Starting with-a 'fabric'lyingin a single horizontal plane, and with the strand elementsspaced mutually at equal-distances, the unequal offsetting of the-loops will produce a grouping; or i narrower spacingof the-strand elements along the sides: of the fabric. If desired'this effect may be avoided by spacing the strand elements initially an unequal distance, butt-he grouping as shown is preferable inroads, or portions thereof which are subjectedto certain traffic conditions' I The fabric inayalso be arranged to-accommodate for an inclination'of the subgrade, whilehaving the' strand' or main reenforcing, elements extend longitudinally of the roadway. This is effected" by progressively increasing the horizontal extension or distortion of successive loops 3 of' each of he stay wires 2 transverselyof the fabric.

Obviously such arrangen'ienidoes'not alter the mutual spacing of the strand, or main reenforci'ng, elements.

Both ways of accommodating for an inclined subgrade may be readily effected during the manufacture of the fabric, and both illustrate the inherent adaptability of this fundamental form to various conditions of use. It should be observed thatthis adaptation does not sacrifice the advantage of the tr angular support given by the-inclination of the offset loops of the fabric.

Figure 15 of the drawings illustrates a modified form of the fabric in which the strand, or main reenforcing, elements 1 are welded tov the legs or the loops 3 formed in the stay elements at a point below the upper extremities 9formed by the offsettingof the stay elements. This provides a vertical spacing of the main reenforeing elements partway hetweenthe upper and lower hori- ZOl'ltdl planes of the fabric, and has the advantage, with certain classes of roadway, that the main reenforcing element serve'to reenfor'ce the slab partway of its depth. 7

Figure 16 of the drawings illustrates a modified" form ofthe fabric in which two strand elements 1 are supported close together on the same leg of aloopof the'stay elements". As shown, both of these strand elements are relatively'close to the upper extremities fi 'forined in offsetting the loops. This particular modification permits the use of lighter strand elements, while increasing the total cross sectional-area and bonding area of the strand elements.

Both these modifications are' in'o ther respects identical with thefundamentah form shown in Figures 1 to l of the drawings, and'may be assumedto have the loops of the stay elements inclined to give the same triangular support'.

It is of great importance that the structure of thefabric is such that it is self-supporting and self-spacing with respectto its various elements, so that the cementitious material to form the slab in which-the reenforcement isem'bedded may simply be poured over the fabric whenthe latterhas been placed in position. lVi-th materials of which this is not true, it is necessary; in order to space the reenforce-ment inthe slab, that a layer of' the cementitious material be first poured, 5 the 'reenforcement laid thereon, and the pouring operation then completed; This operation involves a duplication of labor, and frequently requires the mixture of a fresh batch of the cementit-ious material.

The rigidity of the fabric structure is also of great importance. Any slight shifting of the fabric, due to inequality -of weight distribution thereon, during or'immediately after pouring of the cementitious material, would result in the formation of small spaces in the body of the slab. Such spaces would permit vibration of the fabric, with increasing pulverization of the enclosing material and relatively rapid disintegration of the slab.

Any possibility of such a condition is avoided by the inclination and staggering of the loops of the stay elements .of the fabric, which maintain the fabric as a Whole al' solutely--stati0nary through all ordinary contingencies incident to laying and pouring. It may be noted in this connection that each stay element constitutes a triangular supporting element extending transversely of the strand elements. The form of the loops also results in a firm anchoringof the strand, or main reenforcing, elements in the slab, so that no vibration and play is initially permitted to produce an increasing cavity in and pulverization of the embedding material.

The form and arrangement of the loops of the stay wires also serve to securely anchor the main rcenforcing elements in a finished slab against vibration under the impacts delivered by traliic passing over the slab. This avoids any possibility of the wearing of cavities in the cementitious mateiial of the slab by vibration of the men forcing members therein.

lt is also to be noted that the shear stresses in a concrete block in which this fabric is embedded are crossed by the stay elements because of their angular position and staggered arrangement.

As numerousmodifications in the form and arrangement of the elements of the fabric, other than those illustrated and scribed herein, may be made without departing from the principles of the present invention, the scope of the invention is to be restricted only by the limitations contained in the claims appended hereto.

What we claim is:

1. A. reenforcing fabric for use with cementitious materials comprising a plurality of strand elements disposed in the same horizontal plane, and transverse stay elements interconnecting said strand elements; each of the stay elements having loops offset at an angle to the horizontal plane of the strand elements, and alternate loops of each stay element being offset at opposite angles, to provide distributed supporting means for the entire fabric during the pouring of a concrete slab and to secure a maximum distribution of metal throughout the body of such slab.

2. A reenforcing fabric for use with cementitious materials comprising a plurality of strand elements disposed in the same horizontal plane, and transverse stay elements interconnecting the strand elements and having loops offset from the horizontal. plane of the strand elements at surh angles that each stay element constitutes a transverse triangular support for the strand elements of the fabric.

3, A concrete roadway having a reenforo ing fabric embedded therein, said fabriccomprising a plurality of reenforcing strand elements extending longitudinally of the roadway and elements of greater flexibility secured to the strand elements and extending transversely of the strand elements and the roadway, each ofsaid transverse elements being formed with loops offset at an angle to the surface of the roadway and the transverse elements being so arranged that the loops of the same element have their horizontal extension in opposite directions in alternate intervals between strand elements.

l A concrete roadway having a reenforcing fabric embedded therein; said fabric comprising strand elements extending longitudinally of the roadway, and stay elements secured to the strand elements and extending transversely of the strand elements and the roadway; thestay elements having loops offset at an angle to the surface of the roadway, and successive loops of each stay element being of graduated vertical extent transversely of the roadway to accommodate the fabric to an inclined subgrade in the roadway.

5. A concrete roadway having a reenforcing fabric embedded therein; said fabric comprising strand elements extending longitudinally of the roadway, and stay elements secured to the strand elements and extending transversely of the strand elements and of the roadway; the stay elements having loops offset at an angle to the surface of the roadway and so arranged that the loops of the same element have their horizontal extension in opposite directions in alternate intervals between strand elements, and successive loops of each stay element being of graduated vertical extent transversely of the roadway to accommodate the fabric to an inclined subgrade in the roadway.

6. A reenforcing fabric for use with ce mentitious materials comprising a plurality of trand elements disposed in the same horizontal plane, and transverse stay elements interconnecting the strand elements, said stay elements being formed with loops offset, from the horizontal plane of the strand elements and ext-ending longitudinally ofthe strand elements, the loops in adjacent intervals between strand elements extending in opposite longitudinal directions.

in testimony whereof, we hereunto set our hands.

EDl/VARD L. BENEDICT. ROBERT L. GLOSE.

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