US2208000A - Joint for concrete slabs - Google Patents

Description

July 16, 1940. E, H, GEYER 2,208,000

JOINT .FOR CONCRETE SLABS Filed Sept. 50, 1937 2 Sheets-Sheet l July 16, 1940. E. H. GEYER JOINT FOR CONCRETEl sLABs 2 Sheets-Sheet 2 Filed sept. 3o, 1957 @MMA @ya Patented July 16, 1940' JOINT FOR CONCRETE SLABS Ernest VHQG'eyer, Chicago, Ill., assigner of onef half to Henry A. Taubensee, Chicago, Ill.

Application september 3o, 1937, serial No. 166,501 '11' claims. (ol. 9418) The present invention relates generally to joints for concrete slabs More particularly the invention relates to that type of'joint which is adapted for use between a'pair of adjoining road- 5 way-forming slabs on a subgrade, operates as a load transfer unit and at the same time permits the slabs to move to .and from one another in response to expansion and contraction, and comprises (1) an elongated hollow sheet metal structure "which is adapted to fit between the slabs and to contract and expand in connection with l and dowel rods in the sleeves and have the central portions thereof extending; through the hollow structure andtheir end portions projecting from .opposite sides of the structure'and adapted for embedment 'in the slabs.,y

One object of the invention is to provide a joint of this type which inl addition to the elongated hollow sheet metal structure and the lo'ad transfer elements comprises a novel drain for conducting or guiding to the sides of the subgrade any water which accumulates under the joint; ,i

Another object of the invention is to-provide a joint of the last mentioned character in which the drain is disposed beneath and coextensve with the hollow structure andl has a central open top channel in which the'bottom portion of the hollow structure fits and also yhas a pair of laterally spaced side legs which have. out-turned flanges along the bottom margins thereof for supsubgrade and preventing them 'from tilting laterally during pouring .of the concrete in connection with the formation of the slabs. v

Still another object of the invention is to provide a joint of the type and character under consideration in which the ends of the drain along the bottom portion of the hollow structure have wedge shaped troughs which are arranged or po porting the dra-in and hollow structure on the.

the outer or large ends of the troughs against 'the inflow of concrete and are further adapted after formation of the slabs', that is, setting of the concrete and removal of the roadway side forms to be bent outwards into a position where- 5 in lthey serve as a centering medium fory the inner ends of the drain pipes at the sides of the subgra-de.V A Y Av still further object of the invention is to pro'- Vide a joint of the aforementioned type which 10 includes novel means for closing the ends .of the elongated hollow structure.

In addition the invention contemplates as one of its objects the provision `of a concrete slab joint which is generally of new and improved construc- 15 tion, may be manufactured at a comparatively low and reasonable cost, and is not only more .efficientthan previously designed joints for the same purpose and of the' same general character but also is an improvement upon and has cer- 20 tain advantages over the joint which i's shown in and forms the subject matter of United States Letters Patent No. 2,095,060, granted to me October 5, 1937.

Other objects of the invention and the various 25 y clusion thereof.

In the drawings which accompanyv and vform a part of this specication or disclosure and in which like numerals of reference denote corre- 35 sponding parts throughout the several views:

Figure 1 is a vertical transverse sectional view of a join-t embodying the invention;

Figure 2 is a View lpartly in side elevation and partly in longitudinal 'section showing the joint in place on the subgrade'with the ends thereof in abutment with the roadway side forms;

Figure 3 is a similar viewshowing the joint after removal of they side forms from the ends' thereof and after setting of the concrete and application of the drain pipes to the tongues on the wedge-shaped troughs at the ends of the drain;

Figure 4 is a perspective of one of the composition type compressible plugs which constitute part of the means for closing the ends of the hollow structure against inow of concrete during formation of the slabs at the sides of the structure;

Figure 5 is a perspective .of .one of the fiange equipped sheet metal end closures which constitute another pa-rt of the closing means for the ends of the hollow structure;

Figure 6 is a perspective of one of the U-shaped composition type compressible plugs which serve to close the ends of the drain against the inow of concrete during the concrete pouring operav tion;

low structure showing such end without itscom? pressible type composition plug and flange equipped sheet metal end closure and illustrating the manner in which the tongues on the wedgeshaped troughs at the ends of the drain are adapted to be bent outwards into a position wherein they serve as a centering medium for the inner ends of the drain pipes at the sides of the subgrade; and

Figure 9,'is another perspective view of such one end of the hollow structure showing the compressible plug and sheet metal end closure for such end in their operative position Y and showing the manner in which the U-sl'iaped'com'- pressible plugs serve to close the ends of the drain and also the manner in which the tongues at the outer or large ends of the wedge shaped troughs operate during pouring of the concrete at the sides of the structure to close the ends of the trough against inflow of concrete.

The joint which is shown-in the drawings constitutes the preferred embodiment of the invention. It is shown in connection with a pair of roadway forming concrete slabs S on a subgrade SG and comprises an elongated hollow structure I 0 and a set or series of laterally spaced load transfer elements II. The slabs S with which the improved joint is shown are positioned in adjoining relation, and the subgrade SG on which the slabs are disposed has beveled or downwardly inclined side portions, as shown in Figures 2 and 3. The slabs S are formed by pouring concrete at thesides of the joint and between side 4forms F at the sides of the subgrade, as well understood in the art.

The hollow structure III is yadapted to ft between the opposed faces of the slabs and serves as hereinafter described, as an elastic seal between the two slabs whereby the passage of dirt, water and other foreign matter between the slabs is precluded. It is of uniform height from one end thereof to the other and consists of a onepiece U-shaped sheet metal lower member I2 and a one-piece inverted U-shaped sheet metal upper member I3. The height of the hollow structure IIJ corresponds substantially to the height of the slabs S and the length is slightly less than the width of the slabs, as shown in Figures 2 and 3. The lower member I2 consists of a pair of later-` ally spaced side walls I4, a bottom wall I5, and a pair of outwardly extending top flanges I6. The side walls I4 are held by the .bottom wall I5 in laterally spaced relation. They embody in the upper portions thereof equidistantly spaced pairs of aligned holes II and are adapted as shown in'Figure 1 to abut directly against the opposed faces of the slabs S. The bottom wall I5 is V- shaped and straight and permits the side walls I4 to. move toward and'away from one another in response to expansion and contraction of the faces of the slabs.

slabs. The to-p flanges I6 of the lower member I2 are the same in length as the side walls I4 and I 2 and is the same in length as the latter. lIt

serves as a cap or top closure for the lower'member of the hollow structure and embodies integral outwardly extending bottom flanges IS.

The latter extend upwards, outwards, and theny downwardly and conform to and rest on the top flanges I6' of the U-shaped lower member I2. Rivets I9 extend through the outwardly extend: ing portions of the flanges I6 and I8 and serve to hold the upper and lower members in connected relation. The bottom flanges I8 of the upper member form troughs to prevent seepage of water around the top flanges I6 and downwards across the side walls I4' of the lower member I2, and are adapted for interlocking embedment in the slabs S and to cause the side walls of the upper member I3 o-f the hollow structure to contract and expand in harmony with-exrpansion and contraction of the slabs. VThe ltop wall of the upper ,member I3 is .adapted to support a plastic filling 20 so that the top face thereof is substantially of the slabs S.

The load transfer elements II are' adapted to v transfer load from one slab to the otherv and consists of one-piece sheet metal sleeves 2l and metallic dowel'rods 22 in the sleeves. The central portons'of the sleeves extend lthrough the pairs of aligned holes I1 in the upper portions of the side walls I4 of the U-shaped lower member I2 of the ho-llowstructu'refand are supported or carried by pairsv of coacting spreader plates 23. The' end portions of the sleeves project from adapted for embedment in and to become bonded to the slabs S. The central portions of the sleeves are weakened by way of slots 24 so that v they will readily expander distend or rupture .and thus permit the end portions -to move to and from one ano-ther in response to expansion or contraction of Ithe slabs. The outer extremities of the sleeves are closed'by means of sheet 'metal caps 25 which are suitably secured in place to prevent concrete from flowing into the sleeves during pouring of the slabs. 'The slots 24 arelocated within the hollow structure and hence are protected against concrete passing therethrough into the sleeves. Pairs of coacting spreader plates 23 are disposed in the hollow structure andare so arranged and formed that they urge the sides of the structure outwards into Contact or engagement Withthe opposed They correspondin number to the sleeves of the load transfer members and have integral out-turned annular bearing forming flanges 26 which extend through the holes I'I in the side walls I4 of the member I2 and nt snugly around the central portions ofthe sleeves. The dowel rods 22 are slightly shorter than the sleeves and are greased or otherwise lubricated so that they slide relatively to the sleeves and hence permit of load vtransfer from one slab to thev'other while at the same timel theyjpermitthe slabs to 'expand and contract.

ush with the top faces opposite sides of the hollow structure I and are l Y In addition to they elongated 'hollow structure IIl and the sleeve and dowel rodtype load transfer elements I I, the joint comprises an elongated sheet metal drain 21 and apair of sheet vmetal Wedge-shaped troughs 28, and in addition` end closing means 29 for the structure I0.

The drain 21 underlies and is'y coextensive with the V-shaped bottom wall I5 of the'lower member I4 of the hollow structure Ill. It is of M- shaped cross-section and consistsof a pair of laterally spaced side legs 30 and a V-shaped central leg 3|. The leg 3| corresponds in height to the side legs 30 of the drain and defines a central open top channel 32 in which Lthe V- shaped bottom wall I5 of the lower member I2 of the hollow structure fits snugly. The V-shaped central leg 3| and the wall I5 are welded or riveted together in order to hold the hollow structure in connected relationv with the drain. 'Ihe side legs 30 of the drainare formed integrally with and depend from the upper side margins of the leg 3| and dei-lne with said side leg a pair of downwardly facing channels 33 at opposite sides of the central channel 32. These channels 33 run from one en d of the hollow structure to the other and serve to guide or conduct to the sides of the 'subgrade SG any water which accumulates under the joint or the adjacent portions of the slabs S. The ends of the channels are plugged against the inflow of concrete during pouring of the slabs S by way of a pair of U-shaped compressible type composition plugs 34. These plugs project voutwardly from the ends of the drain 21 and the inner ends thereof are wedged or jammed within the inner ends of the channels 33 so that they are lxedly secured in place. The lower margins of Ithe laterally spaced side legs 30 of the drain embody integral out-turned flanges 35` which serve to reinforce the drain against iiexing sidewise. The central portions of the out-turned flanges 35 are adapted to rest on the crown or central portion of the subgrade SG, as shown in FiguresZ and 3, and serve not only to support the drain and hollow structure on the subgrade but also to prevent them from tilting laterally during pouring of the concrete in connection with the formation of the slabs S. By reason of the fact that the drain 21 extends from one end of the hollow structure I0 to the other the structure is eiectively reinforced andhas in effect a bottom wall of double thickness.

Ihe wedge-shaped troughs 28 underlie the end portions of the drain 21 and assist such portions in draining to the sidesfoffthe subgrade SG the water accumulating or collecting under the joint. They are U-shaped in cross-section and consist of flat bottom walls .36 and triangular sides 31 face outwards.

and are arranged so that the large ends thereof The side walls 31 are' spaced apart a distance corresponding to the `distance between the side legs 30 of the drain 21 and have integral out-turned top flanges 38 which underlie and are .welded or riveted tothe flanges 35 along the bottom margins of the side legs ofthe the troughs constitute partitions whereby concrete at oneside of the hollowstructure is yprevented fror'n flowing from one side of the hollow vstructure to the other during pouring of the slabs S. The outer or large ends of the troughs project beyond the ends of the hollow structure and' drain, as shown in the drawings, and are adapted to abut against the side forms F during pouring of the concrete for the slabs. ends of the bottom wallsv 36 of thetroughs join the inner ends of the out-turned flanges 38 with the result that there is substantially 'no space between the contiguous portions of the drain and the subjacent portions of the subgrade. outer ends of the bottom walls 36 of the troughs are extended to form integral tongues 39. These tongues are adapted to extend upwards 'and close the outer or large ends of the troughs during pouring of the concrete (see Figures 2 and 9) and 'are further adapted after formation of the slabs S and removal of the side forms F of the subgrade SG to be bent outwards and downwards into a position wherein they are'substantially coplanar with the bottom walls 36 of the troughs The innerl The and form a centering medium for the inner ends of drain pipes P at the sides of the subgrade.

'I'he length of the tongues 3S corresponds to the height of the large ends of the side walls 31 o1' the troughs and hence the tongues effectively close the outer ends of the troughs and prevent inflow of concrete during pouring of the concrete. When the tongues are bent upwards into theirtrough closing positionv t'he upper ends thereof underlie the outer ends of the U-shaped plugs 34 at the ends of the drain 21. The tongues 39 are adapted to fit within the inner ends of the drain pipes P, as shown in Figure 3, and serve to direct or conduct water from the troughs 28 to the pipes.

The end closing means 29 for the hollow structure I0 serves to prevent the concrete from flowing into the lends of the structure during pouring' of the slabs S and consists of a pair of sheet' metal end closures 40 and a pair ofr composition type compressible plugs 4|. The end lclosures 40 are U-shaped, as shown in Figure 5, and consist of a pair of laterally spaced side walls 42 and V-shaped inner end walls 43. They iit within the ends of the hollow structure l0, as shown in Figure`9, and are arranged or positioned so that the outer or free edges of the side walls thereof are flush with the end edges of the structure. The V-shaped inner end'walls ,41| of the endI closures are placed under compression when lthe end closures are shifted into place with the result that they urge the side walls 42 outwards into contact with the sides of the hollow structure I0 and assist `the spreader plates 23 in causing said sides of the structures to move outwards in harmony with the opposedfaces of the slabs S. The side walls of the end closures are provided along the outer margins'thereofwith integral out-turned anges 44. These flanges extend generally at right angles to the sides of the hollow structure and are'adapted for embedment in the slabs S. They extend'from the central portions of the outer side margins of the side walls 42 to the bottom edges of said side walls and are of channel shaped cross-section so that they become interlocked `with the slabs S after hardening of the latter and hence `cause the side walls 42 of the end closures t'o move inwards and outwards in response to expansion and contraction of the slabs. As shown in Figure 9 of the drawings, the flanges 44 are disposed beneath the out-'turned top ilanges I6 along the upper margins of the -side walls .I4 of the `U,-

shaped lower member l2 of the hollowstructure I0. The plugs 4I correspond in cross-sectionto the' interior of the hollow structure Il) and assist the end closures 4U of the closing means 29Y in preventing inflow of concrete with respect to the hollow structure. They are longitudinally aligned with thehollow structure and are adapted readily vtocorn-press in response to expansion of the slabs S. A*The inner portions of the-plugs 4l lit between the side `walls 42 of the end closures 40 and form a substantially elastic seal for the ends of the hollow structure. The outer portions of the plugs 4I overlie the U-shaped plugsl 34 and the outwardly projecting large ends of the troughs 28 serve to close the spaces between the ends of the hollow structure l0 and the side forms F at the sides of the subgrade SG during pouring of the concrete for the slabs S. The outer lower corners of the plugs 4l t within the U-shaped plugs 3ft,- as shownin Figure 9. By employing the composition type compressible plugs 4l the ends vof the hollow structure I0 are effectively sealed, and by employing the sheet metal iiange equipped end closures 4U the end portions of the sides of the hollowstructure are caused to move inwards and outwards in response to expansion and contraction of 'the slabs S.

In installingy or applying the joint the hollow structure I is first placed transversely across the subgrade SG and arranged so that the central portions of the out-turned flanges 35 of the drain 2l rest on the crown or central portion of the subgrade. After so positioning the hollow structure the load transfer elements Il are assembled with respect to the hollow structure by inserting the sleeves 2l with the dowel yrods therein through the bearing forming flanges 26 of the spreader plates 23. Thereafter the ends of the hollow structure are sealed by driving or hammering the sheet metal end closures 40 into place and inserting the inner portions ofthe plugs 4I into the end closures. After insertion of the plugs lll in the end closures GG the U-shaped plugs 34 are inserted into the ends of the drain 2l and the tongues '39 are bent upwards so as to close the outer or large ends of the troughs 28. Thereafter the roadway side forms F are placed in abutment with the tongues 39 and the outer end faces of the plugs 4l, as shown in Figure 2, and concrete is poured into the spaces at opposite sides of the hollow structure and between the forms F. Upon the setting or hardening of the concrete the resultant V-shaped slabs, as shown in Figure 1, abut against the sides of the hollow structure and have embedded therein the top flanges I6 of the U-shaped lower member I2 of the hollow structure and the bottom flanges i8 of the inverted U-shaped cap or upper member I3. In addition the slabs have embedded therein the end portions of the sleeves 2l of the load transfer elements and the out-turned channel type flanges 44 of the end closures 0.0. After formation of the slabs S that is,v hardening or setting of the concrete, the side forms F are removed and the tongues 39 at the outer or large ends of the trough 28 are swung outwards and downwards. Thereafter the drain pipes P are placed on the sides of the subgrade SG in alignment with the tongues and moved inwardly until the inner ends thereof extend around such tongues. At the conclusion of the pipe laying operation the portions of the roadway at the sides of the slabs 'S are lled in, as shown in Figure 3. Whenthe joint is in its assembled position with respect to the slabs S the dowel rods `22, which are slidably mounted in the sleeves 2|, transmit load from one slab tothe ,channels 33 in the drain 27 to the troughs 28 and l from the troughs outwards to the drain pipes P at the sides of the subgrade SG. c

vThe herein described joint eiciently and eff-i `15` fectively fulfills its intended purpose and not only is extremely durable and capable of long life but also may be manufactured at a` low and reasonable cost. It may be readily assembled at the place of use and contemplates a quick and ready drainage of any -water accumulating under Vthe central portion thereof.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims without departing from the spirit and scope of the invention. n

Having thuskdescribed the invention, what I claim as new and desire to secure by Letters Patent is:

1. A joint for alpair of `adjoining roadwayforming concrete slabs on a subgrade, comprising in combination an elongated compressible structure adapted to fit between the opposed faces of the slabs and form a seal therebetween, and a separately formed coeXtensive sheet metal drain of truly IVI-shaped cross-section positioned longitudinally of and under the structure and adapted to overlie and rest upon the subgrade and. having the central leg thereof defining an open top channel in which the bottom of the lstructure lits snugly and its side legs defining with the central leg a pair of downwardly facing channels at the sides of the open top channel and in communication with the subjacent portion of the subgrade for permitting any water accumulating under the joint to drain to the sides of the subgrade.

2. A joint for a pair of adjoining roadwayforming concrete slabs on a subgrade, comprising in combination anV elongated hollow structure adapted to fit between the opposed faces of the slabs and form a seal therebetween and em-v leg thereof defining an open top V-shaped channel corresponding in shape and size to the V- shaped bottom of the hollow structure and; in which said bottom lits snugly and is secured and having its side legs dening with the central legl a pair of downwardly facing channels at the sides of the open top channel and in communication with the subjacent portion of the subgrade for permitting any water accumulating under the joint to drain to the sides of the subgrade and provided along the bottom margins thereof with integral out-turned flanges for engaging the subgrade and holding the drain and hollow structure against tilting during pouring of the concrete for the slabs.

- 3. A'jon't for a pair of 'roadway-forming concrete slabs on a subgrade with beveled sides, comprising in combination a straight elongated hollow structure of substantially uniform' height from end to end and adaptedto fit betweenthe opposed faces of the slabs and form a seal there'- between, a pair of wedge-shaped troughsy positioned beneath the end portions of the structure and with the large ends thereof facing outwardsv crete slabs on a subgrade with beveled sides, co'mprising in combination an elongated straight compressible structure of substantially uniformheight from end to endl adapted to fit between the ,opposed faces of the slabs and form a seal therebetween, a pair of wedge-shaped sheetl metal troughs positioned beneath the end lportions of the structure and with the large ends thereof facing outwards and adaptedy to occupy and fill the spaces between said end yportions of the structure and the beveled sides of the subgrade and to permit any water accumulating under the central portion of the structure to drainto the sides of the subgrade, and tongues 'connected to and formed integrally withv said large ends of the troughs and adapted normally to extend outwards and t within the ends of laterally extending drain pipes on the sides f the subgrade and hold the pipes in. connected and communieatin-g relation with the troughs.

5. A joint for a pair of roadway-forming concrete slabs on a subgrade with beveled sides, comprising in combination an elongated straight compressible structure of substantially uniform height from end to end and adapted to fit between the opposed faces of the slabs and form a seal therebetween, a pair of wedge-like sheet `metal U-shaped troughs positionedr beneath thev endl portionsof the structure and with the large ends thereof facing outwards and adapted to oc-` cupy and fill the spaces between said end portions of the structure and the beveled sides of the subgrade to permit any water accumulating under the central portion of the structure to drain to the sides of the subgrade, and tongues on said large ends of the troughs adapted during pouring of Ithe concrete for the slabs to extend across and close the outer ends ofthe troughs against the iniiow of concrete and upon setting of the concrete to be bent outwards and form a centering medium for the inner ends of laterally extending drain pipes on the sides of the subgrade.

6. A joint for a .pair of adjoining roadwayforming concrete slabs on a subgrade, comprising in combination an elongated com-pressible structure of substantially uniform height from end to end adapted to t'between the opposed faces of the slabs and for-m a seal therebetween, a separately formed substantially coextensive drain under the structure adapted to overlie and rest upon` the subgrade and having a longitudinal downwardly facing channel for permitting any water accumulating under the joint to drain to the sides of the subgrade, and means adjacent to the ends of the drain adapted to engage andy interlock with the inner ends of laterally extending drain pipes on the sides of the subgrade and to hold such'pipes longitudinal alignment with the drain.

' '7'. A- joint for a pair of' adjoining roadwayformingeoncrete slabs onv a subgrade with beveled sides, comprising in combination an elongated straight compressible structure of substantially uniform height from end fto endy adapted toft between the opposed faces of the slabsand form a seal therebetween, a separately'formed substantially coextensive drain under the bottom of the structure adapted to have the central portion thereof rest on the central portion of the subgrade' and having a longitudinaly downwardly facing channel therein for permitting any water accumulating under the central portion of the joint to drain towards the sides of the subgrade, and a' pair of wedge-shaped troughs beneath the end portions of the drain andwith the large endsv thereof facing koutwards and adapted to occupy and ll` the spaces between said end portions of the lstructure and the beveled sides of the subgrade and to receive vwater from the downwardly facing channel of the drainand conduct the same to the sides of the subgrade. j A- 8. A joint for a pairA of` adjoining roadwayforming concrete slabs cna subgrade, comprising in combination an elongated -compressible structure adapted to t between the opposed sides of the slabs and form a seal therebetween, a straight separately formed coextensive sheet metal drain of truly M-shaped cross-section positioned longitudinally over and under the structure and having the central leg thereofdefming a ,V-shaped open top channel in which the bottom ofthe hollowstructure lits and having its side leg defining with the -central leg a pair of downwardly facing channels in communication with the subja'cent portion of the subgrade for permitting any water accumulating under the central portion' of the joint to drain towards the sides of the subgrade, and a pair of wedge-like U-shaped sheet metal troughs with open large ends positioned beneath the enclportions of the drain and with said large ends facing outwards, and adapted to occupy and fill 'the end spaces between said end portions of the structure and the beveled.

sides of ,the subgrade and-to receive water from` the downwardly facing channels of the drain tially uniform height from end to end adapted toi-lt between the opposed faces of the slabs and form a seal therebetween, a separately formed coextensive sheet metal drain of M-shaped crosssection positioned longitudinally of and under the structure and having the central leg thereof dening an open top channel` in which the bottom of the structure fits and having its side legs de- 4 ning with the central leg a pair of downwardly facing'channels at the sides of the open topped channel for Ipermitting any water accumulating under |the joint yto drain to the sides of the subgrade and provided along ythe bottom margins thereof with integral out-turned flanges, and a pair of wedge-like sheet metal U-shaped troughs `beneath the end portions of the drain and with the larg-e ends thereof facing outwards, having integral out-turned flanges along the top margins of the sides thereof in abutment and connected f -lrelation'with the out-turned flanges of the side legs of thej drain j and adapted' to occupyandll the spaces between said end portions fof the structure and thebeyeledsidespf thesubgrade andto receive Water fromthe en dsof the down'- Wardly facing channels-0f lthe drain and conduct thesame to the sides of thesubgrade.

l0. A .joint for a pair of adjoiningV roadway- Aforming concrete slabs, comprising-in combination an elongated ccnnparatively `narrow fopen ended sheet metal 'hollow-structure adapted to 'fit between the opposed faces ofthe slabs and form a seal therebetween, lU shapev; sheet metal end closures fitting snugly inthe ends of the structure land. having 'along the outer margins of the side wallthereof integral outeturned channel equipped flanges extending outwards across the end edges ofthe hollow structure and at substantially right angles to the ysides o-f the latter and adapted for l embedrrnent in and to become interlocked with y of the rrsl'alos, and -compressible plugs i-tting in the thehollow structure to the bottom wall. j 11 joint for apair of adjoining roadwayend yclosures and extending vfrom the top walll of forming-slabs on a''sulogradav con'ipri-sille?.inr com; binationanelongated Qomparatively narrow open ended "hollow structure adapted `,to fit y.between thelopposed faces and form'ajsealtherebetweem ture and adaptedto overlie and rest upon-thesub.

grade and `having the central-g leg'jjthereoffg dei-1 ning an open top channel in which the bottomof ,thehollow structure Ai-ltsandjits sidel llegis deningwith its central 'legapair of downwardly facing channels atthexjsides Io'f 4theaojperi `top channel vfor permitting' any water i accumulating under Vthe joint todrain torthe sides of `,the lsub` grade, and U-shaped corrmressilole:plugsl disposed f at, the ends 0f the `drain andv having'jthe inner downwardly facingchannelsjand their outerivpor-f tions underlying and f vtting- `around" the bottoni portions of vthe irst'mentioned-plugs;,v

fERNEST-He '20 I vportions' thereof fitting in thefen'd Iportions(ofthe.r v

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